Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I congratulate the authors on this research which is clinically valuable. Here are a couple of points that I think contribute to the development of the manuscript:

 

1. Abstract: The abstract says "nine clinical publications… together with one systematic review," but the Results say "Ten clinical publications were identified." needs to be harmonized.
2. Introduction: The Introduction is well written and organized. The key concepts are defined correctly and their association are explained. The funnel logic is correctly applied. The knowledge gap is clearly stated.
3. Introduction: The novelty is stated clearly, but it will be much better if this is done through direct comparision with similar/comparable literature. I found no published review with the same narrow focus (PBM specifically and MMP/TIMP outcomes in periodontitis), so the manuscript niche is defensible. But several reviews overlap substantially, and the most relevant ones are not cited. Through this comparision, the novelty will be much defensible.
4. Methods: The inclusion of "other laser-based periodontal therapies" contradicts the PBM focus.
5. Methods: There are no a priori criteria defining PBM, such as thresholds for irradiance, fluence, and power, non contact application, or non thermal effect. This gap is seen in the classification problems in the other sections also. You can consider using explicit criteria, for example based on WALT guidance.
6. Methods: Why ref [6] is not included? There are other papers in the literature that are not included. Better to double check.
7. Methods: You mention that "broader mechanistic synthesis included experimental and clinical studies”. Does this include in vitro or animal study measuring MMPs or TIMPs after PBM? Because these kind of studies are not reported. Either explicitely state that only human clinical studies are included, or maybe you can dedicate a new section for this.
8. Pathogenesis section: It’s vey long and textbook-like. NLRP3, Th17, and resolvins are marginal to the review question, so the section can be shortned. "PPRs" should be "PRRs." "The present results suggest…" is strange, since this is not the authors' own data.
9. MMP/TIMP overview and dentistry: There are some citation problems here: "[12–15]" for MT-MMPs are on neutrophil and NLRP3 papers. "[16,19–22]" for hypochlorous acid activation includes NLRP3 and resolvin papers. An empty citation "[]" appears in the MMP-9 paragraph. Refs 21 and 31 are duplicates. Please double check these.
10. No comparision with prior literature is done. Just like my introduction comment, it will be interesting to compare the findings of this review with comparable/similar reviews (narrative or systematics). You can consider adding a section of “discussion” for this. This is is especially important to show the contribution of the present review.
11. Limitations: This section is very brief. Please consider adding small sample sizes (n = 17–19 in several trials), absence of risk of bias assessment, language and publication bias, split-mouth contamination and assay heterogeneity.
12. Conclusion: Conclusion sentences use the correct wording, are based on the results and avoid overestimation.

 

Sincerely,

Author Response

Reviewer 1

I congratulate the authors on this research which is clinically valuable. Here are a couple of points that I think contribute to the development of the manuscript:

 

1.Abstract: The abstract says "nine clinical publications… together with one systematic review," but the Results say "Ten clinical publications were identified." needs to be harmonized

Reply

We thank the reviewer for identifying this inconsistency. The review includes ten primary clinical publications (one additional was included) and one systematic review considered separately as a secondary evidence source. We made adequate corrections.

2. Introduction: The Introduction is well written and organized. The key concepts are defined correctly and their association are explained. The funnel logic is correctly applied. The knowledge gap is clearly stated.

Reply

The authors thank the reviewer for the positive assessment of our manuscript.

3. Introduction: The novelty is stated clearly, but it will be much better if this is done through direct comparision with similar/comparable literature. I found no published review with the same narrow focus (PBM specifically and MMP/TIMP outcomes in periodontitis), so the manuscript niche is defensible. But several reviews overlap substantially, and the most relevant ones are not cited. Through this comparision, the novelty will be much defensible.

Reply

We thank the reviewer for recognizing the specific scientific focus and potential novelty of our narrative review. We agree that its contribution should be more explicitly positioned in relation to previously published reviews addressing laser-based periodontal therapy and inflammatory biomarkers. In the revised manuscript, we have clearly specified the criteria used to select and critically evaluate the clinical studies, including the intended purpose of laser irradiation, wavelength, output power, irradiance, fluence, exposure duration, emission mode, application technique, and treatment schedule. We excluded studies primarily involving other laser-based approaches, particularly antimicrobial photodynamic therapy (aPDT), laser-assisted periodontal decontamination, and procedures involving tissue ablation or predominantly photothermal effects, when a distinct PBM component could not be reliably identified. Systematic reviews addressing these broader laser modalities were also excluded from the primary clinical evidence synthesis, although relevant reviews were discussed separately for comparison. These clarifications have been incorporated into the final part of the Introduction (marked in blue) and the revised Literature Search Methodology section (marked in blue).

4. Methods: The inclusion of "other laser-based periodontal therapies" contradicts the PBM focus.

Reply

We agree that the original wording was not sufficiently precise, although the distinction between clearly characterized PBM protocols and other laser-based interventions with a potential PBM component was addressed in the subsequent evaluation of individual clinical studies. To avoid ambiguity and better define the scope of the review, we have completely revised the relevant text in the Review Methodology and Scope section. The clinical part comprised human studies that examined changes in MMP- and/or TIMP-related biomarkers after adjunctive PBM or laser-based interventions containing a separately identifiable PBM component or a potentially PBM-related component. We distinguished these interventions from clearly characterized PBM protocols and interpreted them according to their reported treatment purpose and irradiation characteristics.

5. Methods: There are no a priori criteria defining PBM, such as thresholds for irradiance, fluence, and power, non-contact application, or non-thermal effect. This gap is seen in the classification problems in the other sections also. You can consider using explicit criteria, for example based on WALT guidance.

Reply

We agree that the criteria used to distinguish PBM from other laser-based periodontal interventions should be more clearly defined in the Methods section. This is why we completely rewrote the Review Methodology and Scope section. We considered recommendations from the World Association for Photobiomodulation Therapy (WALT), along with established guidelines for reporting PBM parameters (Jenkins and Carroll, 2011; Robijns et al., 2022). However, no universally applicable numerical thresholds for output power, irradiance, or fluence reliably distinguish PBM from thermal or ablative laser treatments. The biological effects depend on several interrelated factors, including wavelength, irradiation parameters, tissue characteristics, and application technique. Similarly, contact or non-contact application alone does not determine whether an intervention is photobiomodulatory. This is stated in the text.

