Correlation Between Different Jumping Gap And Soft Tissue Changes Around Immediately Placed And Restored Implants In The Maxillary Anterior Region

Objective: The purpose of this study was to evaluate the correlation between changes in periimplant soft tissue in aesthetic area of maxillary anterior teeth and changes in intraoperative jumping gaps,and to observe the effect of different jumping gap on the volume of labial gingival contour after immediate implant placement and restoration of anterior teeth.A new measurement method was proposed to provide a basis for clinical evaluation of the variation trend and long-term stability of labial gingival.Methods: A total of 32 patients with single tooth loss in the maxillary aesthetic area were included in the study(13 males,19 females,age range 20-53 years).Patients were included according to the following criteria: Intact socket walls;No acute infection at the site;The availability of bone apical and lingual to the socket to provide primary stability(≥35N · cm);stable occlusal relationship.All patients received the same treatment procedure,that is,a 3shape intraoral scan was used before surgery to obtain digital impressions(baseline),minimally invasive extraction of the affected teeth,flapless surgery,implants were implanted on the side of the alveolar socket,and A low substation rate bone replacement material(DBBM)was implanted in the gap,and a screw-retained temporary restoration was worn at the same time.CBCT was used to measure the size of the jumping gap.All patients were divided into three groups A,B,and C according to the size of the jumping gap.A: HDD ≤ 2mm;B: 2mm <HDD ≤ 3mm;C: HDD> 3mm.Intra-oral scans were performed again in 1 month,3 month,6 month after operation to obtain digital impressions,which were uniformly output as STL format files.Geomagic studio 2013 was used to quantitatively analyze the linear changes in the contour volume of the soft tissue around the implant,the level of the labial gingival margin,and the profile of the soft tissue contour.The pink esthetic score(PES)was used to evaluate the final aesthetic effect.Results: All implants are osseointegration at 6 months after operation.The average thickness of soft tissue contours was 0.62 ± 0.15 mm,the gingival mucosa recession was 0.42 ± 0.12 mm,and the linear changes at 1mm,3mm,and 5mm below the gingival margin were 0.29.± 0.09 mm,0.38 ± 0.11 mm,0.50 ± 0.14 mm,the average pink esthetic score was 11.09 ± 0.99.The changes of gingival mucosa levels in the three groups at 6 months after operation were 0.45 ± 0.11 mm,0.40 ± 0.12 mm,and 0.35 ± 0.11mm(P = 0.315).The changes in the average thickness of the soft tissue contour volume in the three groups at 6 months after operation were: 0.77 ± 0.16 mm,0.63 ± 0.17 mm,0.54 ± 0.11mm(P = 0.02).The linear change at 1mm below the gingival margin at 6 months after surgery was 0.35 ± 0.08 mm,0.29 ± 0.11 mm,0.24 ± 0.06mm(P = 0.066),and the linear change at 3mm below the margin was 0.47 ± 0.04 mm,0.38,respectively.± 0.12 mm,0.31 ± 0.09mm(P = 0.023),and the linear changes at 5mm below the edges were 0.64 ± 0.05 mm,0.50 ± 0.14 mm,0.40 ± 0.10mm(P = 0.005).There was a moderate negative correlation between the jumping gap size and the gingival mucosa level,the average thickness change,and the linear changes at 3mm and 5mm below the gingival margin.There was no significant correlation between the jumping gap size and pink esthetic score,the linear change at 1mm below the gingival margin.Conclusion: Within 6 months after Immediate implant placement and restoration of the maxillary anterior teeth,there was a continuous decrease in the volume of the labial soft tissue contour,with an average thickness change of 0.62 ± 0.15 mm,and the change was concentrated in the first three months(81.12%).The gingival mucosal level of patients with different jumping gaps showed a small amount of recession,and the linear measurement of the soft tissue contour profile found that the largest change was 5 mm below the gingival.Intraoperative jumping gap size and the average thickness of the soft tissue volume contour change,the gingival mucosa level,and the linear changes in the soft tissue contour profile of 3mm and 5mm below the gingival margin have a moderately negative correlation,while there was no significant correlation between the size of the jumping gap and pink esthetic score,the linear change of the 1mm soft tissue contour profile under the gingival margin.Therefore,sufficient jumping space should be reserved as much as possible during immediate implant placement of the maxillary anterior tooth area,which can reduce the contour change of soft tissue around the implant.In general,the Immediate implant placement and restoration procedure of the maxillary anterior teeth can achieve satisfactory aesthetic results,and the soft tissue level around the implant can be well maintained.