Introduction: Narrow alveolar ridges especially in posterior mandibular remains a serious challenge for successful placement of endosseous implants. Case Presentation: This case report addresses surgical procedures for widening the atrophic ridge by means of splitting the crest of an edentulous ridge as thin as 2.5 mm and gradual expansion in the posterior mandibular ridge, then simultaneous placement of dental implants within the split ridge. A significant increase was achieved in the bone dimension, which enabled the placement of endosseous dental implants successfully. Discussion: This segmental ridge-split procedure with gradual bone expansion provides a quicker method wherein an atrophic ridge can be predictably expanded and eliminating the need for a second surgical site. This technique also shows that immediate implantation in split ridge of mandible can be performed.

Context:A key determinant for clinical success is the diagnosis of the bone density in a potential implant site. The percentage of boneimplant contact is related to bone density, and the axial stress contours around an implant are affected by the density of bone. Evidence Acquisition: A number of reports have emphasized the importance of the quality of bone on the survival of dental implants. The volume and density of the recipient bone have also been shown to be determining criteria to establish proper treatment plans with adequate number of implants and sufficient surface area. Previous clinical reports that did not alter the protocol of treatment related to bone density had variable survival rates. To the contrary, altering the treatment plan to compensate for soft bone types has provided similar survival rates in all bone densities. Results: When bone density decreases and bone become softer, the implant surface in contact with the bone decreases, therefore treatment plan should be modified by changing the drilling protocol, using gradual loading and reducing the force on the prosthesis or increasing the loading area with increasing implant number, implant position, implant size, implant design (deeper and more threads with more pitch, squared shape) and implant body surface condition. Conclusions: Once the prosthetic option, key implant position, and patient force factors have been determined, the bone density in the implant sites should be evaluated to modify the treatment plan. Inappropriate implant number or design in poor quality bone results in higher failure rates. Changing the treatment plan and implant design is suggested, based on bone density to achieve higher survival rates.Keywords:Bone Density; Dental Implant; Implant Design Implication for health policy/practice/research/medical education: Providing the long-term survival rate and higher success rate of dental implant in poor bone quality/Ideal treatment planning based on making proper decisions; make a selection based on a scientific approach, rather than on advertising or marketing opinion.

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Background: The minimum standard treatment plan for the reconstruction of an edentulous mandible, according to York, is an overdenture supported by two implants. Objectives: The aims of this study were to evaluate and compare the clinical outcomes and peri-implant marginal bone loss around implants in patients treated with mandibular overdentures supported by 1, 2, 3, 4, and 5 implants. Materials and Methods: A total of 25 patients with a mean age of 62.7 years old, who were treated with implant supported mandibular overdentures at Hamedan's faculty of dentistry, were enrolled in this cross-sectional study. Among these patients, 6 had overdentures supported by one implant, 9 had overdentures supported by two implants, 2 had overdentures supported by three implants, 5 had overdentures supported by 4 implants, and 3 had overdentures supported by 5 implants. The clinical and radiographic parameters around the implants were assessed, including: probing depth, width of keratinized gingiva, bleeding on probing, peri-implant inflammation, calculus formation, implant mobility, adverse events, and radiographic signs of peri-implant bone loss (distance between the implant shoulder and the level of the mesial and distal proximal bone). The ANOVA and the Fisher's Exact test were used to evaluate the significant differences among the groups. Results: None of the implants had loosened and no adverse events were seen around the implants. Additionally, the clinical variables did not show significant correlation with the number of implants. Overall, the bone resorption showed an inverse and significant relationship with the number of implants (P = 0.001). Conclusions: With mandibular overdentures supported by 1, 2, 3, 4, and 5 implants, favorable clinical outcomes can be achieved. However, when increasing the number of implants, marginal bone loss decreases. For example, the patients with five implants showed less marginal bone loss than those with a lesser number of implants.