片側遊離端無歯顎症におけるインプラント支持固定式部分床義歯患者の残存歯の状態に関する後方視的調査

Retrospective investigation of the remaining teeth status of patients with implant-supported fixed partial dentures in unilateral free-end edentulism.

抄録

目的:

本研究の目的は、片側遊離端無歯顎症のインプラント支持固定床義歯（IFD）、可撤性部分床義歯（RPD）、無修復（NR）患者における様々な合併症のない残存率と残存歯の生存率を比較することである。

PURPOSE: This study aimed to compare the various complication-free rates and survival rates of remaining teeth among implant-supported fixed dentures (IFDs), removable partial dentures (RPDs) and no-restoration (NR) patients with unilateral free-end edentulism.

材料と方法:

岡山大学歯学部附属病院にて片側性遊離端無歯顎症（2～3歯欠損）に対する補綴治療を受けた患者を対象とした。IFD群33名、RPD群41名、RPDを受けたが使用を拒否した10名をNR群とした。残存歯列は欠損部との関連で、欠損部の隣接歯（AD）、同顎の対側後方歯列（CS）および反対顎の対側後方歯列（CO）、同側の対側後方歯列（IO）、前方歯列（AN）の5つのサブカテゴリーに分類した。合併症は、抜歯、歯周病変、智歯周囲病変、補綴物の保持力喪失と定義し、病院カルテの記録に基づいて1人の検査者が評価した。

MATERIAL AND METHODS: The study subjects were selected among those who received prosthodontic treatment at Okayama University Dental Hospital for their unilateral free-end edentulism (2 or 3 missing teeth). Thirty-three patients were included in the IFD group, 41 matched patients in the RPD group, and 10 patients who received RPDs but refused their use were regarded as NR group. The remaining dentition was classified into five subcategories in relation to the missing portion: adjacent teeth to the missing portion (AD), contralateral posterior dentition in the same jaw (CS) and in the opposite jaw (CO), ipsilateral opposing posterior dentition (IO), and anterior dentition (AN). Complications were defined as tooth extraction, periodontal lesions, periapical lesions or loss of retention of the prosthesis and were assessed by one examiner based on the hospital chart records.

結果:

残存歯の累積無合併率は3群間で有意差があり(p<0.01)、IFD群で有意に低かった。残存歯の累積生存率については、IFD群とNR群にのみ有意差があり(p=0.01)、特にCO領域で有意差があった(p=0.04)。

RESULTS: The cumulative complication-free rates in the remaining teeth were significantly different among each of the three groups (p<0.01), with a significantly lower incidence rate in the IFD group. Regarding the cumulative survival rate of the remaining teeth, there was a significant difference only between IFD and NR group (p=0.01), especially in the CO region (p=0.04).

結論:

片側遊離端無歯顎症に対するIFD治療により得られた安定した後方咬合支持は、有害な機械的ストレスを減少させることにより、残存歯の合併症の発生率を減少させる可能性がある。

CONCLUSIONS: Stable posterior occlusal support obtained with IFD treatment for unilateral free-end edentulism may reduce the incidence of complications in the remaining teeth, by decreasing the adverse mechanical stress.