ILAPEO College, Curitiba, Brazil.
Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA.
Clin Oral Implants Res. 2020 Mar;31(3):282-293. doi: 10.1111/clr.13569. Epub 2020 Jan 22.
This randomized clinical trial analyzed the long-term (5-year) crestal bone changes and soft tissue dimensions surrounding implants with an internal tapered connection placed in the anterior mandibular region at different depths (equi- and subcrestal).
Eleven edentulous patients were randomly divided in a split-mouth design: 28 equicrestal implants (G1) and 27 subcrestal (1-3 mm) implants (G2). Five implants were placed per patient. All implants were immediately loaded. Standardized intraoral radiographs were used to evaluate crestal bone (CB) changes. Patients were assessed immediately, 4, 8, and 60 months after implant placement. The correlation between vertical mucosal thickness (VMT) and soft tissue recession was analyzed. Sub-group analysis was also performed to evaluate the correlation between VMT and CB loss. Rank-based ANOVA was used for comparison between groups (α = .05).
Fifty-five implants (G1 = 28 and G2 = 27) were assessed. Implant and prosthetic survival rate were 100%. Subcrestal positioning resulted in less CB loss (-0.80 mm) when compared to equicrestal position (-0.99 mm), although the difference was not statistically significant (p > .05). Significant CB loss was found within the G1 and G2 groups at two different measurement times (T4 and T60) (p < .05). Implant placement depths and VMT had no effect on soft tissue recession (p > .05).
There was no statistically significant difference in CB changes between subcrestal and equicrestal implant positioning; however, subcrestal position resulted in higher bone levels. Neither mucosal recession nor vertical mucosa thickness was influenced by different implant placement depths.
本随机临床试验分析了在前下颌区域以不同深度（平齐和亚嵴下）植入具有内部锥形连接的种植体的长期（5 年）嵴顶骨变化和周围软组织尺寸。
11 名无牙患者随机分为分口设计：28 个平齐嵴种植体（G1）和 27 个亚嵴下（1-3mm）种植体（G2）。每位患者植入 5 个种植体。所有种植体均立即加载。使用标准的口腔内射线照相评估嵴顶骨（CB）变化。患者在植入后立即、4、8 和 60 个月进行评估。分析垂直黏膜厚度（VMT）与软组织退缩的相关性。还进行了亚组分析以评估 VMT 与 CB 丧失之间的相关性。基于等级的 ANOVA 用于组间比较（α=.05）。
评估了 55 个种植体（G1=28 个，G2=27 个）。种植体和修复体的存活率为 100%。与平齐嵴位置相比，亚嵴位置导致较少的 CB 丧失（-0.80mm），尽管差异无统计学意义（p>.05）。在 G1 和 G2 组的两个不同测量时间（T4 和 T60）均发现明显的 CB 丧失（p<.05）。种植体植入深度和 VMT 对软组织退缩没有影响（p>.05）。
在亚嵴和平齐嵴种植体定位之间，CB 变化没有统计学上的显著差异；然而，亚嵴位置导致更高的骨水平。黏膜退缩和垂直黏膜厚度均不受不同种植体植入深度的影响。
