[Year:2014] [Month:January-April] [Volume:5] [Number:1] [Pages:12] [Pages No:12 - 23]
Conventional techniques of full arch/full mouth implantation works on placement of implants and leaving them undisturbed for subgingival healing until they get osseo integrate into the jaw bone. These implants are uncovered after the subgingival healing of 3 to 6 months depending on various factors, such as bone density, implant dimensions, occlusal load, etc. and res tored in function once the soft tissue has healed in next 3 to 4 weeks. The vertical ridge loss along with maxillary sinus pneumatization restrict the clinician to place adequately long implants into posterior maxilla without performing sinus augmentation procedures. Further, many patients who have the chronic sinus pathologies do not qualify to receive the sinus graft and refused by the dentists for the fixed implant prosthesis. Uncontrolled diabetics are also not good candidates for the sinus grafting. In the implant dentistry, such patients have simply been treated with the implant over dentures by avoiding posterior maxilla. In the similar fashion, the vertically resorbed posterior mandible has also been a big challenge for the implant dentists in the cases where the dentist find insufficient bone dimensions to place even shortest available implants above the mandibular canal. In implant dentistry, various procedures, such as onlay block grafting, nerve repositioning, etc. have been advocated to manage the resorbed posterior mandible. Such procedures are more invasive, require multiple surgical steps, elongate the treatment time and also cause the tissue morbidity to some extent. Moreover, the full mouth work is not very simple in most cases because most of edentulous patients do not step in with adequate bone dimensions in all four parts of the jaws to place implants with adequate dimensions. Conventional way of treating edentulous patients with full mouth implant supported fixed prosthesis may require placement of multiple number of implants, bone augmentation procedures, longer treatment span and multiple number of surgical steps. Thus, such techniques are not always comfortable and also affordable to the patients. In comparison to the posterior segments, anterior parts of the jaws offer the bone with larger volume and higher density which enables the dentist to place longer implants with higher initial stability by stabilising implant apices into the opposing cortices/ basal bone (nasal floor, mandibular symphysis). In this tilted implant concept, the back implants are slanted distally to place the implant head at the second premolar or first molar position which enables to place longer implants, stabilizing their apices into the anterior higher density bone, and reduces the distal cantilever of the prosthesis. Total four implants are used in this technique where two straight implants are placed close to the midline and rest two implants are placed anterior to the maxillary sinus (in maxilla) or mental foramina (in mandible) which are slanted distally to reach the second premolar or first molar position. A 10 to 12 unit screw-retained metal to plastic (hybrid) splinted prosthesis is placed over these implants. Hence, it is a graft less implant placement procedure for restoring the edentulous jaws by tilting posterior implants for utilizing maximum amount of bone and stabilizing them into highest possible bone density. This facilitates an optimal support for an acrylic prosthesis that can be immediately fixed over the inserted implants to restore the esthetics and functions within few hours after the implant insertion surgery. This paper aims to explain the graft less approach for full arch immediate rehabilitation on 4 to 6 implants placed in one arch by smartly tilting the back implants to avoid vital structures, such as maxillary sinus and mandibular canal and stabilizing into the high density bone. This clinical study was done on total 80 implants to evaluate their success under the tilted positioning and immediate load conditions. The technique was performed on both diabetic and nondiabetic patients and no variation was found on the success rate between both the groups. None of the tilted implant got failed in 3 years follow-up but four implants got failed at anterior positions which immediately replaced with new implant placed at the adjacent position and restored in function. The mean values of bone loss relative to the implant platforms at 1 year follow- up were 0.8 mm for the maxilla and 0.5 mm for the mandible. The average bone loss for the maxilla and mandible respectively, at 3 years of follow-up were 1.3 mm. Thus, very promising results were found in this clinical study. Hence, the conclusion is that the tilted implant immediate function concept for completely edentulous patients has proven to be clinically effective technique, patient pleasing and applicable in various clinical situations where otherwise more invasive, complicated and expensive bone augmentation procedures would have been indicated.