放射治疗以及金属和陶瓷托槽粘结后牙釉质的物理和粘结性能

Physical and adhesive properties of dental enamel after radiotherapy and bonding of metal and ceramic brackets.

作者信息

Santin Gabriela Cristina, Palma-Dibb Regina Guenka, Romano Fábio Lourenço, de Oliveira Harley Francisco, Nelson Filho Paulo, de Queiroz Alexandra Mussolino

机构信息

Postgraduate student, Department of Pediatric Dentistry, School of Dentistry, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.

Professor, Department of Restorative Dentistry, School of Dentistry, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.

出版信息

Am J Orthod Dentofacial Orthop. 2015 Aug;148(2):283-92. doi: 10.1016/j.ajodo.2015.03.025.

DOI:10.1016/j.ajodo.2015.03.025

PMID:26232837

Abstract

INTRODUCTION

The increasing success rates for cancer patients treated with radiotherapy and the frequent occurrence of tooth loss during treatment have led to an increased demand for orthodontic treatment after radiotherapy. The aim of this study was to evaluate tooth enamel of irradiated teeth after the bonding and debonding of metal and ceramic brackets.

METHODS

Ten permanent molars were cut into enamel fragments measuring 1 mm(2) and divided into an irradiated group (total dose of 60 Gy) and a nonirradiated group. The fragments were subjected to microshear testing to evaluate whether radiotherapy altered the strength of the enamel. Furthermore, 90 prepared premolars were divided into 6 groups and subgroups (n = 15): group 1, nonirradiated and nonaged; group 2, nonirradiated and aged (thermal cycled); group 3, irradiated and aged; each group was divided into 2 subgroups: metallic and ceramic brackets. After thermal cycling and radiotherapy, the brackets were bonded onto the specimens with Transbond XT (3M Unitek, Monrovia, Calif). After 24 hours, the specimens were subjected to the shear tests. Images of the enamel surfaces were classified using the adhesive remnant index. The composite resin-enamel interface was also evaluated.

RESULTS

Enamel fragments subjected to radiation had lower strength than did the nonirradiated samples (P <0.05). The groups and subgroups submitted to radiation and bonded ceramic brackets had the lowest strength values. Groups 1 and 2 with metallic brackets had less adhesive on the surface, whereas groups 1 and 2 with ceramic brackets and group 3 with both metallic and ceramic brackets had more adhesive on the surfaces. On the images of the composite resin-enamel interface, resin tags were more extensive on irradiated tooth enamel.

CONCLUSIONS

Radiation decreased tooth enamel strength, and the specimens treated with radiotherapy had higher frequencies of adhesive failure between the bracket and the composite resin as well as more extensive tags.

摘要

引言

放射治疗癌症患者的成功率不断提高，且治疗期间牙齿脱落的情况频繁发生，这导致放疗后正畸治疗的需求增加。本研究的目的是评估金属和陶瓷托槽粘结和拆除后受照射牙齿的牙釉质情况。

方法

将十颗恒牙切成1平方毫米的牙釉质碎片，分为照射组（总剂量60Gy）和未照射组。对碎片进行微剪切测试，以评估放疗是否改变了牙釉质的强度。此外，将90颗预备前磨牙分为6组和亚组（每组n = 15）：第1组，未照射且未老化；第2组，未照射且老化（热循环）；第3组，照射且老化；每组再分为2个亚组：金属托槽和陶瓷托槽。经过热循环和放疗后，使用Transbond XT（3M Unitek，蒙罗维亚，加利福尼亚）将托槽粘结到标本上。24小时后，对标本进行剪切测试。使用粘结残留指数对牙釉质表面图像进行分类。还对复合树脂 - 牙釉质界面进行了评估。