T w o i m p l a n t s s u p p o r t i n g a m a n d i b u l a r o v e r d e n t u r e Fig. 8 Fig. 8 Postoperative radiograph. Discussion This prospective case series study was designed to evaluate the one-year clinical and radiograph- ic outcomes and patient satisfaction of Cawood and Howell Class V and VI patients treated with a mandibular overdenture supported by two implants using a novel low-profile retention system. Because it was designed as a single- cohort study without sample size calculation, the main limitations were the lack of a control group and a small sample size. Hence, this in- vestigation should be considered as a proof of concept for future multicenter randomized clin- ical trials with control group comparison. The results of the present one-year prelimi- nary prospective case series study reported im- plant and prosthetic survival and success rates of 100% and greater patient satisfaction, indicat- ing that patients with extremely atrophic mandi- bles (Cawood and Howell Class V and VI) may be rehabilitated using fixed-removable solution. Owing to increased life expectancy, the treatment of elderly patients is advancing in medicine. With the alveolar bone resorbed and the vertical dimension of the mandible reduced, an altered relationship to the maxilla; poor, vari- able bone for implant restoration; and loss of cheek and lip support result. According to the literature, implant-retained mandibular overden- tures can be an effective treatment option for patients who have persistent problems with conventional dentures.4 Various attachment systems have been successfully utilized to con- nect these overdentures to the implants includ- ing bar, ball, magnetic and resilient telescopic attachments.16 A relatively recent attachment that has become increasingly popular is the OT Equator low-profile direct implant overdenture attachment (Fig. 7). It is a resilient and self- aligning attachment system with stable reten- tion. Owing to its low profile, it can be used with limited interarch distance. In addition, in the present study, the low-profile OT Equator attachments were used to rehabilitate severely atrophic patients, reducing the risk of denture base fracture over time. In addition, OT Equator attachments allow for angle compensation of up to 30°, which may be helpful in severely atro- phic patients with different severities of man- dibular atrophy and lingual concavities that may compromise the ability to place axial implants without bone reconstruction. Furthermore, the new Smart Box allows passive insertion under extreme conditions, also up to 50° divergence (Fig. 8). The findings of this study support the estab- lished evidence base for improvement in eden- tulous patients’ satisfaction with their prosthe- ses when two implants are used to retain their 58 Volume 3 | Issue 2/2017 Journal of Oral Science & Rehabilitation