Study And Application Of Anatomical Healing Abutment For Mandibular First Molars

Objective: Scan,measure and analyze the neck morphology of mandibular first molar,obtain data,design and manufacture mandibular first molar implant supporting anatomical healing abutment,and evaluate the effect of mandibular first molar anatomical healing abutment on the morphological changes of gingival soft tissue after implant repair,as well as the gingival formation around the implant,food impaction and patient satisfaction,It provides a basis for clinical selection of healing abutment to obtain good aesthetics and function.Methods: 1.The buccal lingual diameter and mesial distal diameter of the tooth neck were obtained by scanning the isolated mandibular first natural molar with 3shape scanner,as well as the slope data of the four axial surfaces of the natural isolated tooth;After statistical analysis of the data,the anatomical healing abutment of mandibular first molar was designed and made by using the principle of computer-aided design /computer-aided manufacturing.2.From September 2020 to September 2021 in the dental implant center of Changsha stomatological hospital,26 patients with single mandibular first molar missing received implant restoration were randomly divided into control group(13 cases with14 implants)and experimental group(13 cases with 14 implants),including 12 males and 14 females.The experimental group received implant crown restoration after 4weeks of anatomical healing abutment,and the control group received implant crown restoration after 4 weeks of finished healing abutment.Before the second stage operation and 4 weeks after the formation of the healing abutment,the mandible was scanned by 3shape intraoral scanner,and the changes of soft tissue were analyzed quantitatively.The effect of the healing abutment on gingival formation,the incidence of food impaction after repair and the satisfaction of patients were compared.The data were statistically analyzed by SPSS 25.0 software.Results: 1.The mean values of buccal lingual diameter and mesial and distal median diameter of the natural isolated mandibular first molar CEJ 1mm downward were(7.87 ± 0.86mm),(8.54 ± 0.78mm),and the tooth neck slopes of each axial surface of the isolated mandibular first molar were 17.53 °,14.41 °,13.40 ° and 13.43 °respectively.Anatomical healing abutments with a height of 5mm were obtained by reducing a certain proportion according to the neck value of the natural mandibular first molar.2.After the second stage implantation operation,the increase of the proximal and middle gingival papilla to the crown in the experimental group was significantly higher than that in the control group,which was 0.45 ± 0.20 mm in the experimental group and 0.12 ± 0.50 mm in the control group,P = 0.026,(P < 0.05);The increase of distal gingival papilla to crown was different between the two groups,0.50 ± 0.36 mm in the experimental group and 0.25 ± 0.54 mm in the control group,P = 0.272,(P>0.05);The distal gingival papilla and buccal tongue formed to the crown from the apex of gingival margin in the two groups,and the amplitude of change was different,there was no significant difference,(P>0.05);The changes of buccal lingual direction of buccal and lingual soft tissue at 0,1 and 2mm of the root of 1 / 3 apex in the buccal and lingual gingival margin were different between the two groups,and there was no significant difference.Compared with the control group,the incidence of food impaction in the experimental group was no significant differenceat 4 weeks(T3)and12 weeks(T4)after mandibular first molar implant crown restoration,(P> 0.05).The satisfaction of the two groups was similar after the second stage of mandibular first molar implantation(T1)and 12 weeks(T3);Four weeks after crown restoration(T2),the satisfaction score of the experimental group was higher than that of the control group.Conclusion: A bionic anatomical anatomical healing abutment for mandibular first molars,which can be obtained quickly,has been successfully developed to help the rapid formation of gums after clinical application.The anatomic healing abutment of mandibular first molar with implant is better than the finished healing abutment in increasing the crown square of mesial gingival papilla.Compared with the soft tissue shaping of the finished healing abutment,the implant repair after the gingival shaping of the anatomical healing abutment can effectively improve the patient satisfaction.