Search Results (147)

This study examined the association between biofilm growth and surface properties of 3D printed, milled, and conventional materials used for manufacturing fixed dental prostheses. Disc-shaped specimens were produced and finished from five 3D-printing resins (VarseoSmile Crown plus [VSC], NextDent C&B MFH [ND], VarseoSmile Temp [VST], Temp PRINT [TP], P Pro Crown & Bridge [P]), two polymer milling blocks (composite: TetricCAD [TC], PMMA: TelioCAD [TEL]), two conventional polymer materials (Tetric EvoCeram [TEC], Protemp 4 [PT]), and zirconia (ZR). Surface roughness (R_a), wettability, interfacial tension (IFT) and surface topography were examined. Three-day biofilms were grown on the specimens using A. naeslundii, S. gordonii, S. mutans, S. oralis, and S. sanguinis in a multi-species suspension. Biofilms were quantified by crystal violet staining and with a plating and culture method (CFU/mL). Linear regression analysis was computed to demonstrate associations between the surface properties and biofilm growth. The strength of this relationship was quantified by calculating Spearman’s ρ. TC exhibited the highest, and TP the lowest IFT. TEC showed the highest R_a, while TEL had the lowest, with significant differences detected particularly between milled and 3D-printed specimens. TP specimens exhibited the highest biofilm mass, while ZR surfaces retained the least. Bacterial viability within the biofilms remained similar across all tested materials. There was a strong negative correlation between total IFT and biofilm mass, and a moderate positive correlation between R_a and CFU/mL. Surface properties are shaped by material composition, microstructure, and manufacturing methods and play a crucial role in biofilm formation on dental restorations. Full article

As a commonly used dental restorative material, light-cured composite resin exhibits mechanical properties that closely match those of natural tooth structure. In the process of biting, the filling material falls off severely due to fretting between the filling material and the fixed interface of the teeth, which shortens the life of the filling material. This study aimed to investigate the mechanisms and contributing factors of this phenomenon. In particular, this study investigated the friction and wear mechanisms at the tangential fretting interface between light-cured composite resin and the tooth substrate under varying fretting amplitudes, normal loads, and lubrication conditions. In artificial saliva, the friction coefficient increased with the fretting amplitude and decreased with the increase in the normal load. The result showed that when the fretting amplitude was large or the normal load was small, the fretting was always in the complete slip regime. When the fretting amplitude was small or the normal load was large, the fretting changed from the complete slip zone to the partial slip regime. The minimum friction coefficient in milk was 0.117, and the maximum friction coefficient in artificial saliva was 0.567. Coke and milk have little effect on the fixation of filling materials. Abrasive wear was the predominant mechanism, with small amplitudes or high loads leading to adhesive wear. The composite resin exhibited the least wear in cola and milk, while soda water and artificial saliva caused significantly greater damage. Full article

Background: Ameloblastomas account for roughly 1% of all jaw tumours and cysts, typically manifesting as slow-growing, painless swellings that expand both buccal and lingual cortical plates and may infiltrate adjacent soft tissue, often leading to a delayed diagnosis. These benign tumours, characterized by local invasiveness, originate from epithelial tissues and may develop from dental lamina cell rests, the enamel apparatus, the epithelial lining of odontogenic cysts, or basal epithelial cells of the oral mucosa. Methods: This paper aims to describe the comprehensive and interdisciplinary management of an extensive ameloblastoma in a 16-year-old patient, emphasizing the diagnostic challenges, surgical resection, reconstructive procedures, and subsequent oral rehabilitation. Results: At the eleven-year follow-up, clinical and radiographic examinations showed no signs of tumour recurrence. The patient presented no symptoms, indicating neither pain nor functional impairment. The prosthetic rehabilitation utilizing implant-supported fixed restorations was successfully completed, resulting in satisfactory masticatory function and aesthetics. This case adds to the existing evidence on the management of extensive ameloblastomas by demonstrating successful long-term outcomes following interdisciplinary surgical reconstruction and rehabilitation. Conclusions: The presented case highlights the complexity of restoring the lost tissues and functions, as well as the long-term clinical, functional, and aesthetic outcomes over an eleven-years follow-up period. Full article

