Search Results (7)

Background/Objectives: The integrity of proximal contact and marginal adaptation in Class II composite restorations is essential for mechanical stability, interfacial integrity, and long-term clinical performance. These outcomes are strongly influenced by the matrix system used during restoration. This systematic review aimed to evaluate the performance of different matrix systems in restoring posterior proximal cavities, with a specific focus on their interaction with composite materials. Materials and Methods: A systematic literature search was performed in PubMed, Cochrane Library, ScienceDirect, and Scopus for studies published between 2014 and 2024. Clinical and in vitro studies comparing different matrix systems used in Class II posterior composite restorations were included. Sixteen studies met the eligibility criteria. Risk of bias was assessed using the RoB 2 tool for randomized clinical trials and the ROBINS-I tool for non-randomized studies. Results: Sectional matrix systems consistently demonstrated superior performance in achieving anatomically accurate and tight proximal contacts compared with circumferential and transparent matrix systems. Metal matrices generally showed better contact tightness and marginal adaptation than transparent matrices, likely due to their higher rigidity and improved resistance to deformation during composite placement and polymerization. The adjunctive use of separation rings and contact-forming instruments further enhanced proximal contact quality and marginal integrity. Regarding composite types, high-viscosity bulk-fill composites provided better marginal adaptation and proximal contact tightness than flowable bulk-fill and conventional composites. Conclusions: Within the limitations of the included studies, proximal contact quality and marginal adaptation in Class II composite restorations are influenced by the matrix system, composite material behavior, and clinical application protocol. Sectional metal matrix systems combined with separation rings appear to be associated with improved outcomes in the included studies, while auxiliary contact-forming instruments may further improve restorative outcomes. Full article

The aim of this study was to compare the interproximal contact tightness of lateral teeth after restoring adjacent proximal walls with four types of direct adherent biomaterials. Distal and mesial boxes were prepared on 160 artificial right first and second upper molars. Each set of 40 pairs of boxes was restored using one bulk biomaterial: Equia Forte Fil HT (GC), Cention^® Forte (IVOCLAR VIVADENT), Admira Fusion x-tra (VOCO), or 3M^TMFiltek^TM One Bulk Fill. The mean difference in the passing-through force varied from sound to restored surfaces immediately after application, as well as at 7 and 14 days after: Equia Forte Fil HT—4.07 ± 0.01, 4.08 ± 0.01, and 4.11 ± 0.01; Cention^® Forte—3.30 ± 0.01, 3.50 ± 0.01, and 3.56 ± 0.01; Admira Fusion x-tra—4.10 ± 0.01, 4.13 ± 0.01, and 4.13 ± 0.01; 3M^TMFiltek^TM One Bulk Fill—4.08 ± 0.01, 4.09 ± 0.01, and 4.07 ± 0.01 (p < 0.05). The passing-through force of the restored contact areas showed significantly higher values when compared to those for the sound surfaces, and among them, all biomaterials presented similar values, except for Cention^® Forte. The potential clinical relevance of this study relates to better knowing the most appropriate restorative material for large proximal caries on adjacent surfaces from the outset of the treatment protocol. Full article

Lower back pain (LBP) is one of the most prevalent health losses in adults worldwide. Historically, heat has been successfully used for treating pain and relieving tight muscles. Given the effective contact with the occupant’s back and proximity to the heat source, coupled with increasing commute times, automotive seats offer an opportunity to intervene. Fifteen adults (nine female) who experienced acute, subacute, and chronic lower back pain were recruited to examine the effectiveness of heat delivered to the lower back in providing temporary pain relief. Participants sat in a car seat for 38 min on two days, which included a 5-min baseline followed by a 33-min intervention; control, or localized. For the control condition, participants sat for 33 min without any thermal devices on, while the localized condition heated and maintained the seat surface temperature of the lower seat back area to ~45 °C. Over the 33-min control condition, the back skin temperature increased by ~1–2 °C and did not impact the subjective LBP. Heating the lower back for 33 min to ~39 °C reduced the subjective LBP by 10%. We demonstrated that lower back pain can be alleviated from an automotive seat providing heat to the lower back within normal commute times in those with lower back pain. Full article