Regarding a priori criteria, our study was designed as a narrative review with a structured literature search rather than a protocol-driven systematic review. Therefore, we have not retrospectively introduced numerical eligibility thresholds or presented them as prospectively established criteria. Instead, we have clarified the operational principles used to classify the interventions, acknowledging uncertainty when essential irradiation parameters were insufficiently reported. We believe that the revised section “Review Methodology and Scope” now adequately addresses all of these concerns.

6. Methods: Why ref [6] is not included? There are other papers in the literature that are not included. Better to double check.

Reply

Reference [6] (Ren et al., 2017) was not included among the primary clinical publications because this meta-analysis primarily evaluated clinical periodontal outcomes and selected inflammatory mediators following adjunctive LLLT, rather than specifically analyzing MMP/TIMP-related responses. We also reviewed other relevant systematic reviews and meta-analyses, including those by da Silva et al. [46] and Corbella et al. [67]. These publications primarily addressed clinical treatment efficacy, broader inflammatory outcomes, or antimicrobial photodynamic therapy rather than specifically examining PBM-related modulation of the MMP/TIMP system (marked in blue).

7. Methods: You mention that "broader mechanistic synthesis included experimental and clinical studies”. Does this include in vitro or animal study measuring MMPs or TIMPs after PBM? Because these kind of studies are not reported. Either explicitely state that only human clinical studies are included, or maybe you can dedicate a new section for this.

Reply

The initial literature screening considered both clinical and experimental in vivo studies. However, experimental animal studies were not included in the final analysis, which focused exclusively on human clinical studies investigating MMP/TIMP-related outcomes following PBM-related interventions. To avoid ambiguity, we have this clearly stated in the Review Methodology and Scope section.

8. Pathogenesis section: It’s vey long and textbook-like. NLRP3, Th17, and resolvins are marginal to the review question, so the section can be shortened. "PPRs" should be "PRRs." "The present results suggest…" is strange, since this is not the authors' own data.

Reply

We accepted this suggestion and considerably shortened this part in the section “Pathogenesis of periodontitis. The revised and shortened part is marked in blue. We have also corrected the abbreviation “PPRs” to “PRRs” and replaced the inappropriate expression The expression.. “The present results suggest”.. was ambiguous, as it was intended to refer to the findings of other studies. Corrected.  

9. MMP/TIMP overview and dentistry: There are some citation problems here: "[12–15]" for MT-MMPs are on neutrophil and NLRP3 papers. "[16,19–22]" for hypochlorous acid activation includes NLRP3 and resolvin papers. An empty citation "[]" appears in the MMP-9 paragraph. Refs 21 and 31 are duplicates. Please double check these.

Reply

We checked and corrected the mistakes you outlined. These mistakes occurred unintentionally; thank you for pointing them out.

10. No comparison with prior literature is done. Just like my introduction comment, it will be interesting to compare the findings of this review with comparable/similar reviews (narrative or systematics). You can consider adding a section of “discussion” for this. This is especially important to show the contribution of the present review.

Reply

We emphasize that, to the best of our knowledge, no previous review has specifically addressed the effects of photobiomodulation (PBM) on MMP/TIMP-related responses in patients with periodontitis. This represents the principal novelty and scientific contribution of our narrative review, as already indicated in the original manuscript and further emphasized in the revised version.

To clarify this distinction, we have more explicitly defined the inclusion and exclusion criteria in the Methods section and expanded the comparison with previous reviews. Systematic reviews and meta-analyses focusing on PBM or laser therapy in periodontitis, including those by Ren et al., Dalvi et al., da Silva et al., and Corbella et al., primarily evaluated clinical treatment efficacy. Although some cited individual publications investigating MMPs, they did not specifically analyze or synthesize MMP/TIMP-related outcomes. We have added this comparison immediately after the analysis of Akram et al. We also clarified that other reviews addressing MMP-related biomarkers focused on different light-based interventions, particularly antimicrobial photodynamic therapy, which differs from PBM in its primary mechanism of action and was therefore outside the defined scope of our review.

We believe these clarifications adequately distinguish previous publications from the present review while preserving the manuscript's focused narrative structure without introducing a separate Discussion section.

11. Limitations: This section is very brief. Please consider adding small sample sizes (n = 17–19 in several trials), absence of risk of bias assessment, language and publication bias, split-mouth contamination, and assay heterogeneity.

Reply

We thank the reviewer for this constructive suggestion. We agree that the limitations of the available clinical evidence should be more explicitly acknowledged. Accordingly, we have expanded the Limitations of the Review section to address small sample sizes, potential methodological limitations of split-mouth designs, and possible publication and language-selection biases.

We also emphasize that heterogeneity in irradiation protocols, comparator treatments, follow-up periods, and biomarker assessment methods was already acknowledged in the original manuscript. We address additional study-specific limitations in the revised analyses of individual clinical publications.

As this is a narrative review, a formal risk-of-bias assessment was not performed; this is now explicitly acknowledged as a limitation.

12. Conclusion: Conclusion sentences use the correct wording, are based on the results and avoid overestimation.

Reply

We thank the reviewer for the positive assessment of our Conclusions and for recognizing that our interpretation is appropriately cautious and supported by the available clinical evidence. Nevertheless, we have made minor revisions to the Conclusion to ensure that it is consistent with the revised manuscript.

 

 

Reviewer 2 Report

Comments and Suggestions for Authors

Attached.

Comments for author File: Comments.pdf

Author Response

Reviewer 2 – Comments and Author Responses

The manuscript “Photobiomodulation in Periodontitis: Targeting Matrix Metalloproteinases, Tissue Inhibitors of Metalloproteinases, and Extracellular Matrix Remodeling” addresses a relevant topic at the intersection of periodontal inflammation, host modulation, and light-based adjunctive treatment. Its focus on the relationship between clinical outcomes and MMP/TIMP-associated biomarkers is potentially valuable. The authors appropriately acknowledge heterogeneous treatment protocols and inconsistent biochemical findings, and the overall conclusion is reasonably cautious.

However, substantial revision is required before the manuscript can be considered for publication. The principal concerns relate to the transparency of evidence selection, the classification of laser interventions as photobiomodulation, the absence of a structured assessment of study quality, and several inconsistencies in the interpretation and presentation of the evidence.

General Comments of the Authors on the Reviewer's Comments

The authors thank the reviewer for the thorough and detailed evaluation of our manuscript. We must admit, however, that we were somewhat surprised by the unusually extensive level of detail in the review and the emphasis on certain methodological requirements that are generally more applicable to systematic reviews than to narrative reviews. Furthermore, we do not believe that we should be expected to perform a retrospective statistical reanalysis of previously published studies when the original data required for such analyses are generally unavailable. We also note that several of these methodological requests have been raised repeatedly throughout the review, albeit in slightly different formulations.

