statement of problem: the question about resistance of resin composites under rest in removable partial denture (rpd) is still unanswered. it is important to find the strongest material that withstands the applied stresses when used under rpd components. objectives: to evaluate and compare the fatigue behavior of amalgam and composite restorations used under the rest of the removable partial de...

background and aim: the present study aimed at determination of the fatigue resistance and failure mode of cusp-replacing onlays in endodontically treated premolars using indirect composite resin restorations. materials and method: in this experimental study, 84 human premolars were randomly divided into 7 groups of 12. these groups were prepared as follows: intact teeth used in group1 as contr...

OBJECTIVES To determine the influence of different etching times (5, 15 or 30 s) on the morphology and micro-tensile bond strength (muTBS) of primary dentin. METHODS For muTBS study, nine primary molars were randomly distributed in three experimental groups. Three Class I cavities per tooth were drilled and etched (37% orthophosphoric acid gel for 5, 15 or 30 s). Excite adhesive was applied a...

OBJECTIVE To assess the influence of ormocer, nanofilled, nanoceramic, and microhybrid composite restorative systems on the fracture resistance of maxillary premolars with Class II mesio-occlusodistal (MOD) cavities. METHOD AND MATERIALS Eighty-four sound maxillary human premolars were divided into six groups of 14 teeth each. Teeth in the first group were left intact and tested as unprepared...

The purpose of this study was to investigate the effect of modifying aluminum oxide slips with magnesium oxide (MgO) to create a jointing material for In-Ceram Alumina. Jointed In-Ceram Alumina bars with In-Ceram Alumina slips containing 0-1.0 mass% MgO were examined by a three-point bending test. Joint-free bars were also tested as controls. Fracture surfaces were evaluated by scanning electro...

The purpose of this study was to investigate the effect of rigidity of post core systems on stress distribution by the theoretical technique, finite element stress-analysis method. Three-dimensional finite element models simulating an endodontically treated maxillary central incisor restored with a zirconia ceramic crown were prepared and 1.5 mm ferrule height was provided. Each model contained...

AIMS The aim of this study was to test the influence of different curing protocols on dentin marginal adaptation and the hardness of two composites. METHODS AND MATERIALS Three light-curing-units (LCUs): Quartz-Tungsten-Halogen (QTH: 541 mW/cm2), Argon-Ion-Laser (AL: 277 mW/cm2), and Plasma-Arc-Curing (PAC: 1818 mW/cm2) and two composites FiltekZ250 (F) and Tetric Ceram HB (TC) were tested. S...

OBJECTIVE This study investigated the effect of different ferrule heights on endodontically treated premolars. MATERIAL AND METHODS Fifty sound mandibular first premolars were endodontically treated and then restored with 7-mm fiber post (FRC Postec Plus #1 Ivoclar-Vivadent) luted with self-polymerized resin cement (Multilink, Ivoclar Vivadent) while the coronal section was restored with hybr...

OBJECTIVES To evaluate the microtensile bond strength of total-etch or self-etch adhesives to caries-affected versus normal dentine, and to correlate these bond strengths with DIAGNOdent laser fluorescence and Knoop microhardness (KH) measurements of the substrates. METHODS Extracted carious human molars were ground to expose flat surfaces where the caries lesion was surrounded by normal dent...

AIM The aim of this study was to investigate the fracture resistance and failure mode of premolars restored with composite resin using various prefabricated posts. METHODS AND MATERIALS Sixty sound maxillary premolars were divided into four equal sized groups. All but the control group received endodontic treatment followed by placement of mesiodistocclusal (MOD) composite restorations (Tetri...