# Complete Full Arch Supported by Short Implant (<8 mm) in Edetulous Jaw: A Systematic Review
## 1 Introduction  
Nowadays, the use of a conventional full arch for the treatment of edentulous patients is a common treatment approach [1]. Often due to severe vertical and horizontal resorption of the alveolar ridge, complications such as lack of stability and reduced masticatory function are often associated with lower full dentures. To improve mechanical and esthetic function, the use of mandibular full-arch restorations (fixed or removable) supported by conventional implants in the interforminal region has advanced, which have achieved a predictable mode with high success rates (87% to 100%) [1,2]. However, maxillary resorption due to periodontal disease and vertical and horizontal bone loss can reach a severity that prevents or even limits conventional implant rehabilitation treatments. In addition, sovereign anatomical structures such as the inferior alveolar nerve can be irreparably damaged when using conventional length implants [3]. To overcome these situations, the literature often proposes more invasive techniques for the clinician to refer to, such as vertical bone augmentation [4], osteogenic distraction [4], and lateralization of the inferior alveolar nerve [4]. However, limiting elements such as dental phobia, morbidity in the postoperative period, economic costs, and treatment difficulty may negatively influence the patient in wanting and being able to accept implant therapy [5]. Recently, some systematic scientific reviews and clinical studies have shown that the use of short implants results in low failure and complication rates and, most importantly, have found minimal marginal bone loss for single and partial restorations supported by short implants placed in the mandible. Recent studies have shown that the use of tissue-level implants in patients with severe bone atrophy appears to be a viable option when applied in the rehabilitation of the entire immediate loading interval [6]. However, we still lack sufficient evidence on the durability of full-arch prosthetic restorations supported by short implants (<8 mm) incompletely dedentulous and severely resorbed mandibles [7; 8]. On the other hand, Group 1 of the Sixth ITI Consensus Conference, analyzing the definition of \"short,\" determined that \"short dental implants\" are all dental implants \(\leq\) 6 mm in size [9]. Today, scientific evidence from several clinical studies in the literature found no statistically significant differences in implant survival rates or observed no changes in marginal bone loss (MBL) of short dental implants compared to standard-length dental implants. Often, the combined use of short implants and bone regeneration techniques may result in less surgical complexity [9]. Other studies have shown that when more discrepancy in crown-to-implant ratio is present, the more this increases the risk of mechanical problems, but the risk of peri-implant marginal bone loss does not increase. Another important aspect to evaluate and consider is the area of implant installation, because the likelihood of failure increases when implants are installed in low-density bone, such as in the maxilla in the posterior region [8; 9; 10; 11; 12; 13]. However, there is no consensus on the short-term survival rate of implants in the posterior maxilla and mandible [10]. Some authors have advanced limited success rates, while others have found high success rates for short implants placed in the maxillae [10; 11; 12].  
The purpose of this study was to systematically review the literature regarding implant survival rates, marginal bone levels, and the prosthetic success of full-arch short dental implants used for the rehabilitation of severe mandibular atrophy.