# Long-Term Prosthetic Aftercare of mandibular Implant-Supported Overdenture
## 1 Introduction  
Complete edentulism remains a substantial problem inflicting the quality of life of millions of dental patients worldwide. Its prevalence may reach values as high as 14.4% in young age groups and 32.3% in older age groups. Unfortunately, it is also associated with depression and poor self--related health [1]. The obsolete treatment modality of a conventional mandibular complete denture has lost its position as the primary standard of care for that predicament. The use of two endosseous dental implants placed in the anterior mandible as an aid to support and retain complete mandibular dentures proved itself an effective and predictable treatment option [2]. It has been favored as the primary standardof care for treating mandibular edentulism for almost twenty years [3]. The therapy of a maxillary complete denture with mandibular implant-supported overdenture (MISOD) among totally edentulous patients is a well-documented and successful treatment modality with proven patient satisfaction and chewing performance [4; 5]. One of the research foci concerns the attachment systems that convey the load to the implants and the supporting tissues. A large systematic review concerning prosthetic aftercare with MISOD summarized in one of its conclusions that the implant attachment system has no clear effect on prosthetic aftercare requirements [6]. A more recent Cochrane review investigating prosthetic and patient-related outcomes of different attachment systems for maxillary and mandibular overdentures revealed deficient data to compose any meta-analyses due to the non-uniformity of included studies. Accordingly, that review concluded that there was insufficient evidence to support improved performance and outcomes of any specific attachment system [7]. A popular and simplified treatment philosophy encourages using two separate implants to support/retain a mandibular overdenture due to anatomical restraints, chair time, cost, and oral hygiene limitations [8; 9]. Marginal bone loss (MBL) around implants is another important issue. With time, there seem to be slightly shallower probing depths around separate implants supporting an overdenture in comparison to splinted implants after 10 years of function. In addition, healthy mucosal conditions and stable marginal bone levels (determined radiographically) were found [10]. Another study comparing implant manufacturers found significantly less MBL around Straumann implants in comparison to Branemark implants over a five-year observation period [11]. These two studies [10; 11] refer to MISOD on two separate implants. A meta-analysis showed that splinting implants through any specific attachment system does not offer any advantage concerning implant survival, marginal bone loss, and prosthetic complications [12]. However, the findings of the present systematic review should be analyzed with caution due to other influencing factors such as implant number/position, connection type, length/diameter, loading protocol, and follow-up period [12]. Two of the most popular resilient attachment systems available today are locator and ball attachments. Their comfortable ease of repair and installation on both implants and the supported overdenture made them highly acceptable among practitioners. In a recent meta-analysis, mean marginal bone loss was reported comparable between the locator attachment and the ball anchor [13] after a minimum of 1 year follow-up period. The same was true for an immediate and delayed loading protocol. Peri-implant clinical parameters, as well as patient satisfaction, yielded no significant difference between the attachment systems in a clinical study [14]. Another study repeated the non-significant difference in aftercare requirements between the groups [15]. On the other hand, [PERSON] et al. found more aftercare requirements and less retention with the locator system versus ball attachments. A significantly higher plaque score was noted in the locator group [16].