Background/Objectives: The clinical application of CAD/CAM restorative materials continues to evolve due to increasing demand for aesthetic, durable, and minimally invasive indirect restorations. Hybrid nanoceramics, such as Grandio disc (VOCO GmbH, Cuxhaven, Germany), are increasingly used in indirect restorative dentistry due to their favourable combination of mechanical strength, polishability, wear resistance, and bonding potential. One challenge associated with adhesive protocols for CAD/CAM materials lies in achieving durable bonds with resin cements. Extensive post-polymerization during fabrication reduces the number of unreacted monomers available for chemical interaction, thereby limiting the effectiveness of traditional adhesive strategies and necessitating specific surface conditioning approaches. This study aimed to evaluate, in a preliminary, non-inferential manner, the influence of several combined conditioning protocols on surface micromorphology, elemental composition, and descriptive SBS trends of a CAD/CAM hybrid nanoceramic. This work was designed as a preliminary pilot feasibility study. Due to the limited number of specimens (two discs per protocol, each providing two independent enamel bonding measurements), all bond strength outcomes were interpreted descriptively, without inferential statistical testing. This in vitro study investigated the effects of various surface conditioning protocols on the adhesive performance of CAD/CAM hybrid nanoceramics (Grandio disc, VOCO GmbH, Cuxhaven, Germany) to dental enamel. Hydrofluoric acid (HF) etching was performed to improve adhesion to indirect resin-based materials using two commercially available gels: 9.5% Porcelain Etchant (Bisco, Inc., Schaumburg, IL, USA) and 4.5% IPS Ceramic Etching Gel (Ivoclar Vivadent, Schaan, Liechtenstein), in combination with airborne-particle abrasion (APA), silanization, and universal adhesive application. HF may selectively dissolve the inorganic phase, while APA increases surface texture and micromechanical retention. However, existing literature reports inconsistent results regarding the optimal conditioning method for hybrid composites and nanoceramics, and the relationship between micromorphology, elemental surface changes, and adhesion remains insufficiently clarified. Methods: A total of ten composite specimens were subjected to five conditioning protocols combining airborne-particle abrasion with varying hydrofluoric acid (HF) concentrations and etching times. Bonding was performed using a dual-cure resin cement (BiFix QM) and evaluated by shear bond strength (SBS) testing. Surface morphology was examined through environmental scanning electron microscopy (ESEM), and elemental composition was analyzed via energy-dispersive X-ray spectroscopy (EDS). Results: indicated that dual treatment with HF and sandblasting showed descriptively higher SBS, with values ranging from 5.01 to 6.14 MPa, compared to 1.85 MPa in the sandblasting-only group. ESEM revealed that higher HF concentrations (10%) created more porous and irregular surfaces, while EDS indicated an increased fluorine presence trend and silicon reduction, indicating deeper chemical activation. However, extending HF exposure beyond 20 s did not further improve bonding, suggesting the importance of protocol optimization. Conclusions: The preliminary observations suggest a synergistic effect of mechanical and chemical conditioning on hybrid ceramic adhesion, but values should be interpreted qualitatively due to the pilot nature of the study. Manufacturer-recommended air abrasion alone may provide limited adhesion under high-stress conditions, although this requires confirmation in studies with larger sample sizes and ageing simulations. Future studies should address long-term durability and extend the comparison to other hybrid CAD/CAM materials and to other etching protocols. Full article

Purpose: This in vitro study ascertained the impact of three distinct alumina particle sizes on the shear bond strength (SBS) between two distinct provisional crowns (milled and 3D-printed) and stainless-steel orthodontic brackets following artificial aging. Materials and methods: Eighty specimens [disc 10 mm diameter/15 mm height] were fabricated with two provisional crown materials, milled (CopraTemp) [group (GP) M] and three-dimensionally printed (Asiga DentaTooth) (GP P), and divided into eight subgroups based on alumina oxide (sandblasting) particle size surface treatments of 25 μm [P25, M25], 50 μm [P50, M50], and 100 μm [P100, M100], with no surface treatment specimens serving as control [PC, MC]. After thermocycling (2200 cycles), the SBS and Adhesive Remnant Index (ARI) were calculated. Statistical tests included one-way analysis of variance (ANOVA) (Kruskal–Wallis), followed by post hoc tests [Tukey HSD, Dunn’s], with the probability ‘p’ value being significant at 0.05 (p ≤ 0.05). Results: Without surface treatment, the 3D-printed provisional crown had the lowest SBS [median (IQR); 12.8 (2.74)]. The highest SBS was found in both milled and 3D-printed PMs with 50-micron particle sizes [Milled = 23.10 (2.3); Printed = 20.72 (2.31)], followed by 100-micron [Milled = 20 (2.36); Printed = 17.99 (3.45)] and 25-micron [Milled = 16.13 (2.71); Printed = 15.08 (1.55)]. The majority of cohesive failures were seen in the milled subgroups, while all subgroups of 3D-printed provisional material had adhesive bond failures. Conclusions: Sandblasting, irrespective of particle size, enhances SBS in both milled and 3D-printed provisional restorations; however, 50-micron alumina particles are recommended since they enhance SBS substantially. Full article

