Microleakage in posterior teeth with different materials and different types of cavities

Fracture Resistance of Direct versus Indirect Restorations on Posterior Teeth: A Systematic Review and Meta-Analysis

The aim of this systematic review and meta-analysis was to compare static compression forces between direct composite resin restorations and indirect restorations for posterior teeth. All studies comparing mechanical properties of direct versus indirect restorations of posterior teeth were included from 2007 up to February 2024. A meta-analysis was conducted for static compression fracture resistance. Medline, Central, and Embase databases were screened. Twenty-four articles were included in the qualitative synthesis, and sixteen studies were finally included in the quantitative synthesis. There was no difference in terms of fracture resistance between direct and indirect restorations for posterior teeth (p = 0.16 for direct and indirect composite resin restorations and p = 0.87 for direct composite resin restorations and indirect ceramic restorations). Also, sub-group analysis with or without cusp coverage in each group revealed no discernable difference. Based on this study, it can be concluded that the choice between direct and indirect restoration approaches may not significantly impact fracture resistance outcomes. There was no statically significant difference between direct and indirect restorations for posterior teeth in all cases of restorations with or without cusp coverage and no matter the used materials. However, to better evaluate these materials, further studies are warranted.

Evaluation of the Sealing Ability of Direct versus Direct-Indirect Veneer Techniques: An In Vitro Study

BACKGROUNDS

Marginal discoloration, microleakage, wear, and marginal fractures are all prevalent problems with composite veneers, and this scenario leads the esthetic outcome to deteriorate with time, resulting in patient discontent. Aim of the Study. The study's goal was to determine the marginal sealing ability of composite laminate veneers when employing two types of veneer techniques: direct and direct-indirect veneers, as well as two types of composite resin: nanohybrid and microfilled composite resin restorations, using dye penetration method.

MATERIALS AND METHODS

In this study, forty extracted human teeth were utilized. Following a standardized veneer preparation on the labial surface of the teeth, they were separated into two groups of 20 teeth each, using the following composite application techniques: group A: direct veneers and group B: direct-indirect veneers. Following that, each major group was separated into two subgroups of ten teeth each, based on the type of composite employed: subgroup 1 used nanohybrid composite resin, while subgroup 2 used microfilled composite resin. All of the samples were kept in distilled water, thermocycled, and soaked in 2% basic fuchsine dye. These specimens were sectioned and examined under a stereomicroscope for dye penetration at the gingival margin. The data was analyzed using independent T-tests using SPSS 22.

RESULT

Using direct-indirect veneer technique with nanohybrid composite resin material resulted in the most negligible dye penetration at the gingival margin, while using direct veneer technique with microfilled composite resin material resulted in the maximum dye penetration. For both composite materials, gingival microleakage was lower when using the direct-indirect veneer technique than when using the direct technique, and the difference was statistically significant (P < 0.05). In both techniques, gingival microleakage was lower with nanohybrid composite than with microfilled composite, and the difference was statistically highly significant (P = 0.001).

CONCLUSION

The sealing ability of the gingival margin of tooth/composite interface is better when applying direct-indirect veneer technique with nanohybrid composite resin than that of direct veneer technique with microfilled composite resin material.

Comparison of microleakage between different restorative materials to restore marginal gap at crown margin

Background

An occurrence of secondary caries around the indirect restoration margin is reported to remain a leading cause of failures.

Objective

This study aimed to test the interfacial microleakage of conventional glass-ionomer (CGI), resin-modified glass ionomer (RMGI) and Nano-hybrid composite (CR) restorations at a full veneer margin crown.

Methods

Ninety human extracted molar teeth were divided into three groups (n = 30). Each group was subdivided into three subgroups (n = 10) according to the extent of the structural defects; The structural defect in G1 had a depth of 1.5 mm, width and length at 2 mm and 1 mm intrusion within the crown cervical margin. The corresponding structural defect dimension values for G2 were 2, 5, 4 and 2 mm with defects extending onto the root structure. Meanwhile, G3: structural deficiency of 2 mm depth, 3 mm width and 3 mm length and with 1.5 mm extension into the prepared teeth. These structural defects in each subgroup were restored with CGI, RMGI and CR. Artificial carious lesion formation was induced at the cervical finish line with a demineralizing solution. The artificial carious lesions were restored as per the group distribution. Subsequently, teeth samples were prepared and cemented with Nickel-chromium full coverage restorations utilizing glass-ionomer luting cement. Teeth samples were thermocycled, isolated with nail varnish, and immersed in 0.1% methylene blue for 24 h. The teeth samples were sectioned longitudinally, dye penetration was evaluated with a stereomicroscope. The data were analyzed with Kruskal–Wallis and Mann–Whitney U tests.

Results

CGI-G1 recorded the highest micro-leakage score at 1.450; while CR-G3 recorded the least score (0.350). At a cementum-restoration interface, CR-G1 (0.850) documented the lowest micro-leakage; RMGI-G3 had a greater value at 1.700.

Conclusions

The hybrid CR could be effectively used to restore the restoration of a marginal gap around crown margins.