Macedo Vanessa Cruz, Pereira Priscilla Cristoforides, Queiroz José Renato Cavalvanti de, Dal Piva Amanda Maria de Oliveira, Moura Dayanne Monielle Duarte, Tango Rubens Nisie, Bottino Marco Antonio, Souza Rodrigo Othávio de Assunção E
Oral Health Prev Dent. 2020 Apr 3;18(2):153-159. doi: 10.3290/j.ohpd.a44321.
The air-particle-abrasion on zirconia in the gingival area of connectors and pontics in fixed partial dentures appears to increase fracture resistance. This study evaluated 'in situ' biofilm formation on the zirconia surface after different air-particle-abrasion protocols.
Ninety sintered blocks (5 × 5 × 2 mm) of yttrium partially stabilised zirconia (Y-TZP) were obtained and randomised among nine groups according to the factors 'type of particle' (Alumina 50 and 110 µm; Cojet and Rocatec) and 'pressure' (2.5 and 3.5 bar) used for sandblasting for 10 s. The surface roughness (Ra/Rz) was measured before and after sandblasting. For the in-situ analyses, custom-made removable intraoral devices n = 10 with one sample of each group attached to the buccal area were used by volunteers for 8 h at night. The specimens were analysed under confocal microscopy to quantify both biovolume and thickness of the initial biofilm formed. One-way analysis of variance (ANOVA) and Dunnett's tests were performed (5%).
The roughness values ranged from 0.05 to 0.39 µm for Ra and from 0.35 to 2.11 µm for Rz, p = 0.00. Mean biofilm thickness ranged from 0.06 and 0.54 µm (p = 0.005), while the biovolume values were between 0.02 and 0.61 µm3/µm2 (p = 0.002). Values statistically significant for biofilm thickness and biovolume were found in groups sandblasted with Rocatec using 3.5 bar.
In order to increase the fracture resistance of zirconia fixed partial dentures (FPDs), the air particle abrasion of zirconia with SiO2 (110 μm/3.5 bar), in the gingival area of connectors and pontics, should be avoided.
在固定局部义齿的连接体和桥体牙龈区域对氧化锆进行空气颗粒研磨似乎可提高抗折性。本研究评估了不同空气颗粒研磨方案后氧化锆表面的“原位”生物膜形成情况。
获取90个钇部分稳定氧化锆（Y-TZP）烧结块（5×5×2 mm），并根据用于喷砂10秒的“颗粒类型”（50和110 µm氧化铝；Cojet和Rocatec）和“压力”（2.5和3.5 bar）这两个因素随机分为9组。在喷砂前后测量表面粗糙度（Ra/Rz）。对于原位分析，志愿者使用定制的可摘口腔内装置（n = 10），每组的一个样本附着在颊侧区域，夜间佩戴8小时。在共聚焦显微镜下对标本进行分析，以量化形成的初始生物膜的生物体积和厚度。进行单因素方差分析（ANOVA）和Dunnett检验（5%）。
Ra的粗糙度值范围为0.05至0.39 µm，Rz为0.35至2.11 µm，p = 0.00。平均生物膜厚度范围为0.06至0.54 µm（p = 0.005），而生物体积值在0.02至0.61 µm3/µm2之间（p = 0.002）。在用3.5 bar的Rocatec喷砂的组中发现生物膜厚度和生物体积具有统计学意义的值。
为了提高氧化锆固定局部义齿（FPD）的抗折性，应避免在连接体和桥体的牙龈区域用SiO2（110μm/3.5 bar）对氧化锆进行空气颗粒研磨。