Background and Objectives: Cement-retained implant restorations are widely used because they offer favorable esthetics and a passive fit. Their long-term performance is strongly influenced by cement selection and surface conditioning. This study compared the clinical performance of a resin-modified glass ionomer cement (Fuji Plus^®) with a provisional acrylic-urethane cement (DentoTemp™) in partial implant restorations. Materials and Methods: A retrospective cohort of 40 patients with three-unit implant-supported fixed dental prostheses was followed for at least three years. Restorations were fabricated from zirconia or metal-ceramic frameworks and cemented with either Fuji Plus^® or DentoTemp™. Clinical outcomes included retention, failure events, marginal adaptation, and peri-implant tissue response. In order to illustrate the impact of cement type and abutment height, mechanical testing was also carried out on standardized in vitro models; however, these tests were not powered for formal hypothesis testing. Although OCT images were included in this study only as illustrative examples from our clinical database and were not obtained from the analyzed cohort, OCT may be a useful tool for non-invasive assessment of marginal fit. Results: Zirconia restorations showed a retention rate of 95 percent, while metal-ceramic restorations reached 85 percent. All four failures occurred in cases cemented with DentoTemp™, giving an overall retention rate of 80 percent for this group. Fuji Plus^® achieved complete retention in all cases. Re-cementation with Fuji Plus^® successfully resolved the failures. Marginal adaptation was evaluated qualitatively because radiographic analysis did not enable accurate measurement of marginal gaps. When cement remnants were found, mild peri-implant inflammation was seen. Conclusions: Within the limitations of this small retrospective, non-randomized cohort, Fuji Plus^® demonstrated a tendency toward better peri-implant tissue response and longer-term retention than DentoTemp™. These findings should be interpreted as preliminary and exploratory rather than conclusive. Fuji Plus^® may be a suitable option for definitive cementation in partial implant restorations, while DentoTemp™ may be considered in selected situations where retrievability is important. Full article

The purpose of this study was to evaluate the effect of different framework materials and thermal aging on the shear bond strength (SBS) of gingiva-colored composites used in fixed dental restorations. A total of 270 samples (10 × 10 × 2 mm³) were prepared using titanium, zirconia, and modified polyetheretherketone (modified PEEK). Three gingiva-colored composites (Gradia Gum, Anaxgum, Nexco) were applied after surface polishing and sandblasting. All specimens were stored in water at 37 °C for 24 h, then half of each group was subjected to thermal aging consisting of 10,000 cycles at temperatures between 5 and 55 °C. SBS testing was performed using a universal testing machine with a crosshead speed of 1 mm/min. Bonding failures were analyzed under a stereomicroscope, and one sample from each group was examined using a scanning electron microscope. SBS data were analyzed using three-way ANOVA with composite type, framework material, and thermal aging as factors, followed by pairwise comparisons (SPSS 23.0; p < 0.05). The highest SBS was recorded for the zirconia framework combined with Gradia Gum, specifically in the group without thermal aging (p < 0.05), while the lowest was observed for zirconia combined with Nexco after thermal aging (p < 0.05). Adhesive failures were predominant in the modified PEEK groups, whereas mixed failures occurred more frequently in titanium and zirconia groups. Both composite type and framework material significantly influenced SBS values, with thermal aging having a detrimental effect across all groups. This study demonstrates that both framework material and composite type affect bond strength, with specimens not subjected to thermal aging maintaining better adhesion. Thermal cycling reduced SBS in all groups, although the extent varied by material combination. Full article

