Abstract:

Objective: To evaluate whether the incidence of peri-implantitis was associated with adjacent implants inserted at different inter-implant distances. Methods: The bilateral mandibular teeth from second premolar to first molar of 6 beagle dogs were extracted. After tooth extraction for 8 weeks, the implants were placed with the help of a digital surgical guide. Each dog received 4 implants in the hemimandible. Implants were placed so that 3 inter-implant distances were created at 1, 2, 3 mm group. The peri-implant clinical periodontal indexes were recorded at the time of 2 weeks and 3 months after implant placement. Samples from peri-implant soft tissue were collected and analyzed by sequencing the bacterial 16S rRNA gene. X-ray parallel projection radiographs were taken for imaging measurement at the time of 1, 2, 3 months after implant placement. After 3 months of dental implantation, the mandibular bones were retrieved. The sections were stained with Van Gieson（VG） dye solution. Statistical analysis was performed with SPSS 25.0 software. Results: The indexes of probing depth（PD）, bleeding on probing(BOP) and plaque index(PI) of 1 mm group were significantly higher than 2 mm and 3 mm groups. The frequencies of the sites about PI≥2 were significantly the highest in 1 mm group, and so were the sites about PD≥5 mm or BOP(+) meeting the criteria of peri-implantitis. The analysis of the microbial community structure showed that the relative abundance of Treponema, Tannerella and Prevotella in 1 mm group was higher than that in 3 mm group. Statistically significant differences were found in regard to marginal bone resorption(MBR) and crestal bone resorption（CBR） in comparing 1 mm group with the other two groups by X-ray examination. Histological observation revealed that 1 mm group showed lower crest bone position than the other two groups. There were no significant differences between 2 mm and 3 mm groups in the above results. Conclusion: This study demonstrates that peri-implantitis is more likely to happen in 1 mm inter-implant distance than that in 2 mm and 3 mm distances. 1 mm distance group showed the highest PI and significant bone resorption and soft tissue inflammation， while no significant bone resorption happened in 2 mm and 3 mm distance group.

Key words: inter-implant distance, peri-implantitis, animal model, digital surgical guide, bone resorption

摘要：

目的：探究不同种植体间距与种植体周炎发生的关系。方法：拔除6只比格犬的双侧下颌第二前磨牙至第一磨牙，拔牙后8周在数字化外科导板辅助下行种植术。每侧植入连续的4枚种植体，种植体间距分别设置为1、2、3 mm，共3个组别。术后2周和3个月时记录种植体周临床牙周指数，术后3个月时采集种植体龈周菌斑行16S rRNA基因测序，分别于术后1、2、3个月时拍摄X线平行投照根尖片进行影像学测量；术后3个月时进行取材，制作硬组织切片并行Van Gieson（VG）染色，用SPSS 25.0软件作统计学分析。结果：1 mm组的种植体周探诊深度（probing depth, PD）、探诊出血（bleeding on probing, BOP）阳性率、菌斑指数（plaque index, PI）均明显高于2 mm组和3 mm组；1 mm组中，满足PI≥2的检测位点数最多，且符合种植体周炎诊断标准的PD≥5 mm或BOP阳性检测位点数明显高于其他2组。菌斑群落结构分析显示，1 mm组密螺旋体属（Treponema）、坦纳菌属（Tannerella）和普氏菌属（Prevotella）的相对丰度较3 mm组更高。X线片结果显示，1 mm组边缘骨吸收（marginal bone resorption，MBR）与嵴顶骨吸收（crestal bone resorption，CBR）明显大于其他2组。组织学观察结果显示，3组中，1 mm组骨嵴顶高度较其他2组明显降低。2 mm组与3 mm组比较，以上指标的差异均无统计学意义。结论：相对于2 mm组和3 mm组，1 mm组PI最高，且发生了明显的骨吸收和软组织炎症，而2 mm组和3 mm组没有发生明显的骨吸收。因此，1 mm的种植体间距更容易发生种植体周炎。

关键词: 种植体间距, 种植体周炎, 动物模型, 数字化外科导板, 骨吸收

CLC Number: 

• R782.4