使用紫外线和红外脉冲激光对牙本质中的蛋白质、水和矿物质进行选择性靶向：对与复合修复材料粘结强度的影响。

Selective targeting of protein, water, and mineral in dentin using UV and IR pulse lasers: the effect on the bond strength to composite restorative materials.

作者信息

Sheth Karishma K, Staninec Michal, Sarma Anupama V, Fried Daniel

机构信息

Department of Preventive and Restorative Dental Sciences, University of California-San Francisco, San Francisco, CA 94143-0758, USA.

出版信息

Lasers Surg Med. 2004;35(4):245-53. doi: 10.1002/lsm.20102.

DOI:10.1002/lsm.20102

PMID:15493023

Abstract

BACKGROUND AND OBJECTIVES

Previous studies have shown that during the laser irradiation of dentin and bone, thermal damage can be minimized by using a highly absorbed laser wavelength, laser pulses shorter than the thermal relaxation time of the deposited laser energy at that wavelength, and the addition of a layer of water to the tissue surface before ablation. The objective of this study was to investigate the influence of laser pulse duration and wavelength with and without the added water layer on the bond strength of composite to laser prepared dentin surfaces. The specific hypothesis that was tested was that thermal damage to the collagen matrix in dentin compromises the bond strength to composite restorative materials.

STUDY DESIGN/MATERIALS AND METHODS: Three laser systems were employed that were tuned to water, collagen, and mineral absorption with pulse durations less than the thermal relaxation time of the deposited energy. The surfaces of human dentin were irradiated by laser irradiation from free-running and Q-switched Er:YSGG lasers, pulsed CO(2) lasers operating at 9.6-microm, and a Q-switched Nd:YAG laser operating at 355-nm. A motion control system and a pressurized spray system incorporating a microprocessor controlled pulsed nozzle for water delivery, were used to ensure uniform treatment of the entire surface. Shear bond testing was used to evaluate the adhesive strength in order to access the suitability of laser treated surfaces for bonding. Bonded interfaces were examined by SEM.

RESULTS

All the laser groups had significantly lower bond strengths than the positive acid etch control group. The highest bond strengths were for the short pulse (< 5-microsecond) Er:YSGG and CO(2) laser groups with water. Laser groups without water had significantly reduced bond strengths and thicker layers of thermally damaged dentin.

CONCLUSIONS

Thermal damage to the collagen matrix profoundly influences the bond strength to composite restorations.

摘要

背景与目的

先前的研究表明，在牙本质和骨的激光照射过程中，通过使用高吸收性激光波长、短于该波长下沉积激光能量热弛豫时间的激光脉冲以及在消融前在组织表面添加一层水，可以将热损伤降至最低。本研究的目的是调查有无添加水层时激光脉冲持续时间和波长对复合材料与激光制备的牙本质表面粘结强度的影响。所检验的具体假设是，牙本质中胶原基质的热损伤会损害与复合修复材料的粘结强度。

研究设计/材料与方法：使用了三种激光系统，其被调谐至水、胶原和矿物质吸收峰，脉冲持续时间短于沉积能量的热弛豫时间。用自由运转和调Q的Er:YSGG激光、波长为9.6微米的脉冲CO₂激光以及波长为355纳米的调Q Nd:YAG激光对人牙本质表面进行激光照射。使用运动控制系统和一个带有微处理器控制脉冲喷嘴用于输水的加压喷雾系统，以确保对整个表面进行均匀处理。采用剪切粘结试验来评估粘结强度，以确定激光处理表面用于粘结的适用性。通过扫描电子显微镜检查粘结界面。