Nevertheless, we have carefully considered all comments and suggestions. They have helped us correct several shortcomings, formulate certain statements more precisely, and clarify ambiguities or potentially misleading interpretations, ultimately improving the overall quality of the manuscript. This allowed us to substantially improve the manuscript by shortening and/or rewriting certain sections, removing references that addressed overlapping topics, and adding new references to support the additional findings and information in the revised review.

In accordance with the reviewer's comments, we have provided detailed, point-by-point responses, addressing even the most minor issues that required further explanation or clarification.

All newly added text is highlighted in red, whereas revisions made in response to the first reviewer are highlighted in blue.

1. Improve the transparency of the literature search and study selection.

The manuscript identifies itself as a narrative review with a structured search, but the methodology currently provides a list of search terms rather than reproducible search strategies. Please report the exact search dates, database-specific search strings, applied restrictions, and the procedure used for Google Scholar searching, including how many results were screened. Describe how duplicates were removed, how eligibility was assessed, who performed study selection and data extraction, and how disagreements or uncertain classifications were resolved.

A concise selection summary should explain how the nine primary clinical publications were identified. This request does not require conversion into a systematic review; however, the structured search and numerical claims about the evidence base need to be traceable. Because the search extends to June 2026 whereas the included primary clinical publications end in 2023, please clarify whether no eligible publications were identified for the intervening period and verify that the search is sufficiently current.

Reply

In the original manuscript, we provided the key search terms used to identify relevant literature, as is generally accepted practice for narrative reviews. Unlike systematic reviews, narrative reviews do not necessarily require highly structured search and selection procedures or the application of a PRISMA flow diagram.

Nevertheless, we accepted the reviewer's suggestion to provide a more transparent and detailed description of our literature search and study selection process. Furthermore, we repeated the literature search to determine whether any additional relevant publications had appeared since our previous final search. Consequently, the section entitled “Review Methodology and Scope” was substantially rewritten to provide a clearer account of the search strategy, eligibility criteria, study selection, and scope of the review.

The revised methodology now provides a more detailed description of the search strategy, including the databases searched, combinations of search terms, eligibility criteria, and procedures for study selection and data extraction. The searches covered PubMed/MEDLINE, Scopus, Web of Science, the Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar, supplemented by manual screening of references cited in relevant publications. The final search update was performed on 8 October 2026.

The database searches yielded approximately 479 results: 13 in PubMed/MEDLINE, 32 in Scopus, 95 in Web of Science, 26 in CENTRAL, and approximately 313 in Google Scholar. The search strategy combined controlled vocabulary, where available, and free-text terms organized into three components: (1) “periodontitis” OR “periodontal disease” OR “chronic periodontitis”; (2) “photobiomodulation” OR “low-level laser therapy” OR “low-level light therapy” OR “laser therapy”; and (3) “matrix metalloproteinase” OR “MMP” OR “TIMP” OR “tissue inhibitor of metalloproteinase”. These components were combined using the Boolean operator AND, with syntax adapted to individual databases. Supplementary searches included clinical study-related terms. Google Scholar was searched using the keywords “periodontitis”, “photobiomodulation”, “MMP”, and “TIMP”.

Duplicate records were identified using EndNote reference management software, with additional manual verification of potentially eligible publications based on their bibliographic details. After duplicate removal, 116 records underwent title and abstract screening, and 58 publications were assessed in full text.

The eligibility criteria have been clarified, particularly regarding the distinction between PBM and other laser-based periodontal interventions. We also specified that study selection and data extraction were performed by BI and BK, with further review by MČ. Uncertain eligibility decisions, particularly those concerning laser intervention classification, were discussed among the authors, and unresolved methodological uncertainties were explicitly acknowledged.

Importantly, the additional literature search and detailed re-examination of the original publications led to a revision of the clinical evidence base. Two previously omitted studies, Qadri et al. (2007) and Ezber et al. (2022), were included, whereas Sayar et al. (2022) was excluded from the primary PBM synthesis because its laser interventions were primarily directed toward periodontal pocket decontamination, without sufficient evidence to isolate a specific PBM effect. Consequently, the number of primary clinical publications increased from nine to ten. The systematic review by Akram et al. (2016) was retained separately as secondary evidence.

Two potentially relevant registered clinical trials investigating laser-associated MMP-9 and MMP-13 responses were also identified in CENTRAL but were not included because published results were unavailable. These changes did not alter the principal conclusions. MMP-8 remains the most frequently investigated biomarker, while evidence for additional PBM-associated modulation of MMP/TIMP responses beyond conventional periodontal treatment remains inconsistent. The revised synthesis provides a more precise distinction between clinical improvements, changes in biomarker measurements, and effects specifically attributable to PBM.

Finally, we have taken into consideration the principles of the Scale for the Assessment of Narrative Review Articles (SANRA; Baethge et al., 2019), particularly regarding transparent literature identification, appropriate referencing, and critical interpretation of the evidence. These methodological improvements preserve the narrative nature of the review while strengthening its transparency and scientific rigor.

2. Define operational criteria for classifying an intervention as PBM.

The distinction between PBM, thermal laser treatment, laser-assisted debridement, and antimicrobial photodynamic therapy is central to the review. Nevertheless, the categories “PBM-compatible” and “potentially PBM” are not supported by explicit classification criteria.

Please specify how wavelength, delivered power, irradiance, fluence, exposure time, applicator geometry, contact mode, pulse characteristics, and treatment purpose were used to determine eligibility and classification. Low nominal power alone does not establish a non-thermal mechanism, and an intervention described as LLLT by its original authors should not automatically be accepted as unequivocal PBM.

This issue is particularly relevant to the 1.5-W protocol attributed to Misra et al. [58] and the 1-W continuous-wave diode protocol in Sayar et al. [62]. These values do not themselves prove that the interventions were thermal, but they require examination of the complete delivery parameters. Where the original report does not permit reliable classification, the uncertainty should be explicitly recorded.

Please separate clearly characterized PBM protocols from insufficiently characterized laser protocols and assess whether the principal conclusions remain supported when the latter are excluded from the core PBM synthesis.

Reply

We agree that distinguishing photobiomodulation (PBM) from other laser-based periodontal interventions is essential for the validity of the present review. In response, we have substantially clarified the operational criteria for PBM classification in the Review Methodology and Scope section and carefully re-examined the irradiation characteristics and therapeutic purposes reported in the original clinical publications.

