A Case Report Of Gingival Wall Lift Combined With Onlay To Repair Subgingival Tooth Defect

Background: Subgingival tooth defect is prevalent in clinical practice.How to obtain a clear and accurate impression of the subgingival edge and improve the edge suitability of the prosthesis in the indirect restoration process are the difficulties in clinical operation.The traditional treatment methods are mainly crown lengthening and orthodontic traction,but large trauma,long cycle,and high cost limit its clinical application.With the development of oral bonding technology and the progress of material science,deep margin elevation(DME)is proposed as an alternative method.The resin is used to directly fill the subgingival edge to the supragingival,which makes the process of tooth preparation,impression preparation,moisture insulation,and bonding repair simple.Moreover,this technique has the advantages of small trauma,short clinical operation time,and the combination with adhesive onlay to repair posterior subgingival tooth defect is more in line with the current minimally invasive repair concept.Objective: In this study,we collected the cases of subgingival dental defects and performed DME technique combined with adhesive onlays to observe and evaluate the effect of clinical restoration,so as to provide a reference for the selection of clinical subgingival dental defects repairs scheme.Methods: Six patients were selected from September 2018 to February 2020 in the Department of Prosthodontics,Stomatological Hospital Affiliated to School of Stomatology,Dalian Medical University.Routine oral examination was performed before restoration,checking status of dental pulp,oral hygiene,occlusion and oral accessory function,assessing the risk of caries.The periapical film was taken to examine the periodontal disease of the tooth,and the depth of the subgingival tooth defect was preliminarily evaluated.The treatment plan was communicated.After the patient agreed,DME technology combined with onlay was used as the repair plan.Rubber barrier and matrix band were used to seal and form the gingival wall of the subgingival teeth.The subgingival edge was lifted to the supragingival by stratified filling with fluid resin and composite resin.Then,the onlay was prepared,colorimetric impression making,and the temporary resin was used for a temporary repair.One week later,the restoration was bonded.The gingival health status was evaluated before bonding.The immediate overall effect of the clinical repair was evaluated immediately after bonding by the shape and color matching of the prosthesis,edge suitability,and radiological examination.The patients were followed up for 12 months,and the tooth condition was evaluated by secondary caries,edge coloring,and tooth integrity.The periodontal conditions such as oral health,gingival inflammation,and alveolar bone resorption were evaluated by plaque index,gingival index,radiological examination,and mobility.The satisfaction of patients was evaluated through the aesthetic appearance of the prosthesis and the occlusal comfort of the prosthesis as well as the presence of food impaction and gingival bleeding,to evaluate the final repair effect comprehensively.Results: Evaluation of gingival health status before bonding: two patients were temporarily sealed with temporary resin after high-frequency electrosurgical excision of the free gingival,which delayed the healing of the gingival and caused gingival hyperemia,probing bleeding at the DME site.Immediate evaluation after bonding: The color transition between the restoration and natural teeth of one patient was not realistic at the edge line;Through radiological examination and clinical examination,the marginal fitness of six restorations was good.At the 12th-month follow-up,one patient had a moderate amount of plaque on the gingival margin of the repaired teeth and other teeth in the mouth,gingival edema,bleeding on probing,but no alveolar bone resorption.Six restorations did not appear secondary caries,and edge coloring;The residual tooth tissue around the restoration was intactc,no edge fracture;The six patients had no periodontal bone resorption or loosening of teeth compared with before the restoration.The aesthetic and functional recovery,periodontal condition,and comfort level of the prosthesis were evaluated satisfactorily.Conclusion: For the subgingival defect in the posterior region,DME technology combined with onlays can achieve a good restoration effect in moisture isolation and sealing,and does not invade the connective tissue under the junctional epithelium.The long-term effect needs to be observed.