PES in relation to buccal plate thickness and jumping distance: A 8 year cohort retrospective study

4BS98 ePOSTER CLINICAL RESEARCH – PERI-IMPLANT BIOLOGY

Background: Guidelines for predictable long-term esthetic success for the challenging anterior zone in case of post extraction implant placement have considered multiple factors. The correlation of some of these factors especially the buccal bone thickness and jumping distance have been independently assessed as well. The purpose of this 8 year follow-up study has been to compile and analyze the interplay of gingival biotype and these factors to predict long-term esthetic results.

Aim/Hypothesis: To study the Pink Esthetic Score on restored anterior immediate extraction implants in a delayed protocol; considering pre-existing surgical and biological factors: buccal bone thickness, jumping distance and gingival biotype.

Materials and Methods: Data of Xive implants placed in fresh extraction sockets in a single dental practice where delayed loading protocol was followed and which had complete post cementation records (up to 8 years) were included in the study. Records of patient's medical history, radiographs, gingival biotype, surgeon's notes at the time of implant placement for protocols followed for atraumatic extraction and immediate implant placement, buccal bone thickness measurement, measurements of distance between buccal bone and implant surface at the time of implant placement were obtained. Photographic records taken at baseline (1 year post cementation), and recall at 4 years and 8 years were analyzed for Pink Esthetic Score. Weighted score was allocated to the 3 peri-implant variables Biotype, Bone thickness and jumping distance and peri-implant status was thus defined. Association between PES and average bone thickness, jumping distance or peri implant status were found by Chi square test.

Results: For thin Biotype (N = 54), the minimum and max PES were 5 and 11, and for thick biotype (N58), these values were 7 and 14, respectively. The median PES for thin biotype was 8 and for thick it was 11. Spearman's rank correlations suggest a significant moderate positive correlation between PES and average bone thickness (Rho = 0.66) and a strong relationship between PES and jumping distance (Rho = 0.814). Chi square test suggests significantly higher proportion of poor PES (less than 7) when jumping distance was < =1 mm and significantly higher proportion of excellent PES (12 and above) when jumping distance was > =3 mm (P = 0.000). The proportion of good/excellent PES (12 and above) was significantly lower for average bone thickness 0.75- 1 mm. Median PES for peri-implant status poor (N43), Moderate (N42) and Good/Excellent (N 27) was 26.52, 64.01 and 92.56 respectively and the difference was statistically significant (P = 0.000) as observed by Kruskal-Wallis Test.

Conclusions and Clinical Implications: Assuming biotype is constant; jumping distance is a stronger predictor of PES as compared to buccal bone thickness provided average buccal bone thickness up to 4 mm from crest is minimum 1 mm. Periimplant variables such as gingival biotype, bone thickness and jumping distance can act as predictors of long-term esthetics and can suggest ideal implant width or additional hard and soft tissue grafting procedure requirements during the post extraction phase.

Keywords: Predictors of implant esthetics, Immediate implant placement, Buccal bone thickness, Jumping distance, Gingival biotype