First, we have introduced a more explicit operational definition of PBM. For this review, PBM was defined as light-based treatment primarily intended to modulate biological responses without deliberate tissue ablation, coagulation, or antimicrobial photodynamic action. The classification of interventions was based on their reported therapeutic purpose and irradiation characteristics, including wavelength, output power, irradiance, fluence, exposure duration, emission mode, beam geometry, and application technique, consistent with the principles outlined in the WALT recommendations and established PBM dosimetry and reporting guidelines (References 10 and 11).

Importantly, we did not regard low nominal laser power or the designation "low-level laser therapy" used by the original authors as sufficient evidence of an exclusively non-thermal PBM mechanism. Conversely, relatively high reported output power was not considered sufficient, by itself, to establish a predominantly thermal effect or justify automatic exclusion. Instead, we considered the available information on irradiation parameters, delivery technique, treatment purpose, and the potential for photothermal or tissue-removal effects. Incomplete or inconsistent reporting of essential dosimetric parameters was treated as a methodological limitation, rather than interpreted as evidence supporting a specific mechanism.

Second, we reassessed the classification of the clinical studies and distinguished more clearly between PBM, PBM-compatible interventions with incomplete dosimetric characterization, and laser protocols primarily intended for decontamination or tissue removal. Studies involving predominantly ablative or decontamination-oriented procedures were excluded from the primary PBM synthesis when a distinct photobiomodulatory component could not be reliably identified or evaluated. For studies involving combined laser modalities or incompletely characterized irradiation protocols, we emphasized which additional treatment characteristics and dosimetric parameters should be reported to justify classifying the intervention as PBM. These requirements and the limitations of the available information were specifically addressed in our critical evaluation of each relevant clinical study.

Third, we specifically re-evaluated the studies highlighted by the reviewer.

Regarding Misra et al. [58], we agree that the reported 1.5-W laser output requires careful interpretation. Although the intervention was presented as a low-level laser treatment intended to promote postoperative periodontal healing, the available description does not provide sufficient information on beam geometry, irradiance, or fluence to establish the actual energy density delivered to the treated tissues. Furthermore, nominal output power alone does not determine tissue exposure, particularly when irradiation is performed using a moving, non-contact technique. We have therefore retained this study as a PBM-intended but incompletely characterized intervention, with an explicit qualification that its predominantly non-thermal mechanism cannot be confirmed from the reported parameters. Its findings are now interpreted as treatment-associated changes rather than definitive evidence of a specific PBM mechanism. For this study, as for all other studies included in our analysis, we have added further discussion of study limitations and interpretation of the findings, both in the table and in the narrative section of the revised manuscript.

Regarding Sayar et al. [62], our re-examination showed that the 940-nm diode laser was applied using a 1-W continuous-wave intrapocket protocol primarily intended for periodontal decontamination. The study also investigated an Er,Cr laser intervention involving a different mechanism of tissue interaction. Although reductions in inflammatory biomarkers, including MMP-13, were reported, these findings cannot be reliably attributed to isolated PBM effects. Accordingly, we have excluded Sayar et al. from the primary PBM clinical synthesis, while retaining its relevance to the broader discussion of laser-assisted periodontal interventions.

Fourth, we extended this reassessment to other studies employing intrapocket or combined laser procedures. We now distinguish low-output interventions with a plausible PBM-related therapeutic purpose from higher-output laser protocols involving potential photothermal, antimicrobial, or tissue-removal effects. In particular, studies primarily addressing laser-assisted decontamination or debridement are discussed separately rather than being presented as direct evidence of PBM-specific modulation of MMP/TIMP responses. Combined laser interventions are interpreted according to the information provided by their individual treatment arms, with appropriate caution regarding attribution of effects to PBM. This is consistent with the clearly established definition of PBM and the inclusion and exclusion criteria outlined in the “Review Methodology and Scope” section of the revised manuscript. It is important to stress that no single irradiation parameter or universal numerical threshold was used to classify an intervention as PBM. Instead, classification was based on the combined assessment of irradiation characteristics, delivery conditions, and the intended therapeutic mechanism, with particular attention to whether tissue ablation, coagulation, or decontamination constituted the primary treatment objective.

The revised classification did not change the principal conclusion of the review. Although several clinical studies reported favorable periodontal outcomes and changes in MMP/TIMP-related biomarkers following PBM or PBM-compatible interventions, the available evidence remains insufficient to establish a consistent additional PBM-specific biochemical effect beyond conventional periodontal treatment. We believe that the revised operational criteria and more cautious interpretation substantially strengthen the methodological rigor and clinical relevance of the manuscript.

3. Add a structured critical appraisal of the clinical evidence.

The review discusses heterogeneity but does not provide a study-level assessment of methodological credibility. This limits the reader’s ability to distinguish more reliable findings from observations susceptible to bias.

Please assess, using design-appropriate criteria, randomization, allocation concealment, blinding, baseline comparability, attrition, outcome measurement, selective reporting, and analytical limitations. For split-mouth studies, consider whether the analyses accounted for paired observations and multiple sites within patients. For crossover designs, address potential period and carryover effects where relevant.

A compact appraisal table would be useful. A formal certainty-grading framework is not essential for this narrative review, but the strength of each principal conclusion should be explicitly linked to study quality, sample size, precision, and directness of evidence.

Reply

We agree that the methodological quality of individual clinical studies is essential for interpreting the reliability of the reported findings, particularly given the considerable heterogeneity of the available evidence. In response to this comment, we have substantially strengthened the critical appraisal of the included clinical publications. Each study was re-examined using its original report, and the revised clinical evidence section now provides a more detailed study-level discussion of methodological strengths and limitations.

Particular attention was paid, where applicable and adequately reported, to randomization procedures, allocation concealment, blinding, baseline comparability, sample size, follow-up duration, outcome assessment, and the appropriateness of statistical analyses. For split-mouth and other within-patient designs, we specifically considered whether the statistical methods adequately accounted for paired observations and multiple periodontal sites within individual patients. Incomplete reporting of these methodological characteristics was also acknowledged as a limitation.

Importantly, the revised interpretation distinguishes statistically significant within-group changes from additional effects demonstrated by direct between-group comparisons. We have also taken into account the limitations of small sample size, limited precision, incomplete dosimetry of irradiation, short follow-up periods and differences in biomarker measurement methods. These factors were considered in assessing the strength and clinical importance of the reported findings.

