## 4 Discussion  
The results from this descriptive pilot study of 37 implants showed that immediate provisional restoration (out of occlusion, with final restoration and loading within two weeks) of titanium dental implants with surfaces enhanced with PTTM were clinically effective, with a 5-year survival rate of 97.2%. As a comparison to non-TM systems, a recent systematic review and meta-analysis of 18 dental (non-TM) implant studies evaluated the 10-year survival of contemporary, two-piece titanium systems; the summary estimate for 10-year survival at the implant level was 96.4% (95% CI 95.2-97.5%) [11]. Professional consensus in dental implantology affirms that the success of implants is dependent on the presence and preservation of surrounding bone, particularly in the crestal area; however, a primary challenge of dental implant treatment is the bone resorption, particularly saucerization, that occurs after insertion [12]. Results from the present study showed an initial mean bone loss of 0.40 mm (SD = 0.48) after 6 months and minimal bone level changes over time up to 5 years in function. While the small sample size of this uncontrolled study limits direct comparisons to findings in other studies, these findings suggest that crestal bone loss around TM implants is lower than traditional titanium implant systems [13,14], and that the unique properties of PTTM may foster enhanced vital bone and surrounding tissue ingrowth and potentially reduce the amount of bone remodeling which occurs during the first year following implant surgery [15]. A recent 1-year retrospective case-control study by [PERSON] et al. reported a 0.28-mm mean bone gain in a TM implant cohort, and multivariate logistic regression analysis demonstrated that the odds of having bone loss were 64% less in a TM group compared to a non-TM implant control group [16]. Another recent study by [PERSON] et al. compared osteogenesis gene expression in a small group of patients who had received both TM and non-TM implants; the authors found that, compared to traditional titanium alloy, trephine samples from the TM implant group displayed higher expression of genes specific to neovascularization, growth factors, and osteogenesis [17]. To further contextualize these crestal bone level changes when compared to non-TM implants, contemporary literature was surveilled for studies with similar sample sizes and follow-up periods. An analysis by [PERSON] et al. found that a cohort of 24 patients with 40 screw-type (non-TM) implants that were immediately provisionalized in molar and premolar sites experienced an overall survival rate of 95% at 5 years, with significant marginal bone loss (1.06 mm) in the first year [18]. To compare the crestal bone findings in this report with historical standards, longitudinal studies on the original Branemark implant showed that one year after abutment connection, crestal bone loss frequently extended 1.5 mm to 2 mm below the implant-abutment junction [19]. This became the unofficial industry standard for acceptable crestal bone loss because most major implant systems experienced a similar bone loss phenomenon during the early years of their products. However, more contemporary implant surfaces typically include a rougher surface to foster better osseointegration, as improving the roughness of an implant surface has been correlated with less peri-implant bone loss [2]. Additionally, because the abutment was immediately placed with no intention of removal during the follow-up period, essentially the \"one abutment/one-time\" method was used in this study. The abutment was secured not only by the fixation screw, but also with a friction-fit connection. This type of \"one-piece\" implant has been shown to have less initial bone loss [20]. The TM implants used in this study have a PTTM shell that begins about 4.5 mm apical to the implant platform. A recent report by [PERSON] et al. compared osteogenic activity between titanium and TM-coated implants in a nonclinical study of rabbits.