Mitra Aditya, Sharma Snigdha, Bhattacharyya Anirban, Maity Asim Bikash, Majumder Gayatri, Datta Soham
Department of Conservative Dentistry and Endodontics, Haldia Institute of Dental Sciences and Research, Haldia, West Bengal, India.
J Conserv Dent Endod. 2024 Dec;27(12):1285-1288. doi: 10.4103/JCDE.JCDE_699_24. Epub 2024 Dec 10.
The stress distribution of a restored tooth is different from that of an intact sound tooth. The fracture resistance of a restored tooth depends on cavity design, remaining tooth structure, and material used.
This study evaluated and compared the fracture resistance of mandibular molars restored using composite resin.
Forty freshly extracted, intact mandibular molars were used, with their roots embedded in acrylic resin for stability. Cavities were prepared using a No. 2 round bur and straight fissure diamond, then divided into four groups with specific variations in cavity dimensions. Samples were tested using a universal testing machine, applying vertical load along the long axis at the central fossa to record fracture load.
One-way analysis of variance and Tukey's analysis were used for statistical analysis.
Fracture resistance of the groups, listed in descending order, was: Lingual wall 1.5 mm (2417 ± 160 N) > Buccal wall 1.5 mm (2122 ± 75.9 N) > Lingual wall 1 mm (1966 ± 75.7 N) > Buccal wall 1 mm (1335 ± 216 N).
The lingual wall 1.5 mm exhibited the highest fracture resistance, while the buccal wall with 1 mm thickness showed the least resistance.
修复后牙齿的应力分布与完整健康牙齿不同。修复后牙齿的抗折性取决于窝洞设计、剩余牙体结构和所用材料。
本研究评估并比较使用复合树脂修复的下颌磨牙的抗折性。
使用40颗新鲜拔除的完整下颌磨牙，将其牙根嵌入丙烯酸树脂以保持稳定。用2号圆钻和直裂金刚石制备窝洞，然后根据窝洞尺寸的特定变化分为四组。使用万能试验机对样本进行测试，沿中央窝的长轴施加垂直载荷以记录折断载荷。
采用单因素方差分析和Tukey分析进行统计分析。
各组抗折性从高到低依次为：舌侧壁1.5毫米（2417±160牛）＞颊侧壁1.5毫米（2122±75.9牛）＞舌侧壁1毫米（1966±75.7牛）＞颊侧壁1毫米（1335±216牛）。
舌侧壁1.5毫米的抗折性最高，而厚度为1毫米的颊侧壁抗折性最低。
