Kantovitz K R, Cabral L L, Carlos N R, de Freitas A Z, Peruzzo D C, Franca Fmg, do Amaral Flb, Basting R T, Puppin-Rontani R M
*Kamila Rosamilia Kantovitz, DDS, MS, PhD, Faculdade São Leopoldo Mandic, Dental Material Area Campinas, SP, Brazil. State University of Campinas (UNICAMP), Piracicaba Dental School, Department of Pediatric Dentistry, Piracicaba, SP, Brazil.
Lais Lemos Cabral, DDS, MS, Faculdade São Leopoldo Mandic, Dental Material Area Campinas, SP, Brazil. University Center Tiradentes (UNIT), Restorative Dentistry Area, Maceió, AL, Brazil.
Oper Dent. 2021 Sep 1;46(5):537-546. doi: 10.2341/20-144B-L.
The aim of this in vitro study was to quantitatively evaluate the internal gap of resin composites of high-and low-viscosity used in single- and incremental-fill techniques in Class I cavities exposed to thermal cycling (TC) using optical coherence tomography (OCT). Cavities of 4-mm depth and 3-mm diameter were prepared in 36 third molars randomly distributed into four groups, according to viscosity of restorative resin-based composite (high or low viscosity, all from 3M Oral Care) and technique application (bulk or incremental fill) used (n=9): RC, high-viscosity, incremental-fill, resin-based composite (Filtek Z350 XT Universal Restorative); BF, high-viscosity, bulk-fill, resin-based composite (Filtek One Bulk Fill); LRC, lowviscosity, incremental-fill, resin-based composite (Filtek Z350 XT Flowable Universal Restorative); and LBF, low-viscosity, bulk-fill, resin-based composite (Filtek Flowable Restorative). Single Bond Universal Adhesive system (3M Oral Care) was used in all the experimental groups. The incremental-fill technique was used for RC and LRC groups (2-mm increments), and a single-layer technique was used for BF and LBF groups, as recommended by the manufacturer. The internal adaptation of the resin at all dentin walls was evaluated before and after TC (5000 cycles between 5°C and 55°C) using OCT images. Five images of each restored tooth were obtained. Images were analyzed using ImageJ software that measured the entire length of the gaps at the dentin-restoration interface. The length of gaps (μm) was analyzed using two-way repeated measures ANOVA and the Tukey tests (α=0.05). There was a significant interaction between material types and TC (p=0.006), and a significant difference among all material types (p<0.0001), before and after TC (p<0.0001). Increased internal gaps at the dentin-restoration interface were noticed after TC for all groups. RC presented the lowest value of internal gap before and after TC, while LBF showed the highest values of internal gap after TC. In conclusion, TC negatively affected the integrity of internal gap, whereas high-viscosity, incremental-fill, resin-based composite presented better performance in terms of internal adaptation than low-viscosity, bulk-fill materials in Class I cavities.
本体外研究的目的是使用光学相干断层扫描（OCT）定量评估在经受热循环（TC）的I类窝洞中采用单层充填和分层充填技术时，高粘度和低粘度树脂复合材料的内部间隙。在36颗第三磨牙上制备深度为4毫米、直径为3毫米的窝洞，根据修复性树脂基复合材料的粘度（高粘度或低粘度，均来自3M口腔护理产品）和应用技术（整体充填或分层充填）随机分为四组（n = 9）：RC组，高粘度、分层充填、树脂基复合材料（Filtek Z350 XT通用修复材料）；BF组，高粘度、整体充填、树脂基复合材料（Filtek One整体充填材料）；LRC组，低粘度、分层充填、树脂基复合材料（Filtek Z350 XT可流动通用修复材料）；LBF组，低粘度、整体充填、树脂基复合材料（Filtek可流动修复材料）。所有实验组均使用单键通用粘结系统（3M口腔护理产品）。RC组和LRC组采用分层充填技术（每次增量2毫米），BF组和LBF组按照制造商的建议采用单层技术。使用OCT图像在热循环（5℃至55℃之间5000次循环）前后评估所有牙本质壁处树脂的内部适应性。每颗修复牙获取五张图像。使用ImageJ软件分析图像，该软件测量牙本质-修复体界面处间隙的全长。使用双向重复测量方差分析和Tukey检验（α = 0.05）分析间隙长度（μm）。材料类型和热循环之间存在显著交互作用（p = 0.006），所有材料类型之间存在显著差异（p < 0.0001），热循环前后也存在显著差异（p < 0.0001）。所有组在热循环后牙本质-修复体界面处的内部间隙均增加。RC组在热循环前后的内部间隙值最低，而LBF组在热循环后的内部间隙值最高。总之，热循环对内部间隙的完整性有负面影响，而在I类窝洞中，高粘度、分层充填的树脂基复合材料在内部适应性方面比低粘度、整体充填材料表现更好。
