Evaluation of Single-Shade Composite Resin Color Matching on Extracted Human Teeth.

Introduction: Universal single-shade composite resins are characterized by a property that enables the creation of restorations that mimic tooth structure to the extent possible with fewer shades of color. Objectives: This study aimed to instrumentally and visually evaluate the color correspondence of two single-shade composite resins in extracted human teeth multishade composite resins. Methods: Upper central incisors and upper and/or lower molars with intact buccal surfaces were selected. The study consisted of a control group (n = 20): Z250 XT (3M ESPE) (G1) multishade composite resin in colors A1 to A4, and a test group (n = 20) divided further into two equal groups, consisting of single-shade composite resin Omnichroma (Tokuyama Dental) (G2) and single-shade composite resin Vittra APS Unique from (FGM) (G3). Instrumental evaluation was performed using a spectrophotometer, and visual evaluation was performed by three observers. Descriptive measurements related to the differences in color obtained through instrumental means were analyzed using mean and standard deviation, wherein the means were compared using ANOVA, applying the Bonferroni post hoc test. Results: A statistically significant difference was observed among the groups (G1, G2, and G3) (ANOVA: p < 0.001). For the visual assessment, regardless of the assessment group, 77.49% of the teeth were within the acceptable color-match classification, with the single-shade resins showing better correspondence than the multishade resins. Conclusion: Single-shade composite resins showed different color-matching results when compared to multishade resins, both in spectrophotometry and visual evaluations. Clinical Significance. Single-shade composite resins simplify the shade-selection process and are promising materials for use in dental practice.

Do implant-retained mandibular overdentures maintain radiographic, functional, and patient-centered outcomes after 3 years of loading?

OBJECTIVES: Analyzing whether radiographic, functional, and oral health-related quality of life (OHRQoL) outcomes are maintained over 3 years of implant-retained mandibular overdenture (IMO) function and investigating the bite force associations in the 3rd year of function. MATERIAL AND METHODS: A longitudinal clinical study in which 24 IMO users were evaluated during a 3-year follow-up period. Patients' posterior area index, masticatory function, OHRQoL and bite force were assessed. The masticatory function parameter ST_X50 reflects the opening through which 50% of the crushed particles would pass, ST_B describes the homogeneity of the bolus, and the masticatory efficiency parameters ME_5.6 and ME_2.8 represent the % of material retained in the 5.6 and 2.8 mm sieves, respectively. RESULTS: A significant increase in posterior area index (p ≤ .01) was found in all evaluated periods. Minor deteriorations in ST_X50 (p ≤ .01) and ME_5.6 (p ≤ .01) between the 2nd and the 3rd year coincided with improvements in ST_B (p ≤ .01), number of cycles (p ≤ .01), and cycle time (p = .02). The global OHIP-Edent score (p = .02) and the scores in the functional limitation (p = .02), psychological discomfort (p ≤ .01), and handicap domains (p ≤ .01) increased significantly between the 2nd and the 3rd year. Correlations between bite force and cycle time (p = .03) and between posterior area index and ST_X50 (p ≤ .01) and ME_2.8 (p = .02) were also found. CONCLUSION: Changes in posterior area index, masticatory function, and OHRQoL are still ongoing during the 3rd year of IMO function. Bite force and posterior area index influence the masticatory function outcomes in the 3rd year of IMO function.

Relationship Between Masticatory Function Impairment and Oral Health-Related Quality of Life of Edentulous Patients: An Interventional Study.

PURPOSE: To investigate the influence of impaired masticatory function on the oral health-related quality of life of conventional complete denture wearers before and after the transition to implant-retained mandibular overdentures. MATERIALS AND METHODS: Masticatory function and oral health-related quality of life were evaluated in 40 edentulous patients after 3 months of adaptation to complete dentures and after transition to implant-retained mandibular overdentures. Masticatory function was evaluated through the swallowing threshold test with a standardized portion of an artificial test food (Optocal) to determine median particle size (×50) and homogenization index (B). After the test, the masticatory function outcomes were used to categorize patients in 2 groups according to chewing performance: (i) satisfactory or (ii) unsatisfactory. The cutoff value for ×50 was based on a preestablished value of 3.68 mm, whereas for the B index, median values were adopted for categorization. The oral health-related quality of life was analyzed via the Oral Health Impact Profile for Edentulous Adults (OHIP-EDENT) questionnaire. The Mann-Whitney test was used to compare masticatory function outcomes and OHIP-EDENT scores, and associations were checked using the Spearman correlation test and multiple linear regression. RESULTS: Masticatory function was significantly correlated with functional limitation (p = 0.02) and physical disability (p = 0.04) for complete denture wearers with unsatisfactory masticatory function. After the transition to implant-retained mandibular overdentures, only the psychological discomfort domain (p = 0.02) was influenced by the masticatory function category. Multiple linear regression analysis revealed that only the functional limitation domain (p < 0.001) of the complete denture wearers was associated with masticatory function outcomes. CONCLUSIONS: Implant-retained mandibular overdentures eliminate the problems that lead to functional limitations, consequently improving masticatory function and oral health-related quality of life of these individuals; however, patients with unsatisfactory masticatory function after transition to implant-retained mandibular overdentures still experience more psychological discomfort.

