Zhang Z, Meng H X, Han J, Zhang L, Shi D
Department of Periodontology, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2020 Apr 18;52(2):332-338. doi: 10.19723/j.issn.1671-167X.2020.02.022.
To observe and investigate the effect of vertical soft tissue thickness on the peri-implant tissue condition and the prevalence of peri-implant disease in patients with history of periodontitis.
Among 210 patients who showed initial interest of implant therapy, 92 patients were included in this study and received implant surgery during 2010 and 2015. Sixty-six patients with 66 implants finally came back for T2 evaluation. Prior to the implant therapy, all the patients had received periodontal treatment. During the implant placement surgery, the distance from palatal soft tissue edge to the alveolar crest, which was defined as vertical soft tissue thickness (VT), was measured after the buccal full thickness flap was elevated. According to the cut off point which was adopted from the operating characteristic curve, 66 implants within 66 patients were divided into two groups, which were called normal group (VT≤4.5 mm) and thick group (VT>4.5 mm), respectively. Information of the patient's general status, periodontal situation and implant information were recorded. After a follow-up period of 42.9 months, the parameters of peri-implant tissue and condition of peri-implant disease were recorded. Mann-Whitney U test as well as Chi-square test were used to compare the parameters between two groups. Moreover, Kaplan-Meier method was chosen to draw the event(peri-implantitis)-free survival curve.
The survival rate of the implants was 100%. At the end of the follow-up examination(T2), the parameters including max PDi, mean PDi, max BIi, mean BIi, mean MBL, MBL at distal side, MBL at mesial side, mean PLIi presented significantly higher values in thick group than in normal group (P < 0.05). Moreover, the prevalence of peri-implantitis and peri-implant disease (peri-implant mucositis & peri-implantitis) in thick group was respectively 34.8% and 73.9%, which was significantly higher than 2.3% and 48.8% respectively in normal group (P<0.05). The prevalence of peri-implant mucositis did not show significant difference in the two groups. In addition, Kaplan-Meier analysis showed that there was significant difference between the event-free survivals of the two groups.
The vertical soft tissue thickness around implants in patients with periodontitis has a significant effect on the health of the peri-implant tissue. Excessive vertical soft tissue thickness may result in deeper peri-implant probing depth as well as more peri-implant marginal bone loss, and eventually increase the risk of peri-implant disease. The vertical remodeling of soft tissue may be a new direction to indicate the role of periodontitis in peri-implant tissue condition. Moreover, the biological mechanism of the association between soft tissue thickness and peri-implantitis risk as well as effective approaches to prevent the adverse effect of excessive soft tissue thickness on peri-implant tissue is necessary to be investigated.
观察和研究垂直软组织厚度对有牙周炎病史患者种植体周围组织状况及种植体周围疾病患病率的影响。
在210例对种植治疗有初步兴趣的患者中，92例患者被纳入本研究，并于2010年至2015年期间接受了种植手术。最终66例患者的66枚种植体返回进行T2评估。在种植治疗前，所有患者均接受了牙周治疗。在种植体植入手术过程中，在翻起颊侧全厚瓣后，测量腭侧软组织边缘至牙槽嵴的距离，将其定义为垂直软组织厚度（VT）。根据从操作特征曲线采用的截断点，将66例患者的66枚种植体分为两组，分别称为正常组（VT≤4.5mm）和厚组（VT>4.5mm）。记录患者的一般状况、牙周情况和种植体信息。经过42.9个月的随访期后，记录种植体周围组织参数和种植体周围疾病状况。采用Mann-Whitney U检验以及卡方检验比较两组之间的参数。此外，选择Kaplan-Meier方法绘制无事件（种植体周炎）生存曲线。
种植体的生存率为100%。在随访检查结束时（T2），厚组的最大探诊深度（PDi）、平均探诊深度、最大出血指数（BIi）、平均出血指数、平均边缘骨丢失（MBL）、远中侧MBL、近中侧MBL、平均菌斑指数（PLIi）等参数显著高于正常组（P<0.05）。此外，厚组种植体周炎和种植体周围疾病（种植体周围黏膜炎和种植体周炎）的患病率分别为34.8%和73.9%，显著高于正常组的2.3%和48.8%（P<0.05）。两组种植体周围黏膜炎的患病率没有显著差异。此外，Kaplan-Meier分析表明两组的无事件生存率之间存在显著差异。
牙周炎患者种植体周围的垂直软组织厚度对种植体周围组织健康有显著影响。垂直软组织厚度过大可能导致种植体周围探诊深度更深以及种植体周围边缘骨丢失更多，并最终增加种植体周围疾病的风险。软组织的垂直重塑可能是一个新的方向，以表明牙周炎在种植体周围组织状况中的作用。此外，软组织厚度与种植体周炎风险之间关联的生物学机制以及预防软组织厚度过大对种植体周围组织产生不良影响的有效方法有待研究。