The purpose of this study is to evaluate the influence of the matrix system on proximal contact tightness (PCT) of posterior composite resin restorations. Standardized class II cavities on 180 first lower molar dentiform model teeth (Frasaco GmbH, Tettnang, Germany) were prepared. Three groups were formed considering the matrix system: Group-IM: Ivory matrix (Hahnenkratt GmbH, Königsbach-Stein, Germany), Group-OM: Omni matrix (Ultradent, South Jordan, UT, USA), and Group-PM: Palodent V3 sectional matrix (Dentsply, Charlotte, NC, USA). Teeth were restored with resin composite mounted in a manikin head to simulate the clinical environment. Proximal contact tightness (PCT) was measured using a custom-made portable dental pressure meter (PDPM), and the validation of the PCT results was performed with a histogram analysis acquired from bite-wing radiography. All data were statistically analyzed by ANOVA and t-test in SPSS software (v.27.0) (p < 0.05). PM group showed statistically tighter contacts on both mesial (PCTm: 228.28 ± 59.17 N) and distal surfaces (PCTd: 254.91 ± 65.69 N) (p > 0.05). Mesial contacts were found to be significantly tighter than distal contacts among all (p < 0.05). According to the histogram results, only in the PM group, the difference between the mesial and distal areas is significant (p < 0.05). Histogram results confirmed that the tightest contact values were achieved in the PM group, followed by the OM and IM groups, respectively (p < 0.05). The use of sectional matrix systems and separation rings is more effective in creating tighter contact than conventional matrix systems. The use of anatomical wedges will help to create a more natural approximal contour and narrow contact area. Full article

This review addresses the rationale of recurrent and/or residual caries associated with resin composite restorations alongside current strategies and evidence-based recommendations to arrest residual caries and restrain recurrent caries. The PubMed and MEDLINE databases were searched for composite-associated recurrent/residual caries focusing on predisposing factors related to materials and operator’s skills; patient-related factors were out of scope. Recurrent caries and fractures are the main reasons for the failure of resin composites. Recurrent and residual caries are evaluated differently with no exact distinguishment, especially for wall lesions. Recurrent caries correlates to patient factors, the operator’s skills of cavity preparation, and material selection and insertion. Material-related factors are significant. Strong evidence validates the minimally invasive management of deep caries, with concerns regarding residual infected dentin. Promising technologies promote resin composites with antibacterial and remineralizing potentials. Insertion techniques influence adaptation, marginal seal, and proximal contact tightness. A reliable diagnostic method for recurrent or residual caries is urgently required. Ongoing endeavors cannot eliminate recurrent caries or precisely validate residual caries. The operator’s responsibility to precisely diagnose original caries and remaining tooth structure, consider oral environmental conditions, accurately prepare cavities, and select and apply restorative materials are integral aspects. Recurrent caries around composites requires a triad of attention where the operator’s skills are cornerstones. Full article

Patients still refuse or discontinue orthodontic treatment due to related pain and discomfort. In this study, we investigate if low-level laser therapy (LLLT) can reduce pain caused by orthodontic bands. Sixty subjects who needed bands placed on the upper permanent first molars were assigned randomly to the LLLT group, placebo, and control groups. Inclusion criteria were: age range 10–14 years, fully erupted upper first molars in healthy condition, presence of tight mesial proximal contact. Exclusion criteria were: systemic or metabolic diseases, chronic pain or neurological or psychiatric disorders, use of pharmacological agents interfering with pain perception, previous orthodontic treatment or the simultaneous presence of other devices in the patient’s mouth. The assessment of pain was performed by using a numeric rating scale (NRS) considering different time intervals, i.e., immediately after bands placement, 6 h, 24 h, and from day 2 to day 5. Differences in the maximum pain and in pain experienced at each time-point, among the three groups, was assessed by using the Kruskal–Wallis H. The final sample included 56 patients, 29 males, and 27 females, with a mean age of 12.03 ± 1.3 years. Patients were randomly allocated into three groups (tested, control, and placebo group) with each group consisting respectively of 19, 20, and 17 individuals. Subjects in the LLLT experienced less pain at each time interval as well as the maximum pain score being lower in the LLLT compared to control and placebo groups. These findings were all statistically significant (p < 0.05). LLLT can alleviate the intensity of pain after the placement of orthodontic bands. Full article

Cancer-induced pain occurs frequently in patients when tumors or their metastases grow in the proximity of nerves. Although this cancer-induced pain states poses an important therapeutical problem, the underlying pathomechanisms are not understood. Here, we implanted adenocarcinoma, fibrosarcoma and melanoma tumor cells in proximity of the sciatic nerve. All three tumor types caused mechanical hypersensitivity, thermal hyposensitivity and neuronal damage. Surprisingly the onset of the hypersensitivity was independent of physical contact of the nerve with the tumors and did not depend on infiltration of cancer cells in the sciatic nerve. However, macrophages and dendritic cells appeared on the outside of the sciatic nerves with the onset of the hypersensitivity. At the same time point downregulation of perineural tight junction proteins was observed, which was later followed by the appearance of microlesions. Fitting to the changes in the epi-/perineurium, a dramatic decrease of triglycerides and acylcarnitines in the sciatic nerves as well as an altered localization and appearance of epineural adipocytes was seen. In summary, the data show an inflammation at the sciatic nerves as well as an increased perineural and epineural permeability. Thus, interventions aiming to suppress inflammatory processes at the sciatic nerve or preserving peri- and epineural integrity may present new approaches for the treatment of tumor-induced pain. Full article