Comparison Between Two Different Design Concepts of 4- Implant Assisted Mandibular Complete Overdenture:- periimplant bone height changes

Purpose: This study was accomplished to evaluate the bone height changes radiographically and the reliability of use either two posterior short or inclined implants with two conventional anterior implants retaining mandibular overdenture. Materials and methods: Ten male mandibular completely edentulous patients were divided in two equal groups after delivered complete dentures. For the first group (short implant design- group A) two vertical implants were inserted in the canine areas and two short vertical implants were inserted in the 1st molar area. For the second group (inclined implant design- group B) two vertical implants were inserted in the canine areas and two 30o distally inclined implants were inserted in the second premolar area. Digital standardized periapical radiographic assessment for horizontal and vertical alveolar bone height changes was carried out at T0 (immediately), T6 (6 months), T12 (12 months) and after mandibular complete overdenture insertion. Result: 1. VBL decrease significantly with advance of time in both groups during the time intervals. The highest VBL around the implants was noted in the 1st six months followed by the 2nd six months, the highest amount of total VBL observed with the interval T0-T12, followed by the interval (T0-T6) and the inclined implant group showed significant higher total VBL than short implant group at the intervals T0-T6 and T0-12. 2- HBL decreased significantly with advance of time in both groups. For short and inclined implant group, the highest amount of total HBL observed with the interval T0-T12, followed by the interval (T0-T6). Short implant group showed significant higher total HBL than inclined group at the interval T0-T6 and T0-T12. Conclusion: Within the limitations of this clinical radiographic study it can be concluded that (1) The 30o distally inclined implants inserted in the posterior areas for assisting mandibular complete overdenture induce vertical bone loss more than the axially inserted implants (short or conventional implants). (2) The short implants inserted in the posterior areas for assisting mandibular complete overdenture induce horizontal bone loss more than the axially inserted implants. Keywords: Short implants, O-ring ball attachment, VBL, HBL.

Immediate Post-Extraction Short Implant Placement with Immediate Loading and without Extraction of an Impacted Maxillary Canine: Two Case Reports

For the treatment of impacted maxillary canines, traction associated with a complete orthodontic treatment is the first choice in young patients. However, in adults, this treatment has a worse prognosis. The surgical extraction of the impacted tooth can result in a series of complications and a compromised alveolar bone integrity, which may lead to the requirement of a bone regeneration/grafting procedure to replace the canine with a dental implant. These case reports aimed to describe an alternative treatment procedure to the surgical extraction of impacted maxillary canines in adults. Following clinical and computerized tomography-scan (CT-Scan) examination, the possibility of maintaining the impacted canine in its position and replacing the temporary canine present in its place with a dental implant was planned. A short dental implant with an immediate provisional crown was placed, without contacting the impacted canine. At 3 months follow-up, a definitive metal-ceramic restoration was placed. Follow-up visits were performed periodically. The implant site showed a physiological soft tissue color and firmness, no marginal bone loss, no infection or inflammation, and an adequate aesthetic result in all follow-up visits. These results suggest that the treatment carried out is a valid option to rehabilitate with an osseointegrated short implant area where a canine is included, as long as there is a sufficient amount of the remaining bone.

Synthetic Putty and Simultaneous Short Implant Placement in Crestal Sinus Lifting Procedures: 13–36 Months Follow-Up: A Case Series

Introduction: Aim of this investigation is to show that in sites with less than 4 mm of bone height of the sinus floor, synthetic putty bone graft and simultaneous short implant placement in crestal sinus lifting procedures result in sufficient bone gain, and is a valuable option to the more invasive lateral-window approach. Case presentation: Four patients missing a single tooth or more in the posterior maxilla with remaining alveolar ridge height of less than 4mm underwent crestal sinus lift procedures with bone grafting using a synthetic putty material simultaneously. Loading of the short implants was done with a minimum of 4 months after placement showing bone growth around the implant and lift of the Schneiderian membrane between 2.3mm-7.3mm. Conclusion: Crestal sinus lift, in combination with a short implant and a synthetic putty bone graft, is a good alternative for lateral more invasive sinus lift when the thickness of the sinus floor is less than 4mm.

Different Treatment Modalities Using Dental Implants in the Posterior Maxilla: A Finite Element Analysis

The objective of this study was to compare the biomechanical behavior of peri-implant bone tissue and prosthetic components in two modalities of treatment for posterior region of the maxilla, using short implants or standard-length implants associated with bone graft in the maxillary sinus. Four 3D models of a crown supported by an implant fixed in the posterior maxilla were constructed. The type of implant: short implant (S) or standard-length implant with the presence of sinus graft (L) and type of crown retention: cemented (C) or screwed (S) were the study factors. The models were divided into SC- cemented crown on a short implant; SS- screwed crown on the short implant; LC- cemented crown on a standard-length implant after bone graft in the maxillary sinus and LS- crown screwed on a standard-length implant after bone graft in the maxillary sinus. An axial occlusal loading of 300 N was applied, divided into five points (60N each) corresponding to occlusal contact. The following analysis criteria were observed: Shear Stress, Maximum and Minimum Main Stress for bone tissue and von Mises Stress for the implant and prosthetic components. The use of standard-length implants reduced the shear stress in the cortical bone by 35.75% and the medullary bone by 51% when compared to short implants. The length of the implant did not affect the stress concentration in the crown, and the cement layer acted by reducing the stresses in the ceramic veneer and framework by 42%. Standard-implants associated with cemented crowns showed better biomechanical behavior.