Examination on the effects of the cavity wall thickness and angle formation in the ceramic and composite inlays applied to the vital molar teeth on the stress distribution

Over the past few years, there has been a growing interest in restoringthe tissue loss occurring in the posterior teeth, due to the developments in theadhesive and restorative materials, with inlays.In this study, the effects of the cavity wall thickness and the angleformation in the ceramic and composite inlays applied to the vital mandibularfirst molars on the stress distribution were examined through the finite elementmethod.After the mandibular first molar and the surrounding tissues had beenmodelled, MOD cavities having three different cavity base widths and fourdifferent total occlusal convergence angles were formed. Models were restoredwith a ceramic and composite inlay having two different elasticity modules and aforce of 200N was used on a vertical axis provided that the contact points in 5mm diameter would stay within the limits of restoration. Equivalent stressfindings occurring in the dental structures were examined.When the analyses were studied, it was observed that the amount ofstress does not change as the wall thickness decreases in the molars restoredwith ceramic inlays while the amount of stress increases in the case of themolars restored with composite inlays. Furthermore, although the amount ofstress remains the same in the molar teeth restored with ceramic inlays as thetotal occlusal convergence angle increases, the amount of stress occurring wasobserved to increase as the total occlusal convergence angle increases in themolar teeth restored with composite inlays. In this study, it was concluded thatthe amount of stress transmitted to the remaining dental structures decreasesas the value of the elasticity module increases depending on the inlay materialused in the restoration of the vital molar teeth.