Evaluation of the effects of different groove length and thickness of the retainers on the retention of maxillary anterior base metal resin bonded retainers ' an in vitro study

Objectives: The resin-bonded fixed partial dentures have gained immense popularity in recent years as they are more conservative, esthetic, economic and easily fabricated. However debonding is considered the most common cause of failure of resin bonded prosthesis. The objective of the study were to compare the effects of different groove lengths and thickness of retainers on retention of maxillary anterior base metal resin bonded retainers. Study Design: Twenty five metal dies of maxillary central incisor duplicated from pure typhodont teeth (maxillary left central incisors) prepared to receive retainer for resin bonded fixed partial denture having different test designs were made. Five test groups were made with each group having five specimens. Two groups were having preparation depth of 0.5mm and retention groove lengths of 3mm and 5mm. Two groups had preparation depths of 0.3 and 0.7mm with no groove preparation with retainer thickness of 0.3 and 0.7mm respectively. Fifth group with no groove preparation and preparation depth of 0.5mm was kept as control for all the groups. All the specimens were cemented using calibra (Dentsply) resin cement. Each specimen was subjected to tensile loading in vertical direction on universal testing machine (Instron 5569) at a crosshead speed of 1mm/min. \ Results: Groups with 5mm and 3mm groove length recorded higher mean vertical forces when compared to the group with no groove preparation. Group with 5mm groove length showed highest mean vertical forces. The group with 0.7mm retainer recorded higher mean vertical force values when compared to groups with 0.5mm and 0.3mm retainer thickness. Group with 0.3mm retainer thickness recorded the least mean vertical force value. Conclusion: Placement of the grooves increased the retention values almost 2 ½ times than the grooveless preparation and as the thickness of the retainers increased retention values also increased. Retention value was directly proportional to the groove length and retainer thickness

Reconstruction of a midfacial defect using an intraoral-extraoral combination prosthesis employing magnets: a clinical report

Radical maxillectomy frequently leads to extended defects in hard and soft tissues that result in a connection between the oral cavities and orbit. If the defect cannot be surgically reconstructed, a combination prosthesis may be necessary to remedy dysfunction in patient function, comfort, esthetics. For minor defects, enlargement of the base of the intra oral prosthesis is generally sufficient. Resections that affect more than one third of the maxilla usually require an intra oral and an extra oral prosthesis that could be assembled and retained in the patient. This clinical report describes a technique of prosthetic rehabilitation of midfacial defect with a silicone orbital prosthesis and intra oral obturator that are retained by magnets

Accuracy of the implant impression obtained from different impression materials and techniques: review

With the predictable integration of implants, the emphasis is shifted towards precise prosthesis. Reproducing the intraoral relationship of implants through impression procedures is the first step in achieving an accurate, passively fitting prosthesis. The critical aspect is to record the three dimensional orientation of the implant as it is present intraorally, other than reproducing fine surface detail for successful implant prosthodontic treatment. The development of impression techniques to accurately record implant position has become more complicated and challenging. During the prosthetic phase of implant therapy there are numerous options available to the implantologist in relation to different impression techniques and materials available for impression making. It is critical to ensure that implant – prosthesis interface have passive fit and original position of the implant maintained in the master cast. There is no evidence supporting that one impression technique or material is better than the other. In the present article the various parameters affecting the accuracy of implant impression along with impression material and technique pertaining to different clinical situations is reviewed

Extraction and immediate placement of root analogue zirconia implants: an overview

Dental implants constitute a well-established approach for replacement of lost teeth with titanium being the most favored material for implantation. However, titanium has its limitations in esthetically demanding cases and neither the form nor material of such implants has changed much over the past 40 years. Immediate implantation has been introduced to overcome the disadvantages of conventional implantation which in turn has many disadvantages owing to the incongruence of the implant to the extraction socket. Today, there is scientific evidence that zirconia dental implants osseointegrate well and offer many advantages over titanium implants. The successful use of zirconia ceramics in orthopedic surgery led to a demand for dental zirconium-based implant systems. Because of its excellent biomechanical characteristics, biocompatibility, and bright tooth-like color, zirconia (zirconium dioxide, ZrO2) has the potential to become a substitute for titanium as dental implant material. In addition, there are previous reports on the successful use of Zirconia as root-analogue implants by reproducing the contours of the extracted tooth. This article presents an overview of the technique of using root analogue zirconia dental implants as an immediate implantation material which are replicas of the extracted tooth and therefore truly anatomical and socket friendly

Combined surgical and prosthetic approach for rehabilitation of frontonasal defect using custom made titanium implant: a case report

Cranial vault deformities as a sequelae to trauma may be as high as 70%. The basic indications for cranioplasty are improvement of disfigured aesthetics and to provide protection to the intra-cranial contents. The possibility of producing custom-made implants opened a new era in the reconstructive surgery of the craniofacial deformities. The outcome of craniofacial bone reconstruction is thought to be dependent on surgical skills, quality of adjacent soft tissues, size and location of the bone defect and choice of repair method. The use of autologous bone for craniofacial reconstruction may be restricted due to limited amounts of donor bone. Combined surgical and prosthetic rehabilitation of these structures utilizing craniofacial implants is a viable option which offers several advantages when compared to surgical reconstructive techniques alone. Predictability and superior aesthetics are the major advantages of this technique. In addition to the advantages of good biocompatibility and mechanical strength, titanium also provides the advantage of being light in weight. This clinical report highlights the combined surgical and prosthetic approach for the successful management of frontonasal defect

Finger prosthesis using silicone elastomer: A novel methodology

Maxillofacial prosthodontics is much an art as it is a science. The prosthesis provides a life-like appearance to duplicate the missing structures. The complete or partial loss of a fi nger not only results in functional deficiency, but also causes marked psychological trauma to the patient. This paper describes the fabrication of custom made finger prosthesis using silicone material. The retention for this patient was obtained by reducing the stump and using a ring of suitable size

Denture camp: An experience beyond imagination

Main aim of dental camp is awareness, education, and motivation of the common man regarding his/her dental health. This report presents the efficient way of conducting a denture camp and tackling the short comings faced during the course. When treating a vast population in camps, it calls for more number of instruments, equipments and lot of manpower in terms of doctors, dental mechanics and supporting staff. 110 patients were selected for the denture camp. They were informed to come early morning at 8a.m on the scheduled date and make necessary arrangements for their stay for one night during the camp as the most of the patients were from surrounding villages. Dentures are no more a luxury; it has become a necessity for the edentulous patients for the basic health maintenance. Many problems were encountered during this camp. Though there were so many hurdles doctors became successful in treating the patients. The team had taken a brave step with all the problems and they ended successfully. In spite of all the problems faced, the dedicated team work proved fruitful in rehabilitating 132 patients in short spans 24 hrs. The efforts of team were highly appreciated by the people

The Evolution of External and Internal Implant–Abutment Connections: A Review

A study of the implant–abutment connection is of great importance because it is the primary determinant of the strength and stability of an implant-supported restoration, which, in turn, determines the restoration’s prosthetic stability. Traditionally, Brånemark’s external hexagon has been used, but significant complications, such as abutment screw loosening, rotational misfit at the implant–abutment interface, and microbial penetration have led to modification of the external hexagon and the development of internal implant–abutment connections. In this review, we describe various implant–abutment connections that have evolved over time from the traditional external hexagon. &#x0D; How to cite this article: Alharissy M, Dayoub S. The Evolution of External and Internal Implant–Abutment Connections: A Review. Int Dent Res 2012;2:37-42.&#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.</jats:p