Computer-aided design and computer-aided manufacturer indirect versus direct composite restorations: A randomized clinical trial.

OBJECTIVE: This study compared the clinical performance of large indirect restorations (IRs) versus direct restorations (DRs) in posterior teeth. METHODS: Thirty subjects received two class II restorations (n = 60), one fabricated from a precured composite block (Grandio Blocs, VOCO) for the indirect technique (IT) and the other with light-cured composite (GrandioSO, VOCO) for the direct technique (DT). For IT, the restoration was created using the computer-aided design and computer-aided manufacturer (CAD/CAM) system. For DT, the material was applied light-cured by using a layering technique. All restorations were evaluated by using the World Dental Federation criteria. RESULTS: Twenty-three subjects attended the 2-year recall, and 46 restorations were evaluated. No significant differences were detected between the techniques for most parameters analyzed (p > 0.05). For "color match" at 7 days and 6 months, better results were observed for the DT. In relation to the overall scores, all restorations were esthetically acceptable after 2 years, while 93.3% of DT and 90% of IT showed acceptable function. For biological scores, 96.67% of DRs and 100% of IRs was acceptable after 24 months. Considering all properties, the success rates were 93.3% for DRs and 90% for IRs. CONCLUSIONS: After 2 years, both restorations presented similar and good clinical behavior for all the properties analyzed. CLINICAL SIGNIFICANCE: Light-cured direct posterior composite restorations may perform similarly to indirect composite restorations made with precured CAD/CAM composite blocks up to 2 years.

Effect of Nd:YAG Laser with/without Graphite Coating on Bonding of Lithium Disilicate Glass-Ceramic to Human Dentin.

This study evaluated the effect of different surface treatments on the tensile bond strength between lithium disilicate glass-ceramics, resin cement, and dentin. Fifty truncated cone-shape glass-ceramics were divided into five groups (n = 10): G1, control: 10% hydrofluoric acid (HF); G2, Nd:YAG laser + silane; G3, Sil + Nd:YAG laser; G4, graphite + Nd:YAG laser + Sil; and G5, graphite + Sil + Nd:YAG laser. Fifty human third-molars were cut to cylindrical shape and polished to standardize the bonding surfaces. The glass-ceramic specimens were bonded to dentin with a dual-cured resin cement and stored in distilled water for 24 h at 37ºC. Tensile testing was performed on a universal testing machine (10 Kgf load cell at 1 mm/min) until failure. The bond strength values (mean ± SD) in MPa were G1 (9.4 ± 2.3), G2 (9.7 ± 2.0), G3 (6.7 ± 1.9), G4 (4.6 ± 1.1), and G5 (1.2 ± 0.3). Nd:YAG laser and HF improve the bond strength between lithium disilicate glass-ceramics, resin cement, and dentin. The application of a graphite layer prior to Nd:YAG laser irradiation negatively affects this bonding and presented inferior results.

Water-associated attributes in the contemporary dentin bonding milieu.

OBJECTIVES: The water-associated attributes of resin-dentin interfaces created by contemporary adhesives are important determinants of bond integrity and stability. In the present work, these attributes were estimated from the perspectives of causality, to examine the behavior of the first and most-recently launched versions of universal adhesives when applied in either the etch-and-rinse mode or the self-etch mode. METHODS: The immediate cause of interfacial permeability and the time-dependent cause of water sorption were investigated in conjunction with the intermediate effect of interface degradation and the more long-term effect of loss of mechanical strength, before and after thermomechanical cycling. The results were compared with control etch-and-rinse and self-etch adhesives. RESULTS: Although the introduction of this new class of universal adhesives has brought forth significant changes to the dental adhesion arena, including more application options, reduced bonding armamentarium and increased user friendliness, the water-associated attributes that are critical for making resin-dentin bonds more durable to environmental challenges and less susceptible to degradation have remained unchanged at large, when compared with benchmarks established by former classes of adhesives. CONCLUSION: It appears that the current trend of adhesive development has brought forth significant changes but lacks the vigor that demarcates progress and technological sublimity. CLINICAL SIGNIFICANCE: The advent of the user friendly universal adhesives has brought forth significant changes to the dental adhesion arena. However, the elements that are critical for making resin-dentin bonds more durable to environmental challenges and less susceptible to degradation have remained unchanged at large.