Abstract：
It is urgently necessary to clarify the effect of extraction of impacted mandibular third molar (IMTM) on the periodontal tissue of adjacent second molars (ASMs). In this study, the ASM periodontal condition and pathogenic microbes were assessed before IMTM extraction and at 1, 4, 8 and 12 weeks postoperatively. Based on the inclusion and exclusion criteria, our study revealed that IMTM extractions adversely affected distal － periodontal probing depth (dPPD), attachment loss (dAL), plaque index (dPLI) and bleeding on probing (dBOP) within 8 weeks, but these indices gradually normalize after 12 weeks. The subgingival pathogens near the ASMs distal surface, Porphyromonas and Pseudomonas, were significantly increased postoperatively. Moreover, relevance of ASMs clinical indices and subgingival microbes after IMTM extractions was found. In contrast to the situation in chronic periodontitis, the effects of IMTM extraction on dPPD, dAL, dPLI and dBOP of ASMs were mainly correlated with Pseudomonas. Additionally, while the IMTM extractions have adverse distal periodontal indices of ASMs within 8 weeks and increase subgingival pathogens, the modified triangular flap (MTF) had fewer distal periodontal indices and less Pseudomonas. Compared to the traditional envelope flap and triangular flap, the MTF benefits the periodontal health, which could be considered as the priority option for IMTM extractions.
摘要：
迫切需要阐明下颌阻生第三磨牙（IMTM）拔除对邻近第二磨牙（ASM）牙周组织的影响。在这项研究中,在IMTM拔除前和术后1、4、8和12周评估ASM牙周状况和病原微生物。根据纳入和排除标准，我们的研究表明，IMTM提取对远端牙周探诊深度(dPPD)产生不利影响，附着损失(dAL)，8周内菌斑指数（dPLI）和探查出血（dBOP），但是这些指数在12周后逐渐恢复正常。ASM远端表面附近的龈下病原体，卟啉单胞菌和假单胞菌,术后显著增加。此外，发现IMTM提取后ASMs临床指标与龈下微生物的相关性。与慢性牙周炎的情况相反，IMTM提取对dPPD的影响，dAL,ASM的dPLI和dBOP主要与假单胞菌有关。此外,而IMTM摘除术在8周内对ASM的远端牙周指数不利，并增加龈下病原体，改良三角瓣（MTF）的远端牙周指数较少，假单胞菌较少。与传统的包络皮瓣和三角皮瓣相比，MTF有益于牙周健康，这可以被认为是IMTM提取的优先选项。