Background/Objectives: Oral health is a critical component of public health, yet disparities in access and financing remain significant. In Bulgaria, dental services are financed through the National Health Insurance Fund and patient co-payments, with coverage differing between children and adults. The aim of this study was to analyze the dynamics of health insurance payments and expenditures for dental care in Bulgaria over the period 2019–2025, with a focus on differences between age groups and the balance between public funding and patient contributions. Methods: A retrospective descriptive–analytical study was conducted using aggregated data from NHIF annual reports, national legislation, and secondary literature. Absolute expenditures (BGN) and relative shares (%) of dental services within total health insurance payments were examined for the period 2019–2025 (actual data). Key dental procedures analyzed included examinations, restorations, extractions, and treatment of pulpitis/periodontitis in children, as well as prosthetic rehabilitation in older adults. Descriptive statistics, trend analysis, and simple linear regression were applied to assess expenditure growth and predictability. Results: Total health insurance payments in Bulgaria nearly doubled between 2019 and 2025, increasing from 4.12 to 8.87 million BGN. Dental expenditures rose from 167,000 to 416,000 BGN, with the share of dental care rising modestly from 4.05% to 4.69%. For children, NHIF covered nearly all costs, with minimal or absent co-payments. Among adults, a co-financing model prevailed, with fixed patient contributions for basic services but full NHIF coverage for prosthetic rehabilitation in edentulous patients aged 65–69 years. Conclusions: Bulgaria’s dental care financing reflects a socially oriented model, with full coverage for children and mixed financing for adults. Strategic policy adjustments are needed to ensure sustainability, equity, and alignment with universal health coverage goals. Full article

Background/Objectives: Artificial intelligence (AI) has been increasingly used to support radiological assessment in dentistry. We benchmarked machine learning (ML), deep learning (DL), and a hybrid optimization-assisted approach for the automatic five-class image-level classification of dental restorations (filling, implant, root canal treatment, fixed partial denture/bridge, crown) on panoramic radiographs. Methods: We analyzed 353 anonymized panoramic images comprising 2137 labeled restorations, acquired on the same device. Images were cropped and enhanced (histogram equalization and CLAHE), and texture features were extracted with GLCM. A three-stage pipeline was evaluated: (i) GLCM-based features classified by conventional ML and a baseline DL model; (ii) Hybrid Grey Wolf–Particle Swarm Optimization (HGWO-PSO) for feature selection followed by SVM; and (iii) a CNN trained end-to-end on raw images. Performance was assessed with an 80/20 per-patient split and 5-fold cross-validation on the training set. While each panoramic radiograph may contain multiple restorations, in this study we modeled the task as single-label, image-level classification (dominant restoration type) due to pipeline constraints; this choice is discussed as a limitation and motivates multi-label, localization-based approaches in future work. The CNN baseline was implemented in TensorFlow 2.12 (CUDA 11.8/cuDNN 8.9) and trained with Adam (learning rate 1 × 10⁻⁴), with a batch size 32 and up to 50 epochs with early stopping (patience 5); data augmentation included horizontal flips, ±10° rotations, and ±15% brightness variation. A post hoc power analysis (G*Power 3.1; α = 0.05, β = 0.2) confirmed sufficient sample size (n = 353, power > 0.84). Results: The HGWO-PSO + SVM configuration achieved the highest accuracy (73.15%), with macro-precision/recall/F1 = 0.728, outperforming the CNN (68.52% accuracy) and traditional ML models (SVM 67.89%; DT 59.09%; RF 58.33%; K-NN 53.70%). Conclusions: On this single-center dataset, the hybrid optimization-assisted classifier moderately improved detection performance over the baseline CNN and conventional ML. Given the dataset size and class imbalance, the proposed system should be interpreted as a decision-supportive tool to assist dentists rather than a stand-alone diagnostic system. Future work will target larger, multi-center datasets and stronger DL baselines to enhance generalizability and clinical utility. Full article

