Randomized prospective clinical trial of class II restorations using flowable bulk-fill resin composites: 4-year follow-up

Investigating the Effect of Polyetheretherketone (PEEK) Veneers on Bond Strength and Discoloration When Repairing Various Composites

OBJECTIVES

This study aimed to examine the impact of the strength and color change of composite materials that could be utilized in the repair of polyetheretherketone (PEEK) veneer fractures.

METHODS

The 220 nanoceramic-filled PEEK specimens used in the study were divided into four groups, and color measurements were made on a gray background (n=55): Group N, 1-mm-thick monochromatic composite; Group NN, 2-mm-thick monochromatic composite; Group F, 1-mm-thick 2-mm-diameter short fiber-reinforced composite, placed in the center and polymerized; and Group FF, 2-mm-thick 2-mm-diameter short fiber-reinforced composite, placed in the center and polymerized. The remaining mating surfaces were restored by filling with monochromatic composite and adhesion strength testing by re-measuring the color.

RESULTS

The results of the two-way ANOVA indicated that there was a significant color change caused by both thickness and composite type (p<0.001). Additionally, a significant difference in bond strength was observed between the groups.

CONCLUSION

In PEEK restorations, short fiber-reinforced composites significantly increase bond strength, while the use of monochromatic composites of a certain thickness ensures that color change remains within acceptable limits.

SIGNIFICANCE

 Although PEEK has a superior mechanical structure, it does not meet the aesthetic expectations and needs to be veneered. However, fractures are frequently seen due to low bond strength. Therefore, this study is important because it aims to provide guidance to clinicians on aesthetic and mechanical methods that can be used in PEEK prosthesis repair.

Clinical Outcomes of Bulk-Fill Resin Composite Restorations: A 10-Year Mapping Review and Evidence Gap Map

OBJECTIVE

To map the evidence regarding the clinical performance of posterior restorations with bulk-fill resin composites and identify research gaps.

MATERIALS AND METHODS

This mapping review was conducted following PRISMA-ScR guidelines for scoping reviews, and its protocol was registered on the Open Science Framework platform. Systematic searches were conducted, considering studies published between 2013 and February 2024 in the PubMed, Embase, and Cochrane databases. Clinical studies investigating the performance of bulk-fill resin composite restorations in class I and/or class II preparations with increments of 4 to 5 mm were included.

RESULTS

A total of 147 articles were identified, and based on the eligibility criteria, 26 studies were selected for descriptive analysis. Of the reviewed studies, 73% (n = 19) investigated high-viscosity bulk-fill composites, while 30% (n = 8) focused on low-viscosity bulk-fill composites. Evaluation periods ranged from 1 week to 10 years. Reported annual failure rates varied from 0% to 3%, with survival rates between 78.9% and 100%.

CONCLUSIONS

Bulk-fill resin composites of high viscosity were the most analyzed in the published studies, with evaluation periods of up to 10 years. The review of available scientific evidence showed clinically acceptable performance for composite bulk-fill restorations, with high survival rates and minimal annual failure rates. There is a need for long-term clinical studies on bulk-fill resin composites.

CLINICAL SIGNIFICANCE

This review demonstrates that both high and low-viscosity bulk-fill resin composites exhibit satisfactory clinical performance, which can help clinicians optimize chairside time. However, it is important to highlight the need for further studies with longer follow-up periods.

Flowable bulk-fill versus layering restorative material on Class II restorations: A randomized clinical trial

OBJECTIVE

This study evaluated the clinical performance of Class II restorations made with flowable bulk-fill base versus conventional layering ORMOCER-based restorative material in a split-mouth randomized clinical trial.

