Immediately loaded mandibular implant bar overdenture: a surgical and prosthodontic rationale

Classical guidelines for osseointegration include a long healing time, during which functional load should be avoided. However, the long healing period might impose an intolerable situation on some patients, especially in the completely edentulous situation. Studies on immediately loaded implant-supported prostheses in completely edentulous patients have been reported, exhibiting high success rates comparable to conventionally loaded implants. This article describes the surgical and prosthodontic procedure for the immediately loaded mandibular implant bar overdenture as well as its clinical rationale.     

Treatment outcomes in implant therapy: the influence of surgical and prosthodontic experience.

In this retrospective study reviewing 30 months of treatment, 53 partially or completely edentulous patients were provided with implant-supported restorations. The restorative aspects of the therapy were undertaken by an experienced prosthodontist who had just begun involvement with implant rehabilitation techniques. Patients were treated in two centres, 21 in a major teaching institution (Group A) and 32 in a private practice (Group B). In Group A, the implants were placed by experienced oral and maxillofacial surgeons just beginning involvement in implant techniques. The implants of the Group B patients were placed by surgeons with a minimum of 2 years implant experience. It appeared that the surgeon's experience had a major impact on the failure probability of unloaded implants. Loading conditions and the design of the prosthesis may be the decisive determinants for the probability of success with loaded implants. The hazards of extensive cantilevered extensions were demonstrated. The results suggest that those entering implant prosthodontics should not expect their early work to match the results obtained from established centres.     

Implant complications and failures: the complete overdenture

The implant-retained overdenture has been advocated as an effective method of restoring the edentulous patient with an appliance that offers significant benefits over conventional prosthetics. However, the success and survival of such appliances have been shown to vary considerably, depending on which jaw is treated: implants supporting overdentures in the maxilla have a significantly higher failure rate. The restoration also requires considerable maintenance, which is both time consuming and costly. The purpose of this paper is to look at common restorative complications and maintenance problems following the placement of dental implants to support an overdenture. A number of implant systems have been reviewed and the results of the authors' clinical experiences with referred and their own cases are reported.     

Attachment systems for implant overdenture: influence of implant inclination on retentive and lateral forces

Objective: To evaluate the retentive force and lateral force of an implant with various types of attachments for overdentures in relation to implant inclination. Material and methods: An implant (3.75 × 13 mm) was embedded into an acrylic resin block, simulating the edentulous ridge. Four different attachment systems were used, including: (1) Locator black and blue, (2) a ball attachment, (3) a flat‐type magnetic attachment and (4) a self‐adjusting magnetic attachment, which has vertical and rotational movement. All of the attachments were under a constant dislodging force with an angle of the implant at 0°, 15°, 30° and 45°, and the experiments were repeated 10 times using a universal testing machine to measure the retentive force. The lateral force to the implant was measured by strain gauges attached on the implant surface. Statistical analysis was performed by multiple comparisons with Bonferroni's correction. P<0.05 was considered statistically significant. Results: At 0°, the significantly highest retentive force was observed in the Locator blue, followed by the Locator black, ball, flat‐type and self‐adjusting magnetic attachments. The Locator blue and ball attachment maintained the retentive force until a 30° inclination; however, the lateral force increased significantly, especially with the ball attachment. The retentive force of the magnetic attachment was significantly lower at 0°, as well as the lateral force in the self‐adjusting magnetic attachment. Conclusion: Within the limitations of this study, we conclude that the retentive force decreases with an increase in implant inclination, whereas the lateral force increases, except for in magnetic attachments. To cite this article:
Yang T‐C, Maeda Y, Gonda T, Kotecha S. Attachment systems for implant overdenture: influence of implant inclination on retentive and lateral forces.
Clin. Oral Impl. Res. 22 , 2011; 1315–1319.
doi: 10.1111/j.1600‐0501.2010.02137.x     

Effects of implant angulation, material selection, and impression technique on impression accuracy: a preliminary laboratory stu

The aim of this preliminary laboratory study was to evaluate the effects of 5- and 25-degree implant angulations in simulated clinical casts on an impression's accuracy when using different impression materials and tray selections. A convenience sample of each implant angulation group was selected for both open and closed trays in combination with one polyether and two polyvinyl siloxane impression materials. The influence of material and technique appeared to be significant for both 5- and 25-degree angulations (P < .05), and increased angulation tended to decrease impression accuracy. The open-tray technique was more accurate with highly nonaxially oriented implants for the small sample size investigated.     

A simple, predictable intraoral technique for retentive mechanism attachment of implant overdenture attachments

A technique is presented for intraorally attaching two O-ring attachments to a mandibular complete denture. The technique involves fabricating and placing a mandibular denture with conventional procedures. Patients adapt initially to the complete denture. The attachments are then attached to the denture base with autopolymerizing acrylic resin. This technique provides a predictable method to achieve a tissue-supported and implant-retained overdenture.     