We recognize the methodological value of the reviewer’s suggestion of a formal assessment of risk of bias. However, formal risk of bias assessment is not a prerequisite for narrative reviews, unlike systematic reviews, where it represents an important component of methodological evaluation. Therefore, we considered a structured qualitative appraisal of the individual studies more appropriate to the objectives of our review. Accordingly, no formal risk-of-bias scoring or categorical grading was performed. Instead, potential sources of bias and methodological uncertainty are explicitly discussed in the text accompanying each study, allowing readers to evaluate the credibility and limitations of the evidence in its original clinical context.

We also considered the suggestion to provide a separate appraisal table. However, since the methodological characteristics, relevant limitations, and their implications for interpreting the results are now discussed alongside the individual clinical studies, we believe that an additional table would substantially duplicate information already presented in the revised manuscript.

Finally, the overall synthesis and conclusions have been reconsidered in light of the methodological quality, sample sizes, precision, and directness of the available evidence. Consequently, we have maintained cautious conclusions, particularly concerning the lack of consistent evidence for additional PBM-specific modulation of MMP/TIMP-related biomarkers beyond that achieved with conventional periodontal treatment.

4. Distinguish adjunctive efficacy from comparisons between different treatment strategies.

The Sopi studies [59,60] compare treatment strategies that do not provide an identical background-treatment control for isolating the effect of PBM. The manuscript acknowledges this limitation but subsequently states that their findings “confirm the clinical and biochemical effectiveness of the low-power laser protocol.”

Please moderate this interpretation. These studies can inform comparisons between treatment strategies, but they cannot establish the incremental effect of PBM over an otherwise identical periodontal intervention. They also do not establish that PBM can replace a clinically indicated surgical procedure.

Similarly, combined Er and Nd treatment in Yang et al. [61] should be discussed separately from an isolated PBM comparison. Any PBM-specific inference should be based on the relevant treatment arms rather than on the overall performance of a combined laser protocol.

Reply

 In response, we carefully re-evaluated the original publications by Sopi et al. [now 58, 59] and Yang et al. [now 60] and revised the corresponding descriptions and interpretations in the clinical evidence section.

Regarding Sopi et al., we have explicitly emphasized that these studies compared different periodontal treatment strategies rather than PBM and control groups receiving otherwise identical background treatment. Consequently, the observed clinical and biochemical differences cannot be attributed specifically to an additional PBM effect. We removed the previous statement suggesting that these findings confirmed the clinical and biochemical effectiveness of the low-power laser protocol and replaced it with a more cautious interpretation.

We also noted that these studies do not show that PBM can replace periodontal surgery when surgical intervention is clinically indicated. Their results are now reviewed in the light of comparative treatment outcomes with consideration given to differences in therapeutic procedures, study design and statistical comparisons . We also pointed out that the qualitative nature of the MMP-8 test does not allow a quantitative evaluation of biomarker levels or enzymatic activity, limiting the interpretation of the biochemical results. Furthermore, we discussed the possibility of overlap in study populations, as some participants may have been included in both studies.

Nevertheless, we retained these studies because they provide relevant comparative clinical and biochemical findings, while clearly acknowledging that their design does not allow PBM-specific effects to be isolated.

Regarding Yang et al. [now 60], we have revised the text to distinguish the effects of Nd irradiation considered PBM-related from those of the combined Er and Nd treatment. We explicitly stated that only the SRP plus Nd arm allows assessment of PBM-related responses without an additional laser debridement procedure. We also emphasized that the combined treatment produced the greatest clinical improvements, but these were not accompanied by greater MMP-8 suppression. Furthermore, we discussed the incomplete irradiation dosimetry, discrepancies in the reported laser parameters, and limitations of the statistical analysis, which restrict conclusions regarding PBM-specific effects.

5. Correct statistical wording and distinguish within-group improvement from between-group effects.

For Qadri et al. [54], Table 1 reports a between-group p-value of 0.052 and labels the result non-significant, whereas the narrative describes it as “marginally significant.” Unless a different significance threshold was explicitly specified in the original study, this should be reported as a non-significant between-group difference, with the exact p-value.

Throughout the synthesis, distinguish reductions occurring after periodontal treatment in both arms from additional effects attributable to PBM. A statistically significant change within one group does not establish superiority over another group. Conversely, a non-significant between-group result does not demonstrate equivalence.

Where available, include the magnitude of relevant between-group differences and their uncertainty, rather than relying primarily on directional arrows and significance labels. Clearly identify exploratory findings, including smoker subgroup observations and effects at the deepest periodontal sites.

Reply

We agree that changes occurring within individual treatment groups must be clearly distinguished from between-group differences when evaluating the additional effects of PBM. Accordingly, we carefully re-examined the statistical results reported in the original clinical publications and revised the corresponding descriptions in the clinical evidence section and Table 1.

First, regarding Qadri et al. (2005) [now 52], we corrected the interpretation of the between-group difference in MMP-8 levels. The previously used expression “marginally significant” has been removed, and the result is now correctly reported as statistically non-significant (p = 0.052).

Second, throughout the revised clinical synthesis, we have distinguished within-group changes following periodontal treatment from additional effects demonstrated by direct between-group comparisons. We also clarified that a statistically significant within-group improvement does not establish treatment superiority, whereas a non-significant between-group difference should not be interpreted as evidence of therapeutic equivalence.

Third, we reassessed the magnitude and statistical significance of the reported biomarker and clinical changes, incorporating numerical differences, percentage changes, and exact p-values where available. For example, we now report the MMP-8 reductions observed by Qadri et al. (2007) [now 53] (44.9% and 8.6%), together with the non-significant between-treatment comparison (p = 0.066). We also included the between-group p-values reported by Ezber et al. [now 61] at one and three months (p = 0.149 and p = 0.390, respectively). In addition, the small site-specific clinical improvements reported by Chen et al. [now 56] are presented quantitatively and interpreted as exploratory findings.

We also considered the reviewer's request to report effect sizes and their 95% confidence intervals. We do not consider it methodologically reasonable to request retrospective calculation of effect sizes and confidence intervals from published studies when the authors have not provided the data required for valid estimation. Such calculations often require individual patient-level data, paired observations, or information on within-patient correlations, which original publications generally do not report. This is particularly important for split-mouth and site-level study designs. Reconstructing effect sizes and confidence intervals without these data would require unverifiable assumptions and could lead to misleading estimates. We therefore consider it more scientifically appropriate to report the original numerical findings and statistical results, while critically discussing their limitations, rather than generating potentially unreliable estimates from incomplete published data.