METHODS

Thirty patients received two class II restorations (n = 60) performed with different strategies. All preparations received the application of the universal self-etching adhesive system according to the manufacturer's recommendation, followed by the placement of a sectional matrix, wooden wedge, and separation ring. The first restoration was performed using 4 mm of flowable bulk-fill material covered by 2 mm of conventional viscosity restorative material (Bulk-fill technique). The second restoration was performed only with the conventional viscosity material, with a maximum of 2 mm thick increments, up to fill the cavity (Layering technique). After occlusal adjustment, the same polishing system was used for all restorations. Evaluations using the FDI criteria were conducted after 7 days, 12, and 24 months. Data were analyzed with the Fisher's Exact test (α=0.05).

RESULTS

From 30 participants, 24 attended the 24-month recall, and 48 restorations were evaluated. All restorations received acceptable overall scores for esthetic and biological properties after this period, while only 6.66 % of the restorations exhibited unacceptable overall scores for the functional properties in both groups. No significant differences between the tested restorative materials and techniques were found for each FDI criterion assessed. The success rate after 2 years was 93.33 % for both groups.

CONCLUSION

Both restorative materials exhibited good clinical performance for the parameters analyzed with no differences between them after 24-month follow-up.

CLINICAL RELEVANCE

Flowable bulk-fill ORMOCER-based material is a suitable alternative for direct Class II restorations, providing good clinical outcomes and simplifying the restorative procedure.

CLINICAL TRIAL REGISTRATION NUMBER

RBR-6mvp9w.

Clinical performance of different bulk-fill composite resin systems in class II cavities: A 2-year randomized clinical trial

OBJECTIVES

This study evaluated the clinical performance of bulk-fill resin composite systems with different viscosities in class II cavities.

MATERIALS AND METHODS

A total of 80 class II restorations were performed with a single operator in 50 patients using four different bulk-fill resin composite materials: Filtek™ Bulk Fill, Heated Filtek™ Bulk Fill, G-ænial™ BULK Injectable, and SonicFill3. A double-blinded randomized clinical trial was designed to evaluate the two-year clinical performance of the four bulk-fill composite resins using modified FDI criteria. Data were analyzed descriptively. Level of significance was set at 0.05. Differences between groups were tested using Wilcoxon-signed-rank and Mann-Whitney-U test as nonparametric tests.

RESULTS

Data were analyzed using Kruskal-Wallis, Mann-Whitney U, and Wilcoxon signed rank tests (p < 0.05). Eighty restorations were available for evaluation, with a survival function of 100%. No statistically significant differences were observed between the four groups regarding assessing esthetic, functional, and biological properties during different follow-up periods.

CONCLUSIONS

After 2 years of clinical follow-up, the bulk-fill composite systems with different viscosities seem to be esthetically, functionally, and biologically acceptable, with a promising clinical performance in class II cavities.

Fatigue and marginal adaptation of bulk fill restoratives: Effect of the layering technique and cavity dimension of extensively damaged teeth

OBJECTIVES

To evaluate the effect of layering technique and cavity dimension on the fatigue behavior and marginal adaptation of bulk fill (BF) restorations in extensively damaged teeth.

METHODS

Seventy-two premolars received class II cavities (MOD) followed by endodontic treatment. Half sample had 1/3 of their palatal cusp removed. Teeth were restored using three techniques: (I) incremental, with conventional resin composite (RC); (C) combined, using BF flow and RC, (B) bulk fill, with regular BF. Specimens were subjected to fatigue (80 N, 2 Hz, 37° C water) for 1 million cycles (n = 12). The test was interrupted every 250,000 cycles to evaluate tooth integrity, restoration fracture and adaptation using FDI criteria. Images of the proximal surfaces were obtained before and after the cycling to measure the gap. Restoration fatigue survival and success were analyzed using Weibull distribution and Maximum Likelihood Estimation. Gap thickness was analyzed with Kruskal-Wallis and Student-Newman-Keuls tests (α = 0.05).

RESULTS

For the survival analysis, Weibull modulus (β) and characteristic lifetime (η) were similar among groups. Yet, for the success analysis, in which only restorations that were free of technical complications were ranked as success, the bulk-fill technique resulted in higher β, while the combined technique produced restorations with higher η, for teeth that had their cusp removed. C-technique also resulted in smaller gaps than I and B.