Impact of using magnifying dental loupes on clinical performance during tooth preparation: A systematic review.

Background: To assess whether using magnification loupes affects tooth preparation working posture performed by undergraduate students and dentistry professionals and whether it influences the quality of the preparation, operator satisfaction and procedure time. Material and Methods: This review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and registered in the International Prospective Register of Systematic Review (CRD42023482377). Electronic searches were conducted in PubMed/Medline, Cochrane Library, Web of Science, and Scopus databases for relevant articles published up to August 2023. Clinical or laboratory studies evaluating cavities or dental preparations performed with and without magnification loupes were considered eligible. The outcomes were operator working posture, dental preparation quality, operator satisfaction, and procedure time. The quality of the studies was evaluated using the JBI Critical Appraisal tools for Quasi-Experimental Studies. Results: The searches retrieved 1493 articles. Based on the eligibility criteria, 11 laboratory studies were included, where 410 undergraduate and graduate dental students conducted dental preparations in 1851 dental specimens. Of the 11 selected studies, 6 evaluated the working posture, 6 assessed the quality of the dental preparations, 5 reported operator satisfaction, and 2 assessed procedure time. The results showed that magnifying loupes significantly improved operator working posture, but did not influence the quality of tooth preparations. Although satisfaction reports about experiences with magnifying loupes were favorable, no significant difference was found. Conclusions: Magnification loupes improved operator working posture. However, clinical studies with more scientific evidence are needed for steady conclusions regarding operator satisfaction and procedural time. Key words:Magnification, dental loupes, tooth preparation, cavity preparation, dental education.

Assessment of Surface Roughness, Color, and Bonding Efficacy: Self-Adhesive vs. Conventional Flowable Resin.

This in vitro study aimed to analyze the surface roughness (Ra) and color stability (ΔEab, ΔE00) following simulated mechanical brushing and to evaluate the microtensile (µTBS) of self-adhering resin flowable (SARF) to dentin. The selected materials were Constic, Yflow AS, and Tetric N flow (TNF/control). Thirty composite resin cylinders were fabricated for surface property evaluation. Ra and color were assessed both before and after simulated brushing. The thresholds of 50:50% perceptibility and acceptability of color differences in the evaluated resins were assessed. For µTBS analysis, fifteen molars were selected, sectioned to expose flat dentin surfaces, and restored according to the manufacturers' instructions for microtensile testing. There were statistically significant differences in Ra among the groups, with Constic exhibiting the highest Ra value (0.702 µm; p < 0.05), whereas Yflow AS presented the lowest Ra value (0.184 µm). No statistically significant difference in color was observed among the groups (p > 0.05). The 50:50% perceptibility and acceptability thresholds were set at 1.2 and 2.7 for ΔEab and 0.8 and 1.8 for ΔE 00. All the results fell within the acceptable limits. The mean µTBS values of Constic, Yflow AS, and TNF were 10.649 MPa, 8.170 MPa, and 33.669 MPa, respectively. This study revealed increased Ra and comparable color stability among all the tested composite resins after abrasion. However, the SARF exhibited lower µTBS compared to conventional using an adhesive system.

Color Stability of Single-Shade Resin Composites in Direct Restorations: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

The objective was to compare the color match and color stability behavior of single- and multi-shade resin-based composites (RBCs) used for direct restorations. This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomized clinical trials evaluating the shade performance of single-shade RBCs in direct restorations were included. A search of the scientific literature was performed in five databases (April 2024). The meta-analysis was performed using RevMan 5.4, calculating the risk difference (RD) and 95% confidence interval (CI) of the dichotomous outcome using a random effects model. Bias was assessed using the RoB 2.0 tool, and certainty of evidence was assessed using the GRADEpro tool. Four studies were selected, with 263 restorations analyzed. The results showed comparable performance between single-shade RBCs and multi-shade RBCs in terms of color match and color stability over 12 months. Three studies had a low risk of bias with all expected results, and one study had some concerns. The certainty of evidence for color stability was considered low for all follow-up periods due to the small number of events and sample size. According to the United States Public Health Service Evaluation (USPHS) and the World Dental Federation (FDI), there is comparable clinical color performance between single-shade and multi-shade RBCs over 12 months.