Fourth, particular attention was paid to studies in which favorable clinical or biochemical changes were not supported by significant between-group differences. This distinction is now more clearly reflected in the analyses of Qadri, Aykol, Chen, and other relevant studies. The subgroup observations, especially for smokers or deeper periodontal pocket depths, are exploratory and not evidence of further PBM effects.

These revisions are also reflected in the overall synthesis and Conclusion, which now put more emphasis on direct between-group evidence and the methodological limitations of the original studies. Importantly, the revised statistical interpretations did not alter the major conclusions of our review. Despite PBM-related interventions being able to induce positive clinical and biochemical responses, the current comparative evidence is not sufficient to support further advantages in terms of MMP/TIMP benefits compared to conventional periodontal treatment.

6. Strengthen biomarker characterization and interpretation.

The manuscript appropriately distinguishes active from total MMP-8 in the mechanistic discussion, but this distinction is not consistently applied to the clinical evidence. Table 1 should identify the assay used, the molecular form measured where established, measurement units, sampling time points, and whether the reported outcome represents concentration, total amount, enzymatic activity, or qualitative positivity.

For GCF measurements, discuss the potential influence of fluid volume and sampling procedures, particularly when treatment changes GCF flow. A decrease in biomarker concentration or amount should not automatically be equated with reduced enzymatic activity.

For the qualitative dipstick studies [59,60], report the assay threshold and specificity for active or total MMP-8 where documented. A negative result indicates a value below the assay’s detection or decision threshold; it does not establish absence of the enzyme or quantify the extent of its reduction.

Claims that MMP/TIMP ratios reflect net proteolytic activity should also be qualified. Ratios of measured protein concentrations do not necessarily capture the amount of active, uninhibited enzyme.

Reply

We agree that accurate characterization of MMP/TIMP measurements is essential for interpreting the biochemical effects of PBM.

In response, we re-examined the biomarker assessment methods reported in the original clinical publications and revised Table 1 to provide more detailed information on the analytical methods, molecular forms where established, measurement units, sampling time points, and the distinction between quantitative and qualitative outcomes. Where this information was incomplete or unavailable in the original publications, the corresponding limitations were acknowledged.

We have also clarified throughout the clinical evidence section that changes in MMP protein concentrations or amounts measured by immunoassays should not automatically be interpreted as changes in enzymatic activity. Additional discussion has been included regarding the influence of GCF sampling procedures and fluid volume on biomarker measurements, particularly when periodontal treatment alters GCF flow.

Regarding the qualitative dipstick assays used in the Sopi studies [now 58,59], we have explicitly stated that these methods do not provide quantitative information on MMP-8 concentrations or enzymatic activity. We further clarified that a negative result indicates a value below the assay's positivity threshold rather than complete absence of MMP-8. The available publications did not allow us to establish the assay threshold or its specificity for active versus total MMP-8 with sufficient confidence, so we avoided unsupported assumptions about these characteristics.

Finally, we have qualified the interpretation of MMP/TIMP ratios, emphasizing that ratios derived from measured protein concentrations do not necessarily represent net proteolytic activity without information on enzyme activation and inhibition.

These revisions improve the interpretation and comparability of the reported biochemical findings and reinforce the need for standardized quantitative assessments of active MMPs and their corresponding inhibitors in future clinical studies.

7. Reconcile the study counts and verify Table 1 against the primary reports.

The abstract correctly distinguishes nine clinical publications from one systematic review, whereas the clinical evidence section initially refers to “Ten clinical publications.” Please consistently identify nine primary clinical publications and one secondary evidence source. Akram et al. [63] should be presented separately from the primary studies, with explicit recognition of overlap with already included publications.

Please also establish whether the two Sopi publications describe independent cohorts or potentially overlapping participants. Overlap should be assessed rather than assumed, and any unresolved uncertainty should be stated.

The clinical summaries require verification against the original results. For example, the description of Sopi et al. [59] broadly attributes greater improvements in probing depth and gingival index to laser treatment compared with surgery. However, the original article’s Table 3 reports non-significant laser-versus-surgery differences for these outcomes at six months. Where an original report contains inconsistencies between its tables and narrative, the review should identify the discrepancy and avoid an unqualified statement of superiority.

Finally, clarify the CAL notation. “↑CAL” is ambiguous because a numerical increase in clinical attachment level measurements may indicate greater attachment loss. Use “clinical attachment gain” or “reduction in CAL measurements,” as appropriate.

Reply

 In response, we re-examined the primary clinical reports, revised Table 1 and the corresponding narrative descriptions, and reconciled the number of included publications throughout the manuscript.

First, regarding the number of studies, the additional literature search and reassessment of eligibility criteria resulted in the inclusion of two previously omitted clinical publications, Qadri et al. (2007) and Ezber et al. (2022), and the exclusion of Sayar et al. (2022) from the primary PBM synthesis. Therefore the final evidence base included ten main clinical publications instead of the nine reported earlier. We have used this updated number throughout the revised manuscript including the Abstract, methodology, clinical evidence section and Table 1.

The systematic review by Akram et al. (2016) is now presented as a secondary source of evidence, separate from the ten primary clinical publications. We have also clarified that this review included some original studies already evaluated in our manuscript, particularly Qadri et al. (2005) and Aykol et al. (2011). Accordingly, its findings are discussed as contextual secondary evidence rather than independent confirmation of the primary clinical results.

Second, regarding the two Sopi publications, we carefully compared their reported study populations, treatment protocols, study periods, and methodological characteristics to assess the possibility of overlapping participants. Although the publications involved similar therapeutic approaches and originated from the same research group, the available information did not allow us to establish with certainty whether the cohorts were entirely independent. We therefore explicitly acknowledged the possibility of cohort overlap as an unresolved limitation and avoided treating the two publications as necessarily independent patient populations.

Third, we corrected the interpretation of Sopi et al. (2020). We agree that the original article's Table 3 does not support a general statement of superiority of laser treatment over modified Widman flap surgery for probing depth and gingival index at six months. The corresponding description has therefore been revised to distinguish improvements relative to conventional scaling and root planing from comparisons with surgical treatment. We now explicitly state that the laser-versus-surgery differences in probing depth and gingival index were not statistically significant at the six-month follow-up.

