Fracture strength of teeth restored with ceramic inlays and overlays

Abstract

This study evaluated the fracture strength of teeth restored with bonded ceramic inlays and overlays compared to sound teeth. Thirty sound human maxillary premolars were assigned to 3 groups: 1-sound/unprepared (control); 2-inlays and 3-overlays. The inlay cavity design was Class II MOD preparation with an occlusal width of 1/2 of the intercuspal distance. The overlay cavity design was similar to that of the inlay group, except for buccal and palatal cusp coverage The inlay and overlay groups were restored with feldspathic porcelain bonded with adhesive cement. The specimens were subjected to a compressive load until fracture. Data were analyzed statistically by the Kruskal-Wallis test at 5% significance level. The fracture strength means (KN) were: Sound/unprepared group = 1.17, Inlay group= 1.17, and Overlay group = 1.14. There were no statistically significant differences (p>0.05) among the groups. For inlays and overlays, the predominant fracture mode involved fragments of one cusp (70% of simple fractures). The fracture strength of teeth restored with inlay and overlay ceramics with cusp coverage was similar to that of intact teeth.

Influence of surrounding wall thickness on the fatigue resistance of molars restored with ceramic inlay

“…3,4 However, a recurrent question regarding inlay restorations relates to cavity design, especially regarding the occlusal isthmus extension, and to when the cusps should be overlapped. 5,6,7,8,9 In the literature, recommendations can be found indicating that when the limits of the inlay cavity preparations are closer than 1.5 mm to the functional cusp, or when there is a less than 2 mm remaining thickness, an onlay preparation should be included, with a 2 mm axial reduction. 10 This principle of cavity preparation with cuspal coverage or overlap is based on metal cast restorations that do not adhere to dental substrates, and that are recommended to strengthen a weakened tooth declaration of interests: The authors certify that they have no commercial or associative interest that represents a conflict of interest in connection with the manuscript.…”

A Comparative Study To Evaluate The Fracture Resistance of Posterior Teeth Restored With Ceramic Inlay And Hybrid Composite Restoration – An In-Vitro Study.

“…reported that fracture strength of teeth restored with inlay and onlay ceramics are near to normal teeth. 48 Dejak et al . also reported that adhesively bonded composite resin and ceramic inlay reinforce the structure of the posterior teeth.…”

Critical Review and Evaluation of Composite/Ceramic Onlaysversus Crowns

“…2) There was no support found for the practice of replacing large amalgam and resin composite restoration with onlay or crowns to prevent potential tooth fractures. 3) Indirect anterior restorations with ceramometal crowns were more cost-effective than porcelain jacket crowns [50].…”