Effect of Rapid High-Intensity Light-Curing on Increasing Transdentinal Temperature and Cell Viability: An In Vitro Study.

BACKGROUND: This study investigated effects of rapid high-intensity light-curing (3 s) on increasing transdentinal temperature and cell viability. METHODS: A total of 40 dentin discs (0.5 mm) obtained from human molars were prepared, included in artificial pulp chambers (4.5 × 5 mm), and subjected to four light-curing protocols (n = 5), with a Valo Grand light curing unit: (i) 10 s protocol with a moderate intensity of 1000 mW/cm2 (Valo-10 s); (ii) 3 s protocol with a high intensity of 3200 mW/cm2 (Valo-3 s); (iii) adhesive system + Filtek Bulk-Fill Flow bulk-fill composite resin in 10 s (FBF-10 s); (iv) adhesive system + Tetric PowerFlow bulk-fill composite resin in 3 s (TPF-3 s). Transdentinal temperature changes were recorded with a type K thermocouple. Cell viability was assessed using the MTT assay. Data were analyzed using one-way ANOVA and Tukey tests for comparison between experimental groups (p < 0.05). RESULTS: The 3 s high-intensity light-curing protocol generated a higher temperature than the 10 s moderate-intensity standard (p < 0.001). The Valo-10 s and Valo-3 s groups demonstrated greater cell viability than the FBF-10s and TPF-3 s groups and statistical differences were observed between the Valo-3 s and FBF-10 s groups (p = 0.023) and Valo-3 s and TPF-3 s (p = 0.025), with a potential cytotoxic effect for the FBF-10 s and TPF-3 s groups. CONCLUSIONS: The 3 s rapid high-intensity light-curing protocol of bulk-fill composite resins caused a temperature increase greater than 10 s and showed cell viability similar to and comparable to the standard protocol.

Effect of ultra-fast high-intensity light-curing on the properties of a new bulk-fill restorative resin composite system: A Scoping Review.

Background: This scoping review aims to analyze the impact of rapid high-intensity light-curing on a new bulk-fill resin-based composites (RBCs) designed for this type of polymerization. Material and Methods: This scoping review was reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) and Joanna Briggs Institute Manual of Evidence Synthesis. The methods were registered on the Open Science Framework (). The literature search was conducted in PubMed/MEDLINE, Embase, Web of Science, Scopus and Cochrane Library databases. Eligibility was considered for in vitro and clinical studies evaluating the effects of ultra-fast high-intensity light-curing on a new system of bulk-fill RBCs. Results: Of 1.688 articles identified, 27 were included in the qualitative synthesis. All studies were conducted in vitro. A total of 2.432 specimens were evaluated. The studies have shown that shortness light-curing may result in similar properties (stress generated by polymerization shrinkage, marginal integrity, and bond strength to dental interface) for the new bulk-fill RBCs. Conclusions: Therefore, the new bulk-fill RBCs can be light-cured with a short exposure time and high intensity, providing a time-saving benefit in clinical practice, with similar results to standard light-curing in conventional composites, although, its use should be approached with caution in the flowable composite. Key words:Resin composites, polymerization, dental materials, review.

Clinical Versatility of the Facility-Equator Implant System as Mandibular Overdenture Retainers.

The use of mandibular overdentures (MO) for the rehabilitation of totally edentulous individuals with limited bone availability is widespread and has proven clinical success. Narrow diameter implants (NDI) are available on the market as MO retainers to solve problems related to limited bone availability and bone thickness, providing a low-cost, minimally invasive treatment option. This technique evolved over the years, and changes frequently involved the number of implants used as MO retainers, as the adoption of a smaller number of implants can generate biomechanical disadvantages, contributing to the increased stress in peri-implant tissues, which may accelerate marginal bone loss (MBL), in addition to reducing masticatory capacity and satisfaction with rehabilitation. Some studies pointed out that the use of 3 or more implants as MO retainers improves the biomechanics. Thus, the objective of this study was to report 3 different clinical cases where 3 or more NDI were adopted to retain mandibular overdentures in association with diverse loading protocols: (i) 3 implants adopting conventional loading, (ii) 4 implants using progressive loading, and (iii) 4 implants with hybrid loading. The case with 4 implants and progressive loading showed a slight worsening of masticatory function at 1 year, in addition to a more pronounced MBL compared to other cases, but with improvements in satisfaction and oral health-related quality of life. Thus, NDI can be used as MO retainers with predictability and clinical success, using different numbers of implants and loading protocols.