More generally, we verified the clinical and biochemical results reported in Table 1 against the original publications, with particular attention to the direction of changes, statistical significance, comparison groups, biomarker measurement methods, and methodological limitations. Where relevant, the revised narrative now distinguishes within-group changes from between-group differences and avoids unsupported conclusions regarding treatment superiority.

Finally, we corrected the CAL notation throughout Table 1 and the clinical evidence section. The previously vague term “↑CAL” has been replaced by more specific terms such as “reduction in CAL measurements” and concrete p-values have been added according to the results reported in the original studies. This avoids confusion between improvement in periodontal attachment and numerical increases in CAL measurements that are suggestive of greater attachment loss.

8. Separate biological plausibility from demonstrated clinical mechanisms.

The mechanistic sections discuss NF-κB modulation, macrophage polarization, the RANKL/OPG axis, collagen synthesis, and osteogenic repair. These mechanisms provide useful biological context, but their relevance to the included human PBM studies is not always established directly.

Please distinguish findings from cell studies, animal models, general PBM research, and human periodontal trials. Statements implying that PBM restores the MMP/TIMP balance or induces periodontal regeneration should be qualified when the included clinical studies did not measure those outcomes.

The proposed reparative interpretation of increased MMP-9 in Ismaili and Bokonjić [56] is plausible but remains hypothetical. The absence of enzyme-activity measurements and the short follow-up prevent a mechanistic conclusion. Likewise, increased OPG alone does not demonstrate a change in the RANKL/OPG ratio or reduced osteoclast activity.

Reply

We carefully re-examined the mechanistic and clinical sections of the manuscript and revised several statements to avoid implying that experimentally established or biologically plausible mechanisms have been confirmed in clinical periodontal trials.

Regarding the first question, this part was deleted from the manuscript, so further discussion is not necessary.

Regarding Ismaili and Bokonjić [now 55], we agree that the increased MMP-9 levels cannot be interpreted as direct evidence of reparative remodeling. We have explicitly characterized this interpretation as hypothetical and emphasized that the lack of MMP-9 activity measurements, limited follow-up, and incomplete characterization of between-group effects prevent a definitive mechanistic conclusion.

Similarly, regarding Misra et al. [now 57], we clarified that increased OPG levels alone do not establish a change in the RANKL/OPG ratio or demonstrate reduced osteoclast activity, particularly because RANKL was not measured. The interpretation was therefore restricted to the observed biomarker changes and clinical outcomes.

9. Refocus the discussion and clarify the review’s added contribution.

The background sections on periodontal pathogenesis, general MMP biology, and other dental applications of PBM are extensive relative to the focused clinical synthesis. Please reduce repetition and retain the background most directly relevant to PBM-associated MMP/TIMP outcomes.

A dedicated integrative discussion should explain what this review adds beyond the existing reviews already cited. It should compare findings by biomarker, intervention classification, surgical versus nonsurgical treatment, assay type, and follow-up duration.

The title gives substantial prominence to TIMPs and extracellular matrix remodeling, whereas direct clinical evidence for TIMP modulation is sparse. Please clarify whether the manuscript primarily evaluates demonstrated molecular effects or critically examines a proposed therapeutic mechanism. The title, stated objective, and conclusions should consistently reflect that distinction.

Reply

We believe that all sections preceding the analysis of the clinical studies are necessary to provide the scientific background for understanding the relationship between established knowledge and the findings reported in clinical investigations. Nevertheless, we acknowledge that some of these sections may have been somewhat extensive. We have therefore shortened and revised them, particularly the section entitled Pathogenesis of Periodontitis. The shortened and reformulated text is highlighted in blue, whereas deletions in other sections remain indicated by strikethrough, and newly added text is highlighted in red.

We would particularly like to emphasize that our review is original and that neither of the cited reviews describes the effect of PBM on MMP/TIMP in periodontitis. This is clearly stated at multiple places in the revised manuscript.  Akram et al. (2016) evaluated a broad range of inflammatory biomarkers following heterogeneous laser therapies and antimicrobial photodynamic therapy. Importantly, only two of the ten primary clinical publications included in our review were covered. Other published reviews (refs. 6, 7, 46, 67) have predominantly evaluated the clinical effectiveness of PBM or broader laser-based periodontal therapies rather than specifically integrating MMP/TIMP biomarker findings with clinical outcomes and mechanistic considerations.

The original contribution of our review therefore lies in its focused critical synthesis of clinical MMP/TIMP-related evidence, including assessment of PBM intervention classification and dosimetry, biomarker methodology, periodontal treatment context, and the distinction between demonstrated clinical effects and proposed biological mechanisms. This contribution has now been explicitly emphasized in the revised manuscript.

Although we recognize that there is little direct clinical evidence for TIMP modulation and extracellular matrix remodeling relative to the title and scope, However, these processes are important to the biological rationale of the review. The objective of this work is not to describe MMP/TIMP regulation or periodontal regeneration as clinically proven effects of PBM, but to critically discuss these pathways as possible therapeutic targets and to evaluate the extent to which available clinical evidence supports their modulation. For these reasons, we consider that the original title is justified.

10. Revise the limitations and conclusion for precision.

The limitations section should address selection and language restrictions, study-level risk of bias, small samples, imprecision, possible publication bias, uncertain intervention classification, potential cohort overlap, and limited direct evidence for TIMPs. Heterogeneity is relevant, but it should not be presented as the sole explanation for uncertainty.

The conclusion states that clinical improvements occurred “without corresponding increases in MMP or TIMP levels.” This wording does not accurately summarize the central finding. The relevant issue is that clinical improvement was not consistently accompanied by additional PBM-associated biomarker changes, particularly reductions in MMPs.

Please distinguish insufficient evidence of an additional effect from evidence that no additional effect exists. The final conclusion should remain limited to what the available comparative studies establish.

Reply

We agree that the limitations of the available evidence extend beyond clinical and methodological heterogeneity and should be more comprehensively acknowledged. Accordingly, we have expanded the Limitations of the Review section to address English-language and publication restrictions, potential selection and publication biases, small sample sizes, methodological weaknesses of the original studies, incomplete reporting of between-group effect estimates and confidence intervals, possible unit-of-analysis limitations, uncertainty in PBM intervention classification, and the possibility of overlapping patient cohorts in the two Sopi publications. We have also emphasized the particularly limited direct clinical evidence regarding TIMP modulation. Although the original studies were critically evaluated, we clarified that no formal risk-of-bias assessment was performed.

