Alavi Ali Asghar, Behroozi Zeinab, Nik Eghbal Farid
Dept. Operative Dentistry and Biomaterials of Research Center, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
Dept. of Orthodontic, School of Dentistry, Yasuj University of Medical Sciences, Yasuj, Iran.
J Dent (Shiraz). 2017 Mar;18(1):50-55.
Porcelain laminate veneer is an esthetic restoration used as an alternative to full veneer crowns and requires minimal tooth preparation. In restoration with porcelain laminate veneers, both the longevity of the laminate and conservation of the sound tooth structure are imperative.
The present study aimed to investigate the shear bond strength of porcelain laminates to prepared- and unprepared- anterior teeth in order to compare their longevity and success rate.
Thirty extracted maxillary central incisors were randomly divided into 3 groups regarding their preparation methods. The preparation methods were full-preparation in group A, full-preparation and finishing with fine diamond bur in group B, and no-preparation, only grinding with diamond bur in group C. After conditioning the teeth, ceramic veneers (IP S e.max) were silanated and then cemented with DuoLink luting cement. The shear bond strength was measured for each group and failure mode was determined by stereomicroscopic examination.
Group C exhibited the highest shear bond strength. The shear bond strength was significantly different between groups C and B (< 0.05). However, the difference between group A and C was insignificant, as was the difference between group A and B (> 0.05). Adhesion failure mode was found to be more common than the cohesive mode.
Regarding the shear bond strength of unprepared anterior teeth to porcelain laminate veneers yielded by this study, no-preparation veneers might be used when the enamel is affected by wearing, trauma, or abrasion. It can also be used in patients who refuse the treatments which involve tooth reduction and preparation.
瓷贴面是一种美学修复体，可作为全冠修复的替代方案，且所需的牙齿预备量极少。在瓷贴面修复中，瓷贴面的使用寿命和保存完好的牙齿结构都至关重要。
本研究旨在调查瓷贴面与预备和未预备的前牙之间的剪切粘结强度，以比较它们的使用寿命和成功率。
30颗拔除的上颌中切牙根据预备方法随机分为3组。预备方法为：A组进行全预备；B组进行全预备并用细金刚砂车针进行修整；C组不进行预备，仅用金刚砂车针打磨。对牙齿进行处理后，对陶瓷贴面（IPS e.max）进行硅烷化处理，然后用DuoLink粘结剂粘结。测量每组的剪切粘结强度，并通过体视显微镜检查确定失败模式。
C组表现出最高的剪切粘结强度。C组和B组之间的剪切粘结强度有显著差异（<0.05）。然而，A组和C组之间的差异不显著，A组和B组之间的差异也不显著（>0.05）。发现粘结失败模式比内聚破坏模式更常见。
基于本研究得出的未预备前牙与瓷贴面之间的剪切粘结强度，当牙釉质受到磨损、外伤或磨耗影响时，可使用不预备的贴面。它也可用于拒绝涉及牙齿磨除和预备治疗的患者。
