Influence of titanium base, lithium disilicate restoration and vertical soft tissue thickness on bone stability around triangular-shaped implants: A prospective clinical trial

ObjectiveTo evaluate how vertical mucosal tissue thickness affects crestal bone stability around triangular-shaped bone-level implants, restored with low profile titanium bases and monolithic lithium disilicate restorations. Material and methodsFifty-five bone-level implants of 4.3mm diameter were evaluated in 55 patients (22 males and 34 females, mean age 48.33.4years) in prospective cohort study. According to vertical mucosal thickness, patients were assigned into three groups: 1 (thin, 2mm or less), 2 (medium, 2.5mm) and 3 (thick, 3mm and more). Implants were placed in posterior mandible and maxilla in one-stage approach and, after integration, were restored with single screw-retained monolithic lithium disilicate crowns, using low gingival profile titanium bases. Radiographic examination was performed after implant placement and after 1-year follow-up. Crestal bone loss was registered mesially and distally, and mean value was calculated. One-way ANOVA and Tukey's HSD tests were applied; significance was set to 0.05. ResultsMean vertical tissue thickness in 1 group was 1.76 +/- 0.26mm, 2 group-2.5mm and 3.91 +/- 0.59mm in group 3, with statistically significant difference between all groups (p<0.001). After 1-year follow-up, implants in group 1 (thin) had 1.25 +/- 0.8mm bone loss. Implants in group 2 (medium) had 0.98 +/- 0.06, while implants in group 3 (thick) lost 0.43 +/- 0.37mm of crestal bone. Tukey's HSD test showed that differences between 1/3 and 2/3 were statistically significant (p<0.001 and p=0.0014, respectively), while between 1 and 2 was not significant (p=0.310). ConclusionsSignificantly less bone loss occurs around triangular-shaped bone-level implants in thick mucosal tissues (3mm), compared to medium or thin tissue biotype. Crestal bone loss did not differ between medium and thin tissues.