| Background and objective:The goal of implant restoration in esthetic zone is to restore the coordinated gingival margin curve and gingival papilla height,and pursue harmonious pink esthetic,white esthetic and contour esthetic.Due to the special anatomical characteristics of the anterior area,the thickness of labial bone wall of 87% of patients is less than 1 mm,and the resorption of the labial bone wall after tooth extraction is twice that of the palatal side.Therefore,different implantation opportunities are proposed.Immediate implant placement is implant placed in fresh extraction socket after tooth extraction.This requires an intact bone wall greater than 1 mm on the labial side.Early implant placement is implant placed 4 8 weeks after tooth extraction with soft tissue healing,and guide bone regeneration to restore the soft and hard tissue morphology at the labial bone defect at the same time.Some scholars believe that immediate implant placement has a high risk of gingival margin retraction,which is closely related to the inclination of the labial side of the implant and the incorrect three-dimensional position of the implant.At present,there are relatively few studies on the changes of soft and hard tissue when the implant is in the correct three-dimensional position.By reviewing the patients with immediate and early implant placement in the esthetic zone with correct three-dimensional position of implant,this paper analyzes the changes of labial soft and hard tissue and related factors.Methods:This study included patients whose maxillary central incisor or lateral incisor trauma or failed root canal treatment treated at Oral Implantology Department of Stomatological Hospital of Jilin University between January 2016 to January 2022.They were divided into 4 groups according to different implant timing and operation methods.The basic informations of patients were recorded including the implant diameter and gingival biotype.The changes of labial gingival margin were observed to obtain the pink and white esthetic score.For each patient,preoperative and postoperative（0、6 months after sugery）CBCT imaging datas were collected to evaluate the following indicators: Labial bone wall thickness（LBWT）before operation（T1）,labial bone wall thickness（IO-1）,labial bone wall thickness（IO-5）,labial vertical bone height（VBH）,labial horizontal bone resorption（HBR-1）,labial horizontal bone resorption（HBR-5）,labial vertical bone resorption（VBR）immediately after operation（T2）and 6 months after operation（T3）,labial middle gingival margin retraction（LGMR）,pink esthetic score（PES）and white esthetic score（WES）.The biological complications and patient satisfaction of all included implants were recorded.SPSS.26 software was used for statistical analysis.Results:According to the inclusion and exclusion criteria,a total of 50 implants were collected from 41 patients,including 12 immediate implant placement and restoration（group 1）,8 immediate implant placement and delayed restoration（group 2,flapless）,11 immediate implant placement and delayed restoration（group 3,flap）and 19 early implant（group 4）.Two of the implants had fistula on the labial gingiva above the implant platform during the temporary restoration,and all implants could function normally after permanent restoration.1.The average bone wall thickness of labial neck in the four groups were 3.20 ± 0.73 mm,3.24 ± 0.66 mm,3.25 ± 0.61 mm and 3.05 ± 0.59 mm respectively.There was no significant difference among the four groups（P > 0.05）;The average bone wall thickness of the middle labial was 2.47 ± 0.82 mm,2.53 ± 0.93 mm,3.19 ± 0.81 mm and 3.52 ± 0.69 mm respectively.There was significant difference between group 1 and group 4,group 2 and group 4（P < 0.05）;The average vertical bone height above the labial implant platform was 1.90 ± 0.67 mm,1.88 ± 0.85 mm,1.87 ± 0.59 mm and 1.92 ± 0.54 mm respectively,there was no significant difference among the groups（P > 0.05）.2.Six months after operation,the average bone wall thickness of labial neck in the four groups were 2.42 ± 0.66 mm,2.26 ± 0.56 mm,2.46± 0.93 mm and 2.35 ± 0.69 mm respectively.There was no significant difference among the four groups（P > 0.05）;The average bone wall thickness of the middle labial was 2.00 ± 0.73 mm,1.96 ± 0.82 mm,2.59± 0.95 mm and 3.06 ± 0.79 mm respectively.There were significant differences between group 1 and group 4,group 2 and group 4（P < 0.05）;The average vertical bone height above the labial implant platform was1.51 ± 0.86 mm,1.09 ± 0.77 mm,1.28 ± 0.73 mm and 1.22 ± 0.81 mm respectively,there was no significant difference among the groups（P >0.05）.3.Bone resorption 6 months after operation: The average bone resorption of labial neck in the four groups were 0.78 ± 0.41 mm,0.98 ±0.44 mm,0.79 ± 0.47 mm and 0.68 ± 0.47 mm respectively;The average bone resorption in the middle of the labial of the four groups were 0.47 ±0.28 mm,0.56 ± 0.29 mm,0.60 ± 0.40 mm and 0.42 ± 0.25 mm respectively;The average bone resorption of labial vertical in the four groups were 0.38 ± 0.37 mm,0.80 ± 0.49 mm,0.59 ± 0.44 mm and 0.70 ±0.69 mm respectively,there was no significant difference among the above groups（P > 0.05）.4.Changes of labial gingival margin from permanent restoration to an average of 24 months after operation: The retraction of middle labial gingival margin in the four groups were 0.067±0.26 mm,0.088±0.25 mm,0.082±0.21 mm,0.068±0.19 mm respectively,there was no significant difference among the groups（P > 0.05）.5.Gingival biotype: In immediate implant placement（groups 1,2and 3）there was no significant difference between thin and thick gingival biotype in horizontal and vertical bone resorption 6 months after operation（P > 0.05）,and there was no significant difference in gingival margin change and pink and white esthetic score 24 months after operation（P > 0.05）;In early implant placement there was no significant difference between thin and thick gingival biotype in horizontal and vertical bone resorption 6 months after operation（P > 0.05）,and there was no significant difference in gingival margin change and pink and white esthetic score 24 months after operation（P > 0.05）.6.After an average of 24 months,the total PES scores of the four groups were 8.67±1.07,7.87±0.84,8.09±0.83,8.58±0.84,and the difference between the groups was not statistically significant（P>0.05）（P > 0.05）.There was no significant difference in the total score of WES among the groups（P > 0.05）.7.Patient satisfaction survey（VAS）: Each group had high satisfaction with the implant restoration process and final restoration effect,and the satisfaction of patients in the immediate implant placement and restoration group was the highest.Conclusion:1.Under the premise of correct three-dimensional position of the implant,the ideal esthetic outcome can be obtained in the short term between immediate and early implant placement,and sufficient bone wall thickness and stable soft and hard tissue state can be obtained on the labial side.2.There was no significant correlation between the timing of implant restoration and the changes of soft and hard tissue.The emergence profile designing and soft tissue shaping of provisional restoration are very important to the position and shape of gingival margin and gingival papilla.3.The amount of immediate implant placement without flap bone graft is limited,and there is inevitable bone resorption in the labial bone wall after tooth extraction.Early implant placement can obtain a larger amount of bone graft,and can obtain more consistent bone arch contour and root convexity,its contour esthetic result may be better than immediate implant placement.4.Gingival biotype had no significant difference on the changes of soft and hard tissue around implant and esthetic outcome. |
PDF Full Text Request