Biostatisticians are masked to the implant abutment biomaterial designations (masked as "A" and "B") during data analysis. Initial bivariate analysis using the Wilcoxon-Mann-Whitney (Wilcoxon Rank Sum) test will be employed to assess the difference in distribution between the two groups (titanium dioxide or zirconium oxide) for each cytokine/bone mediator and for age. The same approach is used to consider whether a gender difference was associated with a particular cytokine/bone mediator. Gender distribution in the two groups will be compared using the Fisher exact test. The Spearman rank correlation will be used to assess the possibility of a relationship with age for each cytokine. Rank-based regression models will be used to adjust for possible effects of age and gender for both cytokine and bone mediator levels.