Comparison of fracture resistance of teeth restored with direct composite inlay, indirect composite inlay and indirect porcelain inlay restorations

COMPARISON OF FRACTURE RESISTANCE OF TEETH RESTORED WITHDIRECT COMPOSITE INLAY, INDIRECT COMPOSITE INLAY AND INDIRECTPORCELAIN INLAY RESTORATIONSDt. . Aylin Gençay LHANSUMMARYPatients demand of natural, healthy appearance the increase of awareness of the harmcaused by toxic and allergic materials, the increase of patients aesthetic expectations foranterior regions and also posterior regions made composite and porcelain inlays popular inmodern dentistry. The development of adesiv systems made the improvement of easy and fastapplication of inlay systems absolutely necessary.Together with the development of adesiv techniques and materials, composite andporcelain inlays caused restorative dentistry to gain new dimension. The adesiv materialsprotect the tooth structure and increase the resistance of the tooth during the performance oftheir functions by providing a good adhesion for both the tooth and the restoration. Besidesmany factors in the posterior region, the masticatory forces and fracture resistance of the toothplay a big role in the success of the restoration. The protection of the tooth by partialrestorations and the extension of the time to go over to a full restoration are approaches ofcontemporary prosthetics. By means of these approaches early tooth loss is prevented.This study is done in order to compare the differences, which may occur in the teethfracture resistance due to the application of direct composite inlay, indirect composite inlayand indirect porcelain inlay.This in-vitro study, 80 premolar teeth, extracted for periodontal and orthodonticreasons, without caries and restoration are used. Teeth are divided into four equal groups eachof them consists of 20. All of the teeth are fixed inside the self-curing acrylic blocks. The firstgroup is used as a control group. The standard class II inlay cavity is prepared on the otherthree groups. The second group is restored with direct composite inlay, the third group isrestored with indirect composite inlay, the fourth group is restored with indirect porcelaininlay.The fracture resistance of the teeth is measured with a Universal Test Instrumentavailable in the laboratory of Prosthodontic Department of Çukurova University.Data obtained from these measures are evaluated statistically by using ANOVA andPost-Hoc test. Approximate fracture resistance values were determined as follow; 655.3050N. for control group, 581.4100 N. For indirect composite inlay (Targis), 547.2250 N. forindirect porcelain inlay (IPS-Empress), 486.2950 N. for direct composite inlay.Among the groups, it was established that control group had the highest and the directcomposite inlay group had the lowest fracture resistance.Classification of the fracture resistance values, which was obtained after the statisticalanalyses, from the highest resistance to lower ones is as follow:Control > Indirect composite inlay (Targis) > Indirect porcelain inlay (IPS Empress) >Direct composite inlayKey words: Direct composite inlay, indirect composite inlay, indirect porcelain inlay,and Fracture resistance.