CLINICAL EVALUATION OF A NANO HYBRID COMPOSITE RESIN

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。在美国，80%的牙医使用后牙树脂复合材料。首次后路复合材料临床试验的结果发表于1971年。随后对相同修复体的召回显示，树脂复合修复体的耐磨性较差。早期的评论建议复合材料仅限于保守的双尖牙和第一磨牙修复，因为美学是关键。尽管树脂复合材料的改进，材料的限制存在，这限制了树脂复合材料的使用作为后路修复材料。在临床上，树脂修复是困难的，需要更多的放置时间比类似大小的汞合金修复。近端接触很难获得，因为复合材料是一种糊状材料，在聚合过程中会收缩；两项临床调查报告20%的后路复合修复体接触薄弱或有缺陷。复合树脂修复体的龋病复发是一个临床问题，主要是由于聚合收缩和修复体牙龈腔面边缘的开放。目前，诊断近端间复发性龋齿的最佳方法是咬牙x线片，x线片记录了脱矿（牙釉质和牙本质矿物质含量的损失）作为相应的放射密度下降。需要进一步开发具有更高耐磨性，降低聚合收缩和改进的粘合剂系统的复合树脂，使其与牙齿结构的结合更强。本研究将评估在1级和2级制剂中减少聚合收缩的复合材料的临床成功，以评估该复合材料是否将通过美国牙科协会建立的认证计划。具体目标：1；将复合树脂放置在I类和II类腔体准备中，根据具体标准（直接和间接）在基线、6个月、1年和18个月时评估树脂复合修复体。2. 评估树脂复合修复体18个月的染色、边缘完整性、对寒冷的反应、放置时间和近端接触。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Posterior resin composites are used by 80% of the dentists practicing in the United States. The results of the first clinical trial of posterior composites were published in 1971. Subsequent recalls of the same restorations revealed that the resin composite restorations had poor wear resistance. Early reviews recommended that composite be limited to conservative bicuspid and first molar restorations where esthetics was critical. In spite of improvements in resin composites, material limitations exist which restrict the use of resin composite as a posterior restorative material. Clinically, resin restorations are difficult and require more placement time tkhan a similar sized amalgam restoration. Interproximal contacts are difficult to obtain since composite is a paste material that shrinks during polymerization; two clinical investigations reported weak or defective contacts in 20% of the posterior composite restorations. The development of recurrent caries is a clinical problem with composite resin restorations primarily due to polymerization shrinkage and opening of the restoration gingival cavosurface margins. At present, the best means of diagnosing interproximal recurrent caries is with bitewing radiographs, which records demineralization (the loss of mineral content of the enamel and dentin) as a corresponding decrease in rediographic density. Further developments of composite resin with more wear resistance, reduced polymerization shrinkage and improved adhesive systems with stronger bonds to tooth structure are needed. This study will evaluate the clinical success of a composite with reduced polymerization shrinkage placed in class 1 and class 2 preparations to evaluate whether the composite will pass the certification program established by the American Dental Association. Specific Aims: 1. To place a composite resin in Class I and Class II cavity preparations, evaluate the resin composite restorations at baseline, 6 months, 1 year, and 18 months for specific criteria (direct and indirect). 2. To evaluate the resin composite restorations for staining, marginal integrity, response to cold, placement time, and proximal contact for 18 months.