Evaluation of Peri-Implant Bone Loss Around Platform Switching and Non Platform Switching Implants: A Randomized controlled trial

This study was conducted to evaluate the peri-implant bone loss around platform switching and non platform switching implants. The study was designed as a randomized controlled split mouth clinical trial for a period of 12 months. The study population comprised of 10 subjects and 20 sites. Group A consists of 10 sites, in which non platform switching implants was placed (Control sites) and Group B consists of 10 sites, in which platform switching implants was placed (Test sites). Clinical parameters such as width of keratinized gingiva, thickness of the peri-implant mucosa, papilla index, soft tissue index, probing pocket depth were evaluated. Radiographic evaluation of peri-implant bone loss was also analyzed. AIMS AND OBJECTIVES: 1. To assess if any significant correlations exists between the width of keratinized mucosa, thickness of the peri-implant mucosa, papilla index, soft tissue index, probing pocket depth around platform and non platform switching implants. 2. To evaluate and compare peri-implant bone loss around platform and non platform switching implants. MATERIALS AND METHODS: This study was designed and conducted by the Department of Periodontics, JKKN Dental College and Hospital, Komarapalayam, to evaluate clinically and radiographically the peri-implant bone loss around platform switching and non platform switching implants. This study was designed as a randomized controlled split-mouth trial. Ten patients with bilaterally missing mandibular posteriors to be restored with implant supported single crowns, were consecutively enrolled. A coin toss was utilized to randomize the implant placed in the patient. A total of 20 implants were placed. The test implants were integrated with a concept of platform switching and control implants with non platform switching design. Peri-implant crestal bone levels were standardized by radiovisiography prior to surgery. Implants were purchased from Norris implant (Norris Medical Ltd. Headquarters and R&D center, Israel) and the trade name for platform switching is Tuff TT implants and non-platform switching is Tuff implants. RESULTS: Platform switching seems to reduce peri-implant crestal bone resorption and increase the long-term predictability of implant therapy. The width of keratinized gingiva, the probing pocket depth and Soft tissue index in platform switching showed statistically significant difference when compared to non platform switching. The thickness of peri-implant mucosa and Papilla index showed no statistically significant difference between the groups. CONCLUSION: Based on the results obtained from the present study there was a minute refinement in clinical parameters, with a marked reduction in the peri-implant bone loss when platform switching implants were placed compared to the traditional non platform switching implants

Optical Impression in Restorative Dentistry

Intraoral scanners are responsible for data acquisition in digital workflow, which represents the first step in restorative dentistry. The present chapter aimed to investigate the various methods for acquiring oral information, diverse clinical applications based on optical impression technique, use of intraoral scan data according to the need for model, and the various considerations regarding the selection of intraoral scanners suitable for clinical goals. The acquired optical impression data can be sent anywhere in the world, which offers the advantage of overcoming any temporal or spatial constraints. The purpose of this chapter is to understand digital workflow using optical impression and to learn how to use it effectively in clinical practice

Evaluation of outcome of single mandibular molar tooth replacement by two narrow diameter dental implants

AIM: The aim of the present study was to evaluate the outcome of replacement of single mandibular molar tooth with two narrow diameter implants in terms of evaluation of implant success rate, bone loss, soft tissue and hard tissue healing, oral hygiene maintenance, patient satisfaction and complications. MATERIALS AND METHODS: The study was conducted in the Department Of Oral and Maxillofacial Surgery, Ragas Dental college, Tamilnadu. Patients of either sex, having partial edentulism in the posterior mandibular arch who required preferably implant based fixed prosthesis were included in this study. Patients who were willing to undergo the double implant supported molar replacement, were included in this prospective study. After preoperative evaluation, two narrow diameter implants were placed parallel to each other under local anesthesia. All the patients underwent two stage implant protocol. Implants were loaded with screw retained metal ceramic prosthesis after three months of healing. Bone loss was measured using standard intra oral periapical radiograph which were taken periodically at six months and one year post operatively. The implant success were evaluated using International congress of oral implantology’s (ICOI) criteria, implant mobility index. Pain was assessed with visual analogue scale, and post-operative oral hygiene was evaluated using modified plaque index and bleeding index. The overall satisfaction of the implant procedure was evaluated using a standard questionnaire. RESULTS: Ten patients having partially edentulousness in either mandibular first or second molar area had replaced with twenty narrow diameter implant. The average mesio-distal length of the edentulous space is 12.5mm ± 1mm, average buccolingual width is 6.3mm ± 0.7mm. All 20 implants placed were of 3mm diameter and the length of the implant ranged from 10 mm to 13 mm depending on the available length. Post-operative crestal bone loss at six month follow up (T1) was 0.52± 0.13mm, 0.57± 0.12mm for mesial and distal implant. Post-operative crestal bone loss at 12 month follow up (T2) was 1.05± 0.20mm, 1.08±0.23mm for mesial and distal implant respectively. Comparison of crestal bone loss at 6 months and 12 months was done using paired t test and it was statistically significant( p value >0.05) for mesial and distal implant. Comparison of crestal bone loss between mesial and distal implants at 6 months and 12 months is not statistically significant (p value <0.05).These measurements were made with the help of intra oral periapical radiograph film. Soft tissue and hard tissue wound healing was good in all our patients except in two patients who had mild gingival hyperplasia over the healing abutment. All the implants were successful as evaluated by ICOI criteria. 90% of all our patients had only mild or no pain at one year follow up. All our patients had a score of < 1 in the modified plaque and bleeding index indicating good oral hygiene. CONCLUSION: In our study all our mandibular molar tooth replaced with two narrow diameter supported implant prosthesis had 100% success rate, with good soft tissue and hard tissue healing and good oral hygiene maintenance at one year follow up. None of our patients had either implant fracture or abutment screw loosening or any other complications. Therefore, the use of two narrow diameter implants to replace a single molar is a logical treatment solution to avoid prosthodontic complications

