Clinical evaluation on aesthetic effect of custom pressable metal ceramic abutment for dental implant restoration in anterior zone / 华西口腔医学杂志

<p><b>UNLABELLED</b>OBJECTIVE To evaluate the aesthetic effect of restorations with custom pressable metal ceramic abutments for defective soft and hard tissue in the maxillary anterior zone.</p><p><b>METHODS</b>Fifty-two patients with missing anterior teeth in the maxillar were selected, who had problems such as exposure of abutment metal, excessively large angle deviation, excessively long ceramic crown and missing gingival papilla, affecting the aesthetic effect of implant denture. Custom pressable metal ceramic abutments were made on the conventional castable metal abutment surface and restored with all-ceramic crowns to overcome the blackness at the implant neck.</p><p><b>RESULTS</b>Clinical evaluation for aesthetic effects 3 and 6 months after the restorations were placed. In 63 restorations of 52 patients, the blackness at the implant neck were eliminated and the aesthetic effect were ideal. The gingival was in healthy condition, showing no further gingival retreat or inflammation around the implant denture.</p><p><b>CONCLUSION</b>Custom pressable metal ceramic abutments can effectively improve the aesthetic appearance of the implant denture in maxillary anterior zone.</p>

Effect of hot chemical etching on bond strength of zirconia to resin / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aims to evaluate the influence of hot chemical etching on short- and long-term shear bond strength (SBS) of zirconia to resin.</p><p><b>METHODS</b>Eighty zirconia ceramic slices were obtained and randomly divided into five groups based on the surface treatment to be applied--group A: H2SO4/(NH4)2SO4 hot solution etching + application of Clearfil; group B: HF/HNO3 hot solution etching + application of Clearfil; group C: H2SO4/HF/HNO3 hot solution etching + Clearfil; group D: alumina sandblasting + application of Clearfil; group E: tribochemical silica coating + application of silane coupling agent. Eighty composite cylinders were bonded to pretreated ceramic slices using a bis-GMA-based resin cement. Specimens in each group were divided into two fractions: the first half received 24 h water storage, and the second half received 40 d water storage. Then, SBS tests were conducted. Morphological analysis of sandblasted alumina and hot chemical-etched zirconia surfaces were performed by scanning electron microscopy(SEM).</p><p><b>RESULTS</b>Group E displayed the highest SBS before artificial aging, and no statistical difference was found among the other groups. After 40 d water storage, groups A, B, and E showed significantly higher SBS than groups C and D. SBS increased significantly after artificial aging in groups A and B. No significant variations were found before and after artificial aging in the other groups.</p><p><b>CONCLUSION</b>The experimental hot chemical etching solution provides enhanced bonding for zirconia than sandblasting, and the bond strengths remain stable after artificial aging.</p>