Does Er,Cr:YSGG reduce the microleakage of restorations when used for cavity preparation? A systematic review and meta-analysis

Influence of Different Enamel Pretreatment on Bond Strength of Fissure Sealant

Objective

The aim of this in vitro study was to evaluate the bond strength of a resin composite fissure sealant to enamel which was pre-treated with different laser pulse modes and additional acid etching.

Materials and Methods

Forty-two healthy molars and premolars were collected for this study and randomly divided into 6 groups (n=7). Group 1: Quantum Square Pulse (QSP); Group 2: Medium-Short Pulse (MSP) mode; Group 3: Super Short Pulse (SSP) mode; Group 4: QSP + acid etching; Group 5: MSP + acid etching; Group 6: SSP + acid etching. The occlusal surfaces of the teeth were pre-treated according to the defined group. Laser conditioning of the enamel was performed using an Er:YAG laser Fotona Light Walker AT-S (Fotona, Ljubljana, Slovenia) with a wavelength of 2940 nm + acid etching (EN etch Ivoclar Vivadent AG, Schaan, Liechtenstein). Occlusal surfaces were sealed with a resin-based composite fissure sealant (Helioseal F, Ivoclar Vivadent AG, Schaan, Liechtenstein). Micro-tensile bond strength (μTBS) test and stereomicroscope evaluations of the failure mode were performed. The μTBS was tested using the Games-Howell method. The failure mode between groups was tested using the chi-square test. The significance level for all tests was set at p <0.05.

Results

The highest bond strength was measured using laser etching in MSP mode combined with acid etching (36.09 MPa). This combination showed a significantly higher bond strength than the other combinations (SSP + ETCH, p<0.001; QSP + ETCH, p<0.001).

Conclusion

The SP laser followed by acid etching of enamel yielded the highest bond strength. Thus, the MSP with a 140 µs pulse mode might be the preferred choice as a pre-treatment procedure for fissure sealing.

Direct Composite Restorations on Permanent Teeth in the Anterior and Posterior Region - An Evidence-Based Clinical Practice Guideline - Part 2: Recommendations for Composite Processing

PURPOSE

Part 2 of this German S3 clinical practice guideline provides recommendations for the process of manufacturing composite restorations. It covers key aspects like caries removal, field isolation, matrix and adhesive techniques, as well as light curing and polishing. The outcomes of interest include survival rates and restoration quality.

MATERIALS AND METHODS

A systematic literature search was conducted by two methodologists using MEDLINE and the Cochrane Library via the OVID platform, including studies up to December 2021. Additionally, the reference lists of relevant manuscripts were manually reviewed. Six PICO questions were developed to guide the search. Consensus-based recommendations were for- mulated by a panel of dental professionals from 20 national societies and organizations based on the collected evidence and ex- pert opinion.

RESULTS

The guideline advocates for one-stage selective caries removal near the pulp and underscores the effectiveness of various isolation techniques, adhesive systems, and the crucial role of light polymerization. The use of anatomically pre- formed sectional matrices and phosphoric acid etching is recommended to enhance restoration quality. Additionally, polish- ing composite restorations is advised to improve surface finish.

CONCLUSION

This guideline provides comprehensive recommendations that inform clinicians on optimizing the composite restor- ation manufacturing processes. The adoption of these best practices can improve the quality and longevity of dental restorations.

Impact of acid and laser etching of enamel on microleakage in different adhesive systems

This study aimed to evaluate the microleakage of light-cured and self-cured adhesives on enamel surfaces selectively etched with Er, Cr: YSGG laser or 35% phosphoric acid. A total of 60 class V cavities were prepared 1 mm above the cemento-enamel junction (CEJ). The specimens were randomly divided into six groups. Group 1: Clearfil SE Bond with no conditioning, Group 2: Tokuyama Universal Bond with no conditioning, Group 3: Clearfil SE Bond conditioned with 35% phosphoric acid, Group 4: Tokuyama Universal Bond conditioned with 35% phosphoric acid, Group 5: Clearfil SE Bond conditioned with Er, Cr: YSGG laser and Group 6: Tokuyama Universal Bond conditioned with Er, Cr: YSGG laser. Microleakage was evaluated qualitatively (visually) and quantitatively (ImageJ). The data were analyzed using IBM SPSS V23 and submitted to Kruskal-Wallis and Wilcoxon tests. The significance level was set at p < 0.05. In all evaluation methods, the microleakage scores exhibit significant differences (p*<0.001). Group 1 and Group 3 exhibited similar and lower microleakage values than the Group 5. In the occlusal margin, the microleakage values were similar in Group 2, Group 4, and Group 6, whereas in the gingival margin Group 4 showed significantly lower leakage compared to Group 2. Regardless of the etching protocols and adhesive systems used, less microleakage was observed on the occlusal surface than on the gingival surface. Phosphoric acid etching provides better results than laser etching for enamel surface treatment on both occlusal and gingival surfaces.

Effects of different antibacterial disinfectants on microleakage of bulk-fill composite bonded to different tooth structures

Background

This in-vitro study aimed to investigate the effect of two different antibacterial disinfectants on the microleakage performance of newly developed bulk-fill composite, bonded to different tooth structures.

Methods

Class V cavities were prepared in 30 sound premolar teeth, with enamel occlusal margins (OM) and dentin cervical margins (CM). Two disinfectants, 2% chlorhexidine gluconate (CHX) and Listerine Miswak (ListM), were used. Teeth were divided into three groups (n = 10): G1, Control; G2, CHX; and G3, ListM. Disinfectants were applied to the cavity preparation walls after they were etched with 35% phosphoric acid. The Single Bond Universal adhesive system was then used, and teeth were restored with Filtek One Bulk Fill composite. Samples were examined, after thermocycling aging, by stereomicroscopy for the evaluation of marginal dye penetration.

Results

The highest mean microleakage score was reported in the CM of G1 (2.60 ± 1.174), which was significant compared with that of G2 only (p = 0.02). OM in G1 showed no microleakage, with no significant differences found among groups (χ² = 1.39, p = 0.50). No significant differences were reported between G2 and G3 (p = 0.45 OM; p = 0.17 CM).

Conclusions

Cavity pretreatment with CHX is not significantly different to pretreatment with CHX. In contrast, CHX improved the cervical marginal seal as compare to the control group (G1).