Dhillon Navneet, Kumar Manjit, D'Souza Dsj
Graded Specialist (Prosthodontics), MDC, BEG Kirkee (E), Pune.
Genesis Institute of Dental Sciences and Research, Moga Road, Ferozepur, Punjab.
Med J Armed Forces India. 2011 Jul;67(3):237-40. doi: 10.1016/S0377-1237(11)60049-X. Epub 2011 Aug 7.
Fabrication of fixed restorations is time consuming. It is vital that the prepared teeth be protected by means of an interim restoration till the time definitive prostheses can be delivered. Marginal adaptation is one of the most important requirements for an interim restoration.
This study was done to investigate the effect of water temperature and duration of immersion on the marginal accuracy of provisional restoration fabricated in autopolymerizing resin. The experimental model simulating a clinical situation was made. The test material was autopolymerizing methyl methacrylate. Specimens were subjected to different water temperatures for 5 and 10 minutes', duration for continuing the polymerization. Marginal accuracy was determined by a travelling microscope under 100 × magnification.
The measurements were tabulated and statistically analyzed using two way ANOVA technique. Results showed significant difference at all water temperatures. Marginal gaps were least when crowns were polymerized at 20°C for 5 minutes.
Study concluded that polymerizing the polymethyl methacrylate resin provisional crowns by direct technique in the water maintained at 20-30°C temperature for 10 minutes resulted in better marginal fit and this method can be utilized in clinical conditions for better results.
固定修复体的制作耗时较长。在最终修复体交付之前，通过临时修复体保护预备牙至关重要。边缘适合性是临时修复体最重要的要求之一。
本研究旨在调查水温及浸泡时间对自凝树脂制作的临时修复体边缘精度的影响。制作了模拟临床情况的实验模型。测试材料为自凝甲基丙烯酸甲酯。将试件置于不同水温下持续聚合5分钟和10分钟。通过100倍放大的移动显微镜确定边缘精度。
测量结果列表，并使用双向方差分析技术进行统计分析。结果显示在所有水温下均存在显著差异。当牙冠在20°C聚合5分钟时，边缘间隙最小。
研究得出结论，将聚甲基丙烯酸甲酯树脂临时牙冠通过直接技术在20 - 30°C水温下聚合10分钟可获得更好的边缘适合性，该方法可用于临床以取得更好的效果。