Implant overdenture using a locator bar system by drill and tapping technique in a mandible edentulous patient: a case report

Various options have been introduced for the selection of implant overdenture attachments. Attachment wear due to the repeated insertion and removal of dentures has caused problems such as decreased retention and the requirement for suprastructure remanufacturing. In these cases, a Locator bar system was applied using the drill and tapping technique to achieve total retrievability. In a 55-year-old female patient who showed three degrees of mobility in most of her teeth due to severe alveolar bone loss, a complete denture in the maxilla and an implant supported type overdenture in the mandible were planned after extracting all the remaining teeth. Six implants were placed from canine region to the distal molar region, and the locator was connected to the milled bar using the drill and tapping technique. For a 61-year-old female edentulous patient who complained of poor retention with old denture, a complete denture in the maxilla and an implant-tissue supported type overdenture in the mandible were planned. Four implants were placed in front of mental foramen, and the Locator was also connected to the Hader bar using the drill and tapping technique. With this technique, female parts can be easily replaced, and retention can be continuously maintained.     

Mandibular implant overdenture treatment: Consensus and controversy

A literature review of implant overdenture treatment for the edentulous mandible is presented. The report focuses on the knowledge base for this treatment modality, in an effort to distinguish between areas that are well characterized and enjoy a higher level of consensus among practitioners as compared with those that are more controversial and not clearly understood.     

Repair of a milled cantilevered implant overdenture bar: a clinical report

This clinical report of a fractured cantilevered substructure bar describes an alternative treatment to the proposed refabrication of the substructure bar and overdenture prosthesis. This report outlines the clinical and laboratory procedures to repair the fractured bar, eliminating the time and expense of fabricating a new bar and prosthesis.     

Maxillary insufficiency implant and tooth-retained maxillary overdenture: a clinical case report

The following represents a clinical case report of a maxillary insufficiency implant and tooth-retained maxillary overdenture. The case required surgical and prosthetic treatment and was successfully completed over a 2-year time. A combination of dental implant techniques were utilized to achieve form, function, comfort, and aesthetics. These techniques included ridge modification with bone grafting, endosseous root and blade form implant surgical placement, and the construction of a bar-retained overdenture on a severe hypoplastic maxilla.     

Laboratory procedures for the maintenance of a removable partial overdenture

Laboratory procedures in support of maintenance therapy for a typical patient with a removable partial overdenture were described. These procedures consisted of the fabrication of a gold metal coping and the reline of the prosthesis with autopolymerizing acrylic resin. In designing the coping contours, the technician must consider the path of insertion of the prosthesis and the space requirement for the overlying resin tooth. Reproduction of the dowel preparation is facilitated by using a plastic dowel as part of the coping wax pattern. The removable partial overdenture was relined with autopolymerizing acrylic resin in a reline jig. Tooth-colored acrylic resin was used in the concavity formed by the overdenture abutment to enhance esthetics. The requirement of a coordinated effort between the dentist and the dental laboratory technician is critical to the successful treatment of the removable partial overdenture patient.     

Attachment of clips in a bar-retained maxillary implant overdenture: a clinical report

Implant-supported overdentures are a good alternative for patients with conventional dentures that lack retention and stability. The most common prosthetic complications in mandibular and maxillary implant-supported overdentures are fracture and loosening of the attachment system. This clinical report describes the treatment of a completely edentulous patient with sinus floor elevation by using bone from the iliac crest and the insertion of 4 implants in the maxilla and mandible followed by implant-supported overdentures. The technical procedure for the attachment of clips to an acrylic resin overdenture base with the use of metal reinforcement is described. The advantage of this attachment procedure is an improved attachment system with less fracture and less loosening of the clips.     

Atraumatic surgical technique and implant bed preparation.

The issues of bone necrosis and implant bed congruency are both central to the success or failure of endosseous dental implants to achieve osseointegration. Use of internally irrigated drilling instruments has been postulated to minimize bone necrosis. The ability of the cutting instruments to produce a smooth, congruent implant bed and retain fine bone structures is also critical to achieving primary integration. In the experiment conducted, the use of internally cooled instruments reduced the likelihood of thermal bone damage, particularly when trephine mills were used. Trephine mills were able to retain the fine bone structures of the walls of the implant bed site. No visible degradation occurred from multiple uses of the instruments.     

Use of the integral implant for overdenture stabilization

This paper describes the surgical and restorative use of the Integral endosseous implant for overdenture stabilization with different types of retentive attachments. The clinical experiences of 90 overdenture patients with follow-up to 56 months postrestoration are discussed. With proper patient work-up, failure and morbidity has remained low.