Alveolar Ridge Preservation in the Sheep Model

Abstract Post extraction remodelling of the alveolar ridge results in significant reduction in the width of the ridge, which may preclude the placement of dental implants. Alveolar ridge preservation (ARP) procedures have been shown to reduce these changes, and thus are desirable, especially when the buccal plate is partially missing. Bovine-derived xenografts with porcine collagen membrane (BX) are considered the “gold standard” against which novel ARP materials should be compared. Four equine collagen products developed for ARP were tested: membrane (CM), cone with/without biphasic phosphate particles (CC, CO), and cone with integrated membrane (CS). Objectives To compare four novel products against BX in a novel sheep mandibular extraction socket model with standardised buccal defect. Methodology In 11 animals, mandibular premolars were extracted and standardised 5x2 mm buccal dehiscence defects were created. The sockets were grafted (Latin-square allocation) with BX, CC, CS, CO, CO+CM or ungrafted control (CON). The animals were euthanised after 16 weeks. Socket healing, new bone formation and reduction in the alveolar ridge width were analysed in undemineralised sections. Results No distinctive pattern of healing was noted for any of the materials. BX particles were partially resorbed by osteoclast-like multinuclear cells. Remnants of equine collagen-based products were not observed. BX grafted sites, compared to CON, showed a threefold decrease in reduction of the alveolar ridge width (p=0.002). Width preservation achieved by equine collagen products compared to non-grafted controls was not statistically significant, however better results were observed in groups CS and CO+CM. Conclusion A challenging extraction socket model with buccal defects representative of a “real-life” clinical situation was created. The test materials did not preclude new bone formation and were completely resorbed during the healing period, whereas BX-grafted sites have shown only partial resorption of the graft. The test materials, unlike the “gold standard” BX, were unable to demonstrate significant width preservation, although the results suggested that barrier membranes play an important role in ARP procedures

Clinical and Radiological Evaluation of Flapless Delayed Loading Versus Conventional Delayed Loading of Implants in Partially Edentulous Patients: One Year Randomized Prospective Follow Up Study.

The study was designed and conducted in the Department of Periodontics, JKK Nattraja Dental College and Hospital, Komarapalayam, Tamilnadu. In this one year, study was done to evaluate the clinical and radiological parameters of 5 flap and 5 flapless single tooth implants in respect to the method of placement. All the patients were followed up for 6 and 12 months corresponding to a functional loading time of 4 months. All the implants were remained in function during one year after the crown restoration. The Plaque index, soft tissue index, probing depth, width of keratinized mucosa, thickness of peri-implant mucosa, papilla index and peri-implant bone loss were recorded at baseline, 6th and 12 months intervals. The periimplant bone loss was assessed by using RVG by sopro imaging software. The data were subjected to statistical analysis. From the results obtained, the following conclusions were arrived: 1. Single tooth implant revealed higher success rates in both groups with positive tissue response. 2. The minimum 1mm thickness of peri-implant mucosa is needed for maintaining the implants without recession. 3. Peri-implant inflammation was less for implants surrounded by more than 2mm of keratinized mucosa in both groups. 4. Improved papilla fill was observed in flapless group than in flap group. 5. Average peri-implant bone loss in both groups was less than 1.5 mm after the 12 year period of function .bone loss is much lesser in flapless group comparing to flap group. 6. Pocket probing depth also lesser in flapless group comparing to flap group. The results obtained here clearly demonstrated that self-threaded internal hex, titanium implants placed according to a flap or flapless surgical protocol can be predictably successful over a period of 12 months. High successful rates were achieved without severe peri-implant complications. However, it is necessary to have a large sample size with proper selection of the patients needed to evaluate the clinical and radiological parameters. Also further studies need to be carried out to evaluate the relationship between peri-implant soft and hard tissue in respect to the placement of implants

Osseointegrated Oral implants

In the past, osseointegration was regarded to be a mode of implant anchorage that simulated a simple wound healing phenomenon. Today, we have evidence that osseointegration is, in fact, a foreign body reaction that involves an immunologically derived bony demarcation of an implant to shield it off from the tissues. Marginal bone resorption around an oral implant cannot be properly understood without realizing the foreign body nature of the implant itself. Whereas the immunological response as such is positive for implant longevity, adverse immunological reactions may cause marginal bone loss in combination with combined factors. Combined factors include the hardware, clinical handling as well as patient characteristics that, even if each one of these factors only produce subliminal trauma, when acting together they may result in loss of marginal bone. The role of bacteria in the process of marginal bone loss is smaller than previously believed due to combined defense mechanisms of inflammation and immunological reactions, but if the defense is failing we may see bacterially induced marginal bone loss as well. However, problems with loss of marginal bone threatening implant survival remains relatively uncommon; we have today 10 years of clinical documentation of five different types of implant displaying a failure rate in the range of only 1 to 4 %