An Improved Connective Tissue Flap Transposition Technique On Alveolar Ridge Crest For Aesthetic Implant Restoration In Maxillary Anterior Zone

BackgroundsThe maxillary anterior zone is often called aesthetic region for implant restoration and the way to improving aesthetic results has attracted increasing attention. The contour, color, volume of peri-implant soft tissues have great impact on the aesthetic results. Before second-stage surgery, the patients who has been impanted in maxillary anterior zone often present a labial flat or concave profile because of the bone resorption and osseointegration. Currently, the frequently used technique of soft tissue augmentation in clinical is palatal roll technique invented by Scharf and Tarnow. This technique can augment soft tissue effectively but the shortcomings make it hard to be widly used. Based on the palatal roll technique, we finnally designed an improved connective tissue flap technique by making different incision and connective tissue flap.ObjectiveTo evaluate the effect of improved connective tissue flap technique applied in alveolar ridge crest for aesthetic implant restoration in maxillary anterior zone.MaterialMethodsA total of 20 patients with flat or concave profile of labial soft tissue on implant site before second-stage surgery who received the improved connective tissue flap technique during second-stage surgery were enrolled as the experimental group; 20 patients according with the inclusive criteria who received second-stage surgery without the improved connective tissue flap technique were involved as the control group. We observed and measured the convex profile on the facial aspect, relative height of gingival papilla and pink esthetic score at the follow time point:before surgery; 2 weeks,1 month,6 months and 12 months after surgery. The Data were analyzed with Friedman test, Wlicoxon signed-rank test, t-test and repeated measure.ResultsThe Friedman test showed statistically significant differences among the five groups in experimental group (x2(2)=52.705; df=4; P<0.001) and non-significant differences among the five groups in control group (x2(2)=5.726; df=4; P=0.221). Repeated measure shows the variety of convex profile from TO to T4 were different between expreimental group and control group. The convex profile was improved after second-stage surgery in experimental group (The measured value of T1-TO is 0.3, T2-T0 is 0.27, T3-T0 is 0.26 and T4-T0 is 0.26). The data has significant difference in comparison with control group (The measured value of T1-T0 is 0.08, T2-T0 is 0.06, T3-T0 is 0.10 and T4-T0 is 0.06) (p≤0.001). Both long-term and short-term effects were satisfactory. The change of relative height of gingival papilla and PES has no significant difference between experimental group and control group (P>0.05).ConclusionThe improved connective tissue flap technique can be considered an effective method to augment the soft tissue during second-stage surgery and it would not cause the shrinkage of gingival papilla or decrease of PES. It is worth wide application in soft tissue aesthetics of implant therapy.