The field of dental restorations continues to demand durable prosthetic materials with a focus on esthetic appeal. This systematic review and meta-analysis compared the mechanical properties and bonding performance of computer-aided design (CAD)/computer-aided manufacturing (CAM)-milled and three-dimensionally (3D) printed zirconia fixed dental prostheses. A systematic search of major databases identified 15 eligible recent in vitro studies. Random-effects meta-analyses (based on standard mean deviation) and heterogeneity (I²) and sensitivity analyses were performed. The meta-analysis showed no significant differences between the groups in flexural strength, hardness, density, bond strength, and fracture toughness. However, heterogeneity remained high, reflecting possible differences in the build orientation, additive manufacturing technique, and sintering protocols. A qualitative analysis of the literature also revealed that milled zirconia was generally associated with greater consistency in strength, hardness, and accuracy. Three-dimensionally printed zirconia, while more variable due to porosity and processing factors, frequently reached clinically acceptable values, with certain orientations achieving flexural and bonding strengths equal to or surpassing those of milled zirconia. Both fabrication methods benefited from surface treatments, and artificial aging confirmed stability within functional ranges. Overall, CAD/CAM-milled zirconia remains the benchmark for predictability; however, advances in additive manufacturing suggest a growing potential for 3D-printed zirconia in complex restorations. Full article

Ceramic dental implants, particularly one-piece zirconia, offer a biocompatible and aesthetic alternative to titanium, with high strength and improved oral hygiene. By eliminating the implant–abutment micro-gap, they reduce bacterial accumulation because of their low plaque affinity and enhance stability. However, challenges remain, including alignment precision, limited retrievability, and sensitivity to mechanical stress. Misalignment can affect occlusal and functional outcomes, and zirconia’s rigidity complicates crown removal and modification. This case report explores the use of PEEK (polyether ether ketone) primary telescopic crowns to overcome these limitations, improving force distribution, enabling minor adjustments, and enhancing prosthetic retrievability in full-mouth zirconia restorations. A 62-year-old male patient seeking a fixed solution to replace removable dentures received 16 one-piece zirconia implants (eight per jaw). PEEK telescopic crowns were used over implant abutment copings, finalized with aesthetic zirconia bridges. The report details surgical and prosthetic procedures, along with a brief literature review on zirconia implants and PEEK applications. PEEK integration in telescopic prosthetic designs marks a notable advancement in prosthodontics. Its shock-absorbing, biocompatible, and stress-modulating properties make it valuable for implant-supported and hybrid restorations. As digital workflows advance, PEEK-based telescopic restorations may increasingly replace traditional metal-based solutions, improving long-term clinical outcomes. Further clinical research on a larger sample is needed. Full article

Background/Objectives: This retrospective study aimed at evaluating the clinical performance of non-engaging abutments in multi-unit implant-supported prostheses and assessing the influence of abutment combinations and clinical variables on biological and technical outcomes. Methods: Forty patients with 90 implants and 40 fixed dental prostheses were involved. The study population was divided into three groups: 17 patients (8 males, 9 females) in the first group, 16 patients (7 males, 9 females) in the second, and 7 patients (2 males, 5 females) in the third. All patients received multi-unit implant restorations in a private practice between January 2021 and December 2023, and each prosthesis was in function for one year after delivery, with a mean follow-up of 2.17 ± 0.32 years. Restorations involved non-engaging abutments alone or in combination with engaging abutments or multi-unit abutments. Clinical parameters included implant and prosthesis survival rates, probing pocket depth, bleeding on probing, marginal bone loss, and the prevalence of biological and technical complications. For the comparison between the three groups, the analysis of variance was used to compare group means. When appropriate, Tukey’s post hoc test was applied for multiple comparisons. The significance level was set at p < 0.05. Results: The implant and prosthesis survival rates were both 100%. Mean marginal bone loss was 0.53 ± 0.33 mm, and mean probing pocket depth was 4.2 ± 0.75 mm. No cases of peri-implantitis were observed. Mucositis prevalence was 11.11% at the implant level. No significant differences were found among different abutment combinations for biological outcomes or complications. The technical complication rate was 5%. Conclusions: Non-engaging abutments demonstrated favorable short-term clinical outcomes with minimal biological and technical complications. They may represent a reliable option for the restoration of multi-unit prostheses, although long-term studies are needed. Full article

