Department of Prosthodontics, Faculty of Dentistry, Minia University, Minya, Egypt.
Department of Prosthodontics, Faculty of Dentistry, Sinai University, North Sinai Governorate, Egypt.
BMC Oral Health. 2024 Oct 4;24(1):1180. doi: 10.1186/s12903-024-04883-6.
To assess marginal bone loss and soft tissue health around two-implant mandibular overdenture retained with milled versus selective laser-melted cobalt chromium (Co-Cr) bars.
This research was set to be a parallel, triple-blinded, randomised controlled trial. Twenty completely edentulous patients received new conventional complete dentures according to conventional techniques. Two implants were placed at mandibular canine areas bilaterally, and patients were randomly allocated into two equal groups: the milled Co-Cr bar group and the selective laser melted (SLM) Co-Cr bar group. Marginal bone loss (MBL), modified plaque index (mPI), modified gingival index (mGI), and probing depth (PD) were evaluated at 0-month (baseline), 6-month, and 12-month follow-up visits. Repeated measures ANOVA test and Bonferroni's post-hoc test were used for parametric data as PD, while for non-parametric data as MBL, mGI, and mPI, Mann-Whitney U test and Friedman's test were used. A P-value ≤ 0.05 was set as the statistical level of significance. The study protocol was approved by the Faculty Research Ethics Committee at Minia University (636 4/10/2022). Registration for the clinical trial was made retrospectively on clinicaltrials.gov with ID NCT06401200 at 04/30/2024.
The follow-up period (one year) was completed without a dropout. Regarding MBL, no statistically significant difference was found between the two groups throughout the study. However, the milled group showed significantly increased MBL from 0- to 6-month follow up period. In both groups, mPI increased significantly from 0- to 6-months post-loading. On the other hand, no statistically significant difference between the two groups was found regarding mPI and mGI throughout the study follow-up periods. The PD was significantly lower in the milled compared to the SLM group at the 6- and 12-month follow up period.
Two-implant mandibular overdenture retained with milled or SLM Co-Cr bar can provide an acceptable treatment option for completely edentulous patients regarding marginal bone loss and soft tissue outcomes.
评估两种不同方式（铣削和选择性激光熔化钴铬（Co-Cr））制作的下颌种植覆盖义齿基台周围的边缘骨丢失和软组织健康状况。
本研究为平行、三盲、随机对照试验。20 名完全无牙的患者根据常规技术接受新的常规全口义齿。在双侧下颌犬齿区植入两颗种植体，患者被随机分为两组：铣削 Co-Cr 杆组和选择性激光熔化（SLM）Co-Cr 杆组。在 0 个月（基线）、6 个月和 12 个月随访时评估边缘骨丢失（MBL）、改良菌斑指数（mPI）、改良龈炎指数（mGI）和探诊深度（PD）。对于 PD 等参数数据，采用重复测量方差分析和 Bonferroni 事后检验；对于 MBL、mGI 和 mPI 等非参数数据，采用 Mann-Whitney U 检验和 Friedman 检验。P 值≤0.05 为统计学显著性水平。该研究方案获得了米尼亚大学（2022 年 6 月 3 日 6364/10/2022）的研究伦理委员会批准。临床研究于 2024 年 4 月 30 日在 clinicaltrials.gov 上进行了回顾性注册，注册号为 NCT06401200。
无患者脱落，随访期（一年）完成。在整个研究过程中，两组之间的 MBL 无统计学差异。然而，铣削组在 0-6 个月的随访期间显示出明显的 MBL 增加。在两组中，mPI 从加载后 0-6 个月均显著增加。然而，在整个研究随访期间，两组的 mPI 和 mGI 之间无统计学差异。在 6 个月和 12 个月的随访期间，铣削组的 PD 明显低于 SLM 组。
对于完全无牙患者，用铣削或选择性激光熔化钴铬制作的下颌种植覆盖义齿基台在边缘骨丢失和软组织方面提供了一种可接受的治疗选择。
