## 1 Introduction  
Currently, rehabilitation with dental implants is an effective therapeutic option for the replacement of missing teeth in patients with partial or total edentulism. For this to be achieved, the success and survival of these implants must be ensured, with one crucial factor being sufficient bone availability to bear functional loads [1; 2; 3]. The loading forces which occur during chewing have been shown to require implants of sufficient length, within 8-10 mm for the premolar and molar regions in both the mandible and the maxilla, these being generally accepted as standard measurements [4; 5].  
Given that patients frequently present with bone defects of variable characteristics as a result of various processes such as tooth loss, which leads to an average 40-60% decrease in horizontal and vertical bone loss of the alveolar crest during the first year, periodontal disease, trauma, tumors, and cysts, the correct three-dimensional placement of implants often becomes complicated [6; 7; 8; 9; 10]. Because of this, various surgical techniques have been proposed, such as onlay-inlay bone grafts, distraction osteogenesis, inferior alveolar nerve transposition, split crest, guided bone regeneration (GBR), and maxillary sinus augmentation [11; 12; 13; 14; 15].  
This last procedure, which is one of the most used in implant practice, arises from the need to rehabilitate the posterior maxillary areas which are often atrophic due to the prevalence of type IV cancellous bone and to dental extractions which cause rapid vertical and horizontal resorption, in many cases accompanied by increased preamatization of the sinus in these areas [12; 13; 14; 15; 16]. This procedure was first described by [PERSON] et al. in 1965,becoming popular in the 1980s. In it, the Caldwell-Luc procedure was used to access the sinus. [PERSON], for his part, popularized the crestal approach together with the use of osteotomes and bone grafts, a procedure which is considered less invasive [16; 17; 18].  
Although the sinus lift procedure can be considered clinically predictable, it is not exempt from complications such as the dispersion of graft material in the sinus cavity, wound dehiscence, hematomas, migration of implants inside the sinus, fenestrations, oronantl fistulae, epistaxis, bone sequestration, acute sinusitis, and perforations of the Scheiderian membrane [19; 20; 21; 22]. This last complication is considered the main drawback of this procedure, occurring in 10-35% of cases where the direct method is used, with an approach through the lateral wall of the maxillary sinus [23; 24]; or in 25% of cases with an indirect approach through the alveolar crest and where the initial bone height lay between 3 and 6 mm [25; 26; 27; 28]. Elevation of the mucosa of the maxillary sinus inevitably causes stretching of the tissue which, in cases of higher elevations, may easily lead to tearing and perforation of the sinus membrane [29]. A retrospective study reported similar findings: the highest rates of perforation were correlated to higher elevations. These perforations often lead to contamination of graft tissue and to the subsequent loss of both the graft and the implants [30; 31].  
The present study based on maxillary sinus lifts was performed on ex vivo bisected pig heads, employing a new device for the balloon technique patented by the author. The study was justified by the need to assess the efficacy of this new system, which is proposed as both a more conservative technique for the elevation of the Schneiderian membrane, and a novel procedure which currently has no articles proving its reliability. The study aims to assess the feasibility of the device, describe the technique, and contrast its advantages and disadvantages.