Background/Purpose: Teeth prepared for fixed dental prostheses are subject to various types of insults in the oral cavity. Therefore, to protect the tooth, the pulp, and supporting structures, provisional restorations are mandatory. Our study aimed to evaluate the knowledge and clinical practices regarding provisional fixed dental prostheses (PFDPs) among dental professionals in Saudi Arabia. Materials and Methods: A cross-sectional study based on a self-administered online survey was conducted among 312 dentists (general practitioners and specialists) across Saudi Arabia. The questionnaire assessed participants’ knowledge (11 items) and clinical practices (9 items) related to PFDPs. Statistical analyses included descriptive statistics, chi-square tests, and multivariate logistic regression. Results: Only 46.5% of respondents demonstrated adequate knowledge of PFDPs. Knowledge was significantly higher among specialists than general practitioners (57.4% vs. 41.7%, p = 0.011), and specialists were more likely to recognize the influence of PFDPs on treatment outcomes. Clinical practice patterns indicated that even though 94.2% of respondents frequently placed PFDPs, only 66.0% always did so. Moreover, 21.2% of respondents rarely or never disinfect PFDPs. Public sector dentists and specialists were more likely to use custom-made PFDPs. Key gaps in knowledge were observed regarding the materials and equipment used in the fabrication of PFDPs, particularly concerning CAD/CAM technology. Conclusions: Although most dentists in Saudi Arabia provided PFDPs to their patients, significant gaps remain in their knowledge, particularly regarding fabrication materials and techniques. Targeted educational interventions, especially for general practitioners, are needed to enhance clinical outcomes. Full article

Objective: This study aimed to compare two protocols for immediate implants with fixed provisional restoration, no grafting (trimodal approach = TA) versus grafting in both the osseous gap and peri-implant mucosa (a trimodal approach with modification of the bony and mucosal compartments = TAOM), by measuring soft tissue changes over time. The periodontal phenotype was noted to investigate the relationship between its thickness and the clinical outcomes. Methods: Thirty-one patients met the inclusion criteria (15 in the TA group and 16 in the TAOM group). The TA group was a historical control group. Measurements were taken using a digital caliper at T0 and 3, 6, and 12 months following the procedure (T3), (T6), and (T12), respectively, from reference points marked in a dental-supported stent. The periodontal phenotype was determined using an analogical caliper. Results: T12: Vertical midfacial change was −0.17 ± 0.37 in the TAOM group and 0.54 ± 0.33 in the TA group, respectively. Statistical significance (p = 0.0001) was found. Papilla vertical change in the TAOM group was −0.16 ± 0.45 mesially and 0.00 ± 0.44 distally. In the TA group, it was 0.55 ± 0.82 mesially and 0.86 ± 0.95 distally. Statistical significance (p = 0.0001) was also found. Conclusions: There were differences in soft tissue change between the two groups, and changes were related to the periodontal phenotype. Studies with more extended follow-up periods are needed to assess the long-term evolution of both protocols. Full article

This narrative review addresses the complexities of managing the vertical dimension of occlusion (VDO) in restorative dentistry, focusing on predictability in prosthetic reconstructions. Altering VDO impacts biological, biomechanical, esthetic, and functional aspects, making it a controversial topic. While VDO naturally evolves throughout life, interventions require careful consideration due to potential complications. Various techniques guide VDO determination, including facial proportions, physiological methods, phonetics, and cephalometric analysis. Clinicians must understand these principles and adapt them to individual patient needs. Materials and Methods: A narrative literature review was conducted using PubMed, Scopus, Google Scholar, and the Cochrane Library, searching keywords like “vertical dimension of occlusion”, “dental”, “diagnosis”, “management” and “complications”. In addition to the literature review, two case reports with extensive prosthodontic restorations were included to illustrate the diagnostic challenges and treatment considerations in a clinical setting. Results: Increasing VDO aids restorative treatments, re-establishing morphology, and facilitating additive procedures. Minimally invasive approaches, provisional restorations, and fixed restorations with functional contours are favored. Individualized, patient-centered care is critical, recognizing unique anatomical and functional needs. This approach optimizes stomatognathic system rehabilitation while preventing adverse effects on body posture and airway dimensions. Conclusions: To ensure predictable results and minimize risks, changes in VDO should be kept to a minimum to achieve dentofacial aesthetic harmony and secure adequate space for the planned restorations The two case reports presented, with different clinical approaches, underline the importance of understanding the potential risks and benefits of VDO alteration which is crucial for achieving predictable and successful outcomes in complex restorative cases. Full article