Preliminary Study On Eliminating Of Black Triangle In Implant Esthetic Area By Bicon Implant System

Objective: To evaluate the esthetic effect by using the integrated abutment crown(IAC)of the Bicon implant system to eliminate the esthetic“Black Triangle” through changing the inserting path in the case of simulated abnormal restoration of right maxillary central incisor in the esthetic implant area,aiming to provide theoretical guidance for eliminating “Black Triangle”in clinic.Methods: Part 1: Resin models were made for experimental group and control group respectively,which both right maxillary central incisor loss was simulated.In each group 10 integrated abutment crowns were made in accordance with 10 different-sized edentulous areas due to different heights of alveolar bone loss and different depths of adjacent teeth undercut.10 crowns of the experimental group could be inserted into the adjacent teeth undercut area rotatively,while the conventional 10 crowns of control group along the long axis of the implant.Scores were given to the two groups based on the Pink Esthetic Score(PES)and White Esthetic Score(WES)and analyzed statistically.Part2: One extracorporeal resin model of maxillary dentition was made for the Bicon group and the Dentium group respectively,both simulating right maxillary central incisor loss.For each group,10 different-sized edentulous areas were simulated according to varied heights of alveolar boneloss and depths of adjacent teeth undercut.In the experimental group,10 custom abutments were made with the Bicon implant,while 10 with the Dentium implant in control group.Visual Analogue Scale(VAS)was adopted to evaluate the esthetic effect after inserting the IAC into the adjacent teeth undercut from the labial side with an angle.Results: Part 1: 10 integrated Bicon abutment crowns could be rotatively inserted into the adjacent teeth undercut,with a score of 7.90±1.37 in PES and 8.00±1.33 in WES,while the10 of control group 5.00±1.33 in PES and 8.50±0.97 in WES.Compared the two groups with t test,the disparity in PES had its statistical significance(p<0.05).Among the five indicators of PES,the experimental group got higher scores than control group in terms of mesial gingival papilla,distal gingival papilla,and the degree of curvature of gingival margin on the labial surface(P<0.05),while there were no significant difference statistically between two groups in terms of the height of the gingival margin on the labial side,swell on the root surface,and the color of soft tissue(P>0.05.In WES,there was no significant difference in the scores(P>0.05).Part2: The score of the Bicon group totaled 73.45±11.19 in VAS,while the Dentum group74.80 ± 10.26,with no statistical significant difference(P>0.05).When it came to severe deficiency of soft and hard tissues and greater range of depth of the adjacent teeth undercut,IAC of both implant systems could not eliminate“Black Triangle” completely by inclining inserting.However,IAC made with the Bicon system through rotative insertion be adopted in cases like severedeficiency of soft and hard tissues and greater range of depth of the adjacent teeth undercut,even with higher VAS scores.Conclusion: Bicon implant can eliminate the “Black Triangle” in the esthetic area of anterior teeth implant and reach a better esthetic effect.