Effect of surface sealant on the surface roughness of different composites and evaluation of their microhardness

Influence of surface sealants on the quality of posterior restorations with bulk-fill composites: A 4-year randomized clinical trial

OBJECTIVES

The aim of this study was to evaluate the clinical performance of surface sealants associated with a bulk-fill composite in posterior restorations after 4 years.

METHODS

A total of 174 posterior restorations were performed on 57 participants using a self-etch adhesive system and a bulk-fill composite. The groups were then divided into the following categories: 1) without surface sealant (NoS), 2) with surface sealant Biscover (Bisco, SBi), and 3) with surface sealant Permaseal (Ultradent, SPe). Restorations were evaluated using FDI criteria at baseline and after 1 and 4 years. Statistical analysis was conducted using Kaplan-Meier survival analysis and the Chi-square test (α = 0.05).

RESULTS

After 4 years, only one restoration was lost (1 in the NoS group). The fracture/retention rate (with 95% confidence interval) was 98% for NoS and 100% for both SBi and SPe (p = 0.76). The majority of secondary outcomes showed minor defects, with no significant differences among the groups (p > 0.05). However, significant differences were observed among the groups in terms of marginal staining and marginal adaptation (p = 0.03). In both items, twelve restorations (nine in NoS, one in SBi, and two in SPe) showed minor marginal discrepancies favoring the sealant groups (SBi and SPe).

SIGNIFICANCE

Regardless of the use of surface sealants, the bulk-fill composite restorations showed excellent clinical performance after 4 years. However, the groups that received sealants showed better marginal adaptation and less marginal discoloration compared to those that did not receive sealants.

The Effect of Finishing and Polishing Systems on Surface Roughness and Microbial Adhesion of Bulk Fill Composites: A Systematic Review and Meta-Analysis

Objectives: This paper presents a systematic review and meta-analysis of the effect of different finishing and polishing (F/P) systems on surface roughness (SR) and microbial adhesion to bulk fill (BF) composites. Materials and Methods: An electronic search of 3 databases (the National Library of Medicine [MEDLINE/PubMed], Scopus, and ScienceDirect) was conducted. Only in vitro studies that evaluated SR and microbial adhesion to BF composites were included. The included studies were individually evaluated for the risk of bias following predetermined criteria. A meta-analysis of the reviewed studies was conducted to compare the SR values of both Filtek Bulk Fill and Tetric EvoCeram Bulk Fill with and without F/P using the Comprehensive Meta-Analysis software. Results: A total of 12 studies fulfilled the inclusion criteria. The meta-analysis showed no significant difference between Filtek Bulk Fill and Tetric EvoCeram Bulk Fill without F/P or after F/P using multi-step systems. Different F/P systems affected the SR values, on the other hand, did not affect microbial adhesion values. Conclusion: Both Filtek Bulk Fill and Tetric EvoCeram Bulk Fill had comparable roughness results. Multi-step systems may be preferable for F/P of BF composites.

Assessment of Microhardness of Conventional and Bulk-Fill Resin Composites Using Different Light-Curing Intensity

(1) Background: This study evaluates the effect of a conventional/low-voltage light-curing protocol (LV protocol) (10 s with 1340 mW/cm²) and high-voltage light-curing protocol (HV protocol) (3 s with 3440 mW/cm²) on the microhardness (MH) of dental resin-based composites (RBCs). Five resin composites were tested: conventional Evetric (EVT), Tetric Prime (TP), Tetric Evo Flow (TEF), bulk-fill Tetric Power Fill (PFL), and Tetric Power Flow (PFW). (2) Materials and Methods: Two tested composites (PFW and PFL) were designed for high-intensity light curing. The samples were made in the laboratory in specially designed cylindrical molds; diameter = 6 mm and height = 2 or 4 mm, depending on the type of composite. Initial MH was measured on the top and bottom surfaces of composite specimens 24 h after light curing using a digital microhardness tester (QNESS 60 M EVO, ATM Qness GmbH, Mammelzen, Germany). The correlation between the filler content (wt%, vol%) and the MH of the RBCs was tested. For the calculation of depth-dependent curing effectiveness, the bottom/top ratio for initial MH was used. (3) Conclusions: MH of RBCs is more dependent on material composition than on light-curing protocol. Filler wt% has a greater influence on MH values compared to filler vol%. The bottom/top ratio showed values over 80% for bulk composites, while for conventional sculptable composites, borderline or suboptimal values were measured for both curing protocols.

The Microhardness and Surface Roughness Assessment of Bulk-Fill Resin Composites Treated with and without the Application of an Oxygen-Inhibited Layer and a Polishing System: An In Vitro Study

The aim of this study was to assess the microhardness and surface roughness of bulk-fill resin composites treated with and without the application of an oxygen-inhibited layer (OIL) and a polishing system. This in vitro experimental study consisted of 72 resin composite blocks divided into three groups: Tetric N-Ceram Bulk Fill, Opus Bulk Fill APS, and Filtek Bulk Fill. Each resin composite group was further divided into two subgroups: with and without OIL control. Subsequently, surface roughness and microhardness were measured before and after polishing. A t-test was used to compare independent and related measures. For the intergroup comparison of variation before and after polishing, the Kruskal−Wallis test with Bonferroni post hoc was used considering a significance level of p < 0.05. When comparing surface roughness, significant differences were observed between Opus Bulk Fill resin composite with and without OIL control (p = 0.003) before polishing. The same occurred when comparing Tetric N-Ceram resin composite with and without OIL control (p = 0.039) after polishing. In addition, the surface roughness of Filtek Bulk Fill, Opus Bulk Fill, and Tetric N-Ceram Bulk Fill resin composites, with and without OIL control, decreased significantly after polishing (p < 0.001), while surface microhardness significantly increased (p < 0.05), with the exception of Opus Bulk Fill resin with OIL control (p = 0.413). In conclusion, OIL control and polishing significantly improved the surface roughness and surface microhardness of Filtek Bulk Fill and Tetric N-Ceram Bulk Fill resin composites. However, in the case of Opus Bulk Fill resin composite, only its surface roughness was significantly improved.