We have also revised the Conclusion to distinguish clinical improvements observed after periodontal treatment from additional PBM-associated changes in MMP/TIMP biomarkers. In particular, the previous wording has been replaced to avoid suggesting that clinical improvements were generally unaccompanied by biomarker changes.

Finally, we have explicitly clarified that the absence of consistent evidence demonstrating additional PBM-related biochemical effects should not be interpreted as proof that such effects do not exist. The revised conclusion is therefore restricted to what can reasonably be established from the available comparative clinical studies.

We believe that these revisions provide a more balanced assessment of the strengths and limitations of the existing evidence and improve the precision of the manuscript's final conclusions.

 

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

The manuscript has develpped. A couple of minor issues require attention:

1. Table 1 and the narrative still include Sayar et al., which makes 11 primary studies . Lines 818–825 list Sayar [65] among the excluded studies, and MMP-13 has been dropped from the Abstract and Conclusion. You apparently meant to exclude Sayar but left it in the table and text.
2. Methods now state that animal and in vitro studies were excluded from the clinical synthesis and used only for mechanistic discussion. There is still no section on preclinical PBM→MMP/TIMP data. Section 6 still asserts PBM may “improve the MMP/TIMP balance,” and its citations [6,7,8,53] now point to Qadri 2007 (see the renumbering problembelow).
3. Several reference numbers still point to references that were dropped or shifted: [18] is now Zhao (NLRP3) but is cited for dentin MMPs (line 336), MMP-8 effects (line 389) and GCF sampling (line 492). [28] is now Behm (orthodontic tooth movement) but is cited at lines 389 and 492. Sayar is cited as [62], the same number as Akram, but the reference list has Sayar as [65]. “Recent meta-analyses…” (lines 401–403) still cites [21], which is a narrative review. A full doucble check is needed in for the refernces.

Author Response

General Response to the Reviewer

We would like to clarify that, in the previous revised version, we intentionally retained certain deleted passages in strikethrough to help the reviewer identify the changes made in response to the earlier comments. In sections requiring more extensive revision, however, we presented only the fully revised text. The strikethrough formatting may not have been properly recognized during document processing, causing some deleted passages to be interpreted as part of the final manuscript.

We have now removed all strikethrough text and prepared a clean version of the manuscript. During our final verification, we also identified several minor inconsistencies, which we have now corrected.

We believe that these corrections (marked in green) resolve the remaining concerns without affecting the methodology, interpretation of the clinical evidence, or conclusions of the review.

1. Table 1 and the narrative still include Sayar et al., which makes 11 primary studies . Lines 818–825 list Sayar [65] among the excluded studies, and MMP-13 has been dropped from the Abstract and Conclusion. You apparently meant to exclude Sayar but left it in the table and text.

Response: The apparent inconsistency resulted from the retention of strikethrough text in the previous version, as explained in our General Response. In the clean manuscript, Sayar et al. is excluded from Table 1 and the primary clinical synthesis and is mentioned only among the studies excluded on methodological grounds. Consequently, MMP-13 was not included among the biomarkers evaluated in the clinical synthesis, since the study by Sayar et al., which investigated this marker, had already been excluded. Accordingly, MMP-13 was also removed from the Abstract and Conclusion when summarizing the clinical evidence. The final synthesis consistently includes ten primary clinical studies and one systematic review considered separately as secondary evidence. No further changes to the manuscript were necessary regarding this point.

2. Methods now state that animal and in vitro studies were excluded from the clinical synthesis and used only for mechanistic discussion. There is still no section on preclinical PBM→MMP/TIMP data. Section 6 still asserts PBM may “improve the MMP/TIMP balance,”and its citations [6,7,8,53] now point to Qadri 2007 (see the renumbering problembelow).

Response: We clarify that the primary objective of our narrative review was to critically evaluate the available clinical evidence on the effects of PBM on MMPs and TIMPs in periodontitis, rather than to provide a comprehensive analysis of preclinical studies.

Importantly, our literature search did not identify animal studies directly investigating PBM-induced MMP/TIMP responses in experimental periodontitis. Most relevant preclinical studies on these biomarkers in response to PBM were conducted in other experimental settings, particularly orthodontic tooth movement (OTM), and therefore were not directly applicable to the present review. Studies on experimental periodontitis and PBM did not include MMPs/TIMPs. Therefore, the modified text is now as follows: Animal and in vitro studies were excluded, whereas selected experimental findings were considered only as background information on the general biological mechanisms of PBM, including their potential relevance to MMP/TIMP regulation (lines 115-117, marked in green).

 

As explained in our General Response, the paragraph containing the statement “improve the MMP/TIMP balance” and the corresponding citations [6,7,8,53] had already been deleted during the previous revision but was intentionally retained in strikethrough format to make the changes visible to the reviewer. This paragraph is not part of the final manuscript, and neither the statement nor the associated citations appears in Section 6 of the clean version.

Regarding the reference numbering, we confirm that Qadri et al. (2007) [53] is correctly included and discussed in the clinical evidence section, whereas Qadri et al. (2010) [64] is listed among the excluded studies because its intrapocket Nd laser protocol could not be reliably classified as PBM. Neither study is cited to support the mechanistic statement concerning the MMP/TIMP balance in Section 6 of the clean manuscript.

3. Several reference numbers still point to references that were dropped or shifted: [18] is now Zhao (NLRP3) but is cited for dentin MMPs (line 336), MMP-8 effects (line 389) and GCF sampling (line 492). [28] is now Behm (orthodontic tooth movement) but is cited at lines 389 and 492. Sayar is cited as [62], the same number as Akram, but the reference list has Sayar as [65]. “Recent meta-analyses…” (lines 401–403) still cites [21], which is a narrative review. A full doucble check is needed in for the refernces.

Response: As explained in our General Response, some of the apparent citation errors originated from previously deleted text that remained visible in strikethrough format. However, reference [18], which was renumbered during revision, was inadvertently retained in the paragraph concerning dentin MMPs. This citation has now been removed, while the two remaining references [22,23] have been retained (line 338).

We also acknowledge that reference [21] is a narrative review rather than a meta-analysis. We therefore corrected the wording from “Recent meta-analyses” to “A recent review ” (line 389).

The citations concerning Behm [28], Akram [62], and Sayar [65] are correctly assigned in the clean manuscript. We have additionally rechecked the reference numbering and citation consistency throughout the manuscript.

Reviewer 2 Report

Comments and Suggestions for Authors

Attached.

Comments for author File: Comments.pdf

Author Response

We thanks for final comments