Evaluation of the effect of different connective tissue donor sites on peri-implant tissues in immediate implantation

Aim: To evaluate dimensional changes of soft and hard tissues around implants that are treated with connective tissue graft (CTG) harvested from different sites in immediate tooth replacement. Material and methods: Twenty subjects required tooth extraction due to endodontic or restorative problems were included. Twenty teeth located in between maxillary second premolar were randomized in test (n=10) and control (n=10)groups. Following the atraumatic tooth extraction, drilling was performed without flap elevation and implants were then placed. The gap formation between implant and buccal bone were filled with alloplastic bone graft. Temporary restoration was fabricated either with the autogenous tooth or composite material and screwed onto the implant. Split-thickness undermining tunnel was prepared at the buccal aspect of the implant site, test site received CTG obtained from tuberosity and control site received it from palate. Cone beam computed tomography (CBCT) was used to evaluate dimensional hard tissue changes. Soft tissue changes were evaluated with images (1:1 ratio) and clinical measurements. Images were recorded at baseline and 6 month. CBCT images were recorded at 1 week and 6 month. Soft tissue thickness measurements were performed apical to the mucosal margin using an acrylic stent containing 3 different slots with 1mm interval. Dimensional changes in buccal bone were measured at 0, 2, 4mm apical level to the implant shoulder. Vertical bone level changes were measured as a distance from implant platform to crestal bone. Pain levels in the donor site were assessed using VAS scale. Parametric tests were used in the evaluation of inter/intra-group comparisons. Statistical analysis were performed using α = 0.05 level. Results: Study was completed with 20 implants. Buccal bone thickness changes were not statistically significant between test and control groups at baseline and 6 months (p>0.05). Crestal bone level changes between baseline(2.37mm) and 6-months (1.90mm) were statistically significant in the control group (p<0.05). Buccal soft tissue thickness in both groups were found superior compared to baseline and statistically significant (p<0.01). These changes were not statistically significant between two groups (p>0.05). Inter/intra-group comparisons in buccal and interproximal soft tissue levels were not statistically significant (p>0.05). Donor site pain levels at test group were found inferior and differences were statistically significant (p<0.01). Pain levels in the control group were decreased faster. Conclusion: Immediate implant placement with individualized temporary restoration and CTG cannot prevent soft and hard tissue dimensional loss. However, CTG obtained from tuberosity could minimize the extent of the crestal bone loss. Besides, CTG harvesting from tuberosity may increase the patient comfort associated with lower pain levels.