SIGNIFICANCE

The effect of the layering technique on the success of restorations was dependent on the cavity extension. The combined technique favors the adaptation and the longevity of extensively damaged teeth.

A comparative assessment of color stability among various commercial resin composites

OBJECTIVES

The aim was to evaluate the color stability of six commercial restorative resin composites after being exposed to commonly consumed beverages. Repolishing impact on the stained composite was also assessed.

METHODS

One-hundred and fifty disc specimens (8 mm diameter & 3 mm thickness) were prepared from Filtek™ Universal Restorative, SDR flow+, everX Flow, G-ænial A'CHORD, G-ænial Universal Flo and G-ænial Universal Injectable. To assess the color stability in five various beverages, 25 specimens from each material were randomly distributed into five groups (n = 5), according to the utilized staining solution. Group 1: distilled water, Group 2: coffee, Group 3: red wine, Group 4: energy drink, Group 5: coke. The color changes (∆E) for all materials were measured using spectrophotometer at the baseline, after 84 days of staining and after repolishing. Data was collected and analyzed using ANOVA (α = 0.05).

RESULTS

Both material type and staining solution had a significant effect on the color stability of specimens (p < 0.05). Compared to other beverages, the color value of the specimens submerged in coffee and wine showed the most statistically significant (p < 0.05) mean ∆E. SDR flow + in coffee and wine presented the highest ∆E when compared to other tested materials (p < 0.05). After staining of the composites, repolishing was successful in lowering the ∆E value.

CONCLUSIONS

All the beverages had an impact on the color stability of the tested resin composites, with coffee and wine demonstrating the most significant effects. The variations in color stability varied depending on the specific material utilized. Dentists should possess awareness regarding the chemical interactions that occur between different beverages and various types of resin composites. Additionally, repolishing serves as an effective technique for eliminating surface discoloration in composite restorations.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2022 dental literature to briefly touch on several topics of interest to modern restorative dentistry. Each committee member brings discipline-specific expertise in their subject areas that include (in order of the appearance in this report): prosthodontics; periodontics, alveolar bone, and peri-implant tissues; dental materials and therapeutics; occlusion and temporomandibular disorders; sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence the daily dental treatment decisions of the reader with an emphasis on innovations, new materials and processes, and future trends in dentistry. With the tremendous volume of literature published daily in dentistry and related disciplines, this review cannot be comprehensive. Instead, its purpose is to update interested readers and provide valuable resource material for those willing to subsequently pursue greater detail on their own. Our intent remains to assist colleagues in navigating the tremendous volume of newly minted information produced annually. Finally, we hope that readers find this work helpful in managing patients.

The clinical performance of bulk-fill versus the incremental layered application of direct resin composite restorations: a systematic review

OBJECTIVES

To systematically review the scientific evidence comparing the clinical effectiveness of bulk-fill versus incrementally layered conventional resin composites and to evaluate if one method offers clear merits with specific clinical outcomes.

MATERIALS AND METHODS

Using relevant mesh terms and pre-established eligibility criteria in PubMed, Embase, Scopus and Web of Science, a thorough scientific search was conducted with an end-date of 30.04.2023. Randomized controlled clinical trials that involved the direct comparison of Class I and Class II resin composite restorations applied using incremental layering techniques versus bulk-filled in permanent teeth with an observation period of at least six months were considered. To evaluate the bias risk of the finalized records, a revised version of the Cochrane risk-of-bias tool for randomized trials was implemented.

RESULTS

Out of the 1445 records determined, 18 eligible reports were chosen for qualitative analysis. Data obtained was categorized as per, the cavity design, the intervention, the comparator(s), the methods of success/failure assessment, the outcomes, and follow-up. Two studies demonstrated an overall low-risk of bias, fourteen studies raised some concerns, and two studies exhibited high-risk.

CONCLUSION

Bulk filled resin composite restorations demonstrated clinical outcomes similar to those of incrementally layered resin composite restorations within a review interval of 6 months to 10 years.