Peri-implant Stress Analysis of Immediate Loading and Progressive Loading Implants in Different Bone Densities (D2 and D3): A Finite Element Study
[Year:2014] [Month:January-April] [Volume:5] [Number:1] [Pages:7] [Pages No:1 - 7]
DOI: 10.5005/JP-Journals-10012-1107 | Open Access | How to cite |
Aim: To analyze the peri-implant stress distribution in immediate loading and progressive loading implants in different bone densities (D2 and D3). Materials and methods: A 3D finite element model of a mandibular section of the bone with a missing second premolar and a crown structure was used. Eighteen models were generated, eight were used for immediate loading and the remaining ten were of progressive loading. Of the eight models of immediate loading, four models each were used for D2 and D3 bone density types. Of the ten models used for progressive bone loading, five models each were used for D2 and D3 bone density types. A solid 4.2 × 10 mm screw type implant system (Replace Select RP, Nobel Biocare) was selected. The simulated crown consisted of metal coping of Nickel-Chromium alloy, porcelain and acrylic in few models. Axial and oblique loads were applied to the implant through the crown based on the loading protocols for immediate and progressive loading. Results: Maximum stress was found in the cortical bone at the neck of the implant for both type of loading protocols except when there was no bone implant contact seen at initial stages of healing in immediate loading implants. Oblique occlusal forces show a significantly higher stress level as compared to axial loading forces. Conclusion: Both loading conditions and bone density were found to be very important factor in the stress management in implant dentistry.
Titanium Hypersensitivity: A Clinical Study
[Year:2014] [Month:January-April] [Volume:5] [Number:1] [Pages:4] [Pages No:8 - 11]
DOI: 10.5005/JP-Journals-10012-1108 | Open Access | How to cite |
Titanium implants are extensively used to replace the missing natural teeth in prosthodontics. However, allergic reactions to titanium in dentistry has not received its due attention. Literature reports sensitivity to titanium ranging from 0.6 to 5% of the general population. The allergic reactions in patients who are sensitive to titanium ranges from type I to IV with symptoms ranging from vague pain, skin rashes to implant failure. The aim of this study was to evaluate the presence of titanium allergy by anamnesis and examination of subjects using titanium dioxide 0.5% in patch test methodology. A sample size of four hundred healthy subjects with no previous history of immunosuppression were included. Titanium dioxide 0.5% concentration in petrolatum was used to conduct the patch test. A history of allergy to any other allergen was recorded as a part of the study. Under the limitations of this study, it was concluded that, titanium can induce hypersensitivity response in susceptible patients. From this study it was observed that the hypersensitivity reactions to titanium was 0.3% in all the subjects tested. It was also observed that the individuals with a prior history of allergy to other known allergens were more susceptible to allergic reactions to titanium. Limitations of the study was the absence of a wider age group of population for this study. Future research is recommended by considering a wider age group of population and a longterm followup of patients.
Tilted Implant Concept for Full Mouth Immediate Loading Restoration
[Year:2014] [Month:January-April] [Volume:5] [Number:1] [Pages:12] [Pages No:12 - 23]
DOI: 10.5005/JP-Journals-10012-1109 | Open Access | How to cite |
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.
Vascularized Interpositional Periosteal Connective Tissue Flap Technique to correct Soft Tissue Defect around Maxillary Anterior Implant
[Year:2014] [Month:January-April] [Volume:5] [Number:1] [Pages:5] [Pages No:24 - 28]
DOI: 10.5005/JP-Journals-10012-1110 | Open Access | How to cite |
The esthetic outcome of implant-supported restorations has become increasingly important, especially for single-tooth implants in the esthetic zone. Because of the morphologic alterations that occur following tooth extraction, augmentation procedures are often necessary before, during, or after implan tation to achieve an esthetically pleasing result. There are many periodontal plastic surgery procedures available to esthetically reconstruct deficiencies in both hard and soft tissues; however each technique has its own limitation. A newer technique, vascularized interpositional periosteal connective tissue flap has been introduced as an alternative to these techniques which allows the clinician to perform large volume soft tissue augmentation in esthetic sites with a single procedure. In the present case report, long-term result of soft tissue augmentation with VIP-CT flap is presented were in peri-implant recession was noted as a complication.
Demystifying the Retrievability of Cement-retained Implant-supported Restorations
[Year:2014] [Month:January-April] [Volume:5] [Number:1] [Pages:5] [Pages No:29 - 33]
DOI: 10.5005/JP-Journals-10012-1111 | Open Access | How to cite |
The field of implant prostheses has come of age in the post-Branemark era. Various research studies are being carried out world over, in order to formulate superior materials, achieve better esthetic outcomes, quicker functional results, minimal treat ment complications and maximal comfort to the patient in concern. Prosthetic reconstruction involving implants may involve screw-retained or cement-retained crowns depending upon the clinician's preference and the clinical situation. Potential unpredictable biological or mechanical complications that might occur in an implant supported prostheses make retrievability an important point of consideration and so is the treatment planning. Thus, this case report finds newer means to predict the screw access hole in cases where cement retained prosthesis is indicated.
Natural Crown as Immediate Implant Provisional Prosthesis
[Year:2014] [Month:January-April] [Volume:5] [Number:1] [Pages:4] [Pages No:34 - 37]
DOI: 10.5005/JP-Journals-10012-1112 | Open Access | How to cite |
Purpose: The purpose of this article is to describe a clinical case in which the patient's failing tooth was extracted and with minute modifications the same crown was used as provisional's after immediate implant placement. Esthetic single tooth implant placement using traditional two stage surgery or single stage in anterior maxilla is well-documented in literature. Several complications can occur in healing phase like loss of papilla, ridge resorption, tissue loss, etc. Patients own tooth with preserved crown architecture can be utilized as provisional as it may provide acceptable gingival esthetics, maintenance of interproximal contours, palatal adaptation, better tooth shape and preservation of both papilla.