Joanne N. Walton

Problems with prostheses on implants: a retrospective study.

Prosthetic parameters for implant success have not been well defined but should include patient satisfaction and prosthesis maintenance, including adjustments and repairs. In addition, differences between fixed and removable implant-supported prostheses (ISPs) should be quantified. This study retrospectively evaluated both patient satisfaction and maintenance for 156 patients. Removable ISPs averaged almost three times as many adjustments per prosthesis (2.1 versus 0.8 per fixed ISP) and more than twice as many repairs (1.9 per removable ISP versus 0.9 per fixed ISP). The most common adjustments were to the contour of both types of prosthesis, and the most frequent repairs involved the retentive clips with removable ISPs and the gold screws with fixed ISPs. The incidence of repeat repairs was more than twice as high with removable prostheses compared with fixed prostheses. However, the repairs to opposing dentures most often needed were for conventional dentures opposing fixed ISPs. The vast majority of repairs were needed within the first year of service. Despite the high maintenance needed, patients were satisfied with both types of ISP, with the exception of limited satisfaction with cleansability, particularly with fixed restorations. The high incidence of early repairs, and the greater potential for a removable ISP requiring adjustment and repair, should be considered both when discussing options with the patient and when estimating treatment and maintenance costs before the commencement of implant therapy.

Altered sensation associated with implants in the anterior mandible: A prospective study ☆

STATEMENT OF PROBLEM Reported incidences of altered sensation after placement of mandibular implants range from a low of 0% to almost 44%, making it difficult to advise subjects regarding risk. PURPOSE This study involved presurgical and postsurgical assessment of sensation in the lips and chins of 75 subjects, all of whom objectively demonstrated normal sensation before surgery. MATERIAL AND METHODS Objective and subjective tests were administered before, and at planned intervals for 12 months after, the placement of 2 implants in the anterior mandible. RESULTS Objective changes were observed in only 1 subject and then only at the 2-week postsurgery interval. There were significant differences for all subjects in subjective sensation changes from baseline to 2 weeks after surgery (P =.007) and from 2 weeks to 6 months (P =.003) or 12 months (P =. 003). There was a higher percentage of subjects with normal sensation before surgery who reported sensory changes 2 weeks after implant placement (34% vs 24% for all subjects), but only 1% of subjects still reported altered sensation 1 year later. Although there were no significant differences between men and women in reports of altered sensation, more women than men noted sensation changes 2 weeks after implants were placed (25% vs 13%). There appeared to be no relationships among gender, the degree of ridge resorption, and reports of altered sensation. CONCLUSION Thus, although approximately 24% of subjects may report altered sensation in the short-term after implant surgery in the anterior mandible, the problem appears to be a transient one, with only about 1% experiencing sensation changes 1 year after implant surgery.

The economics of complete dentures and implant-related services: A framework for analysis and preliminary outcomes☆☆☆★★★♢

It is not always clear that the implant-prosthesis offers distinct advantages over the conventional complete denture for managing the edentulous jaw. This article discusses the measurement, distribution, impact, and management of the edentulous jaw, and describes a framework for analyzing the economic costs and benefits associated with the conventional denture and the implant prosthesis. There are physiologic and psychosocial costs and benefits to both the conventional denture and the implant prosthesis, which indicates that neither method is distinctly superior. The physiologic costs are low and the psychosocial costs are similar for both treatments, whereas the direct financial costs associated with the implant prosthesis are substantially higher.

In vitro changes in clips and bars used to retain implant overdentures

Although implant-retained overdentures are a less expensive alternative to fixed implant-supported prostheses in certain situations, problems with retentive clips fracturing and needing frequent replacement have been reported. This study compared baseline and posttest retention of metal and plastic clip-retained overdenture analogs and monitored surface changes in bars and clips throughout the testing process. A laboratory model was made with two implant analogs processed into an acrylic resin platform to which three bars were fitted. Two overdenture analogs were made and retained on the model with metal or plastic clips. Each bar-clip assembly was subjected to 5500 insertion and removal cycles to simulate 3 years of in vivo insertion and removal. Although the differences in retention between metal and plastic clips and between clips before and after testing were statistically significant, it is questionable whether they are clinically significant. Neither clip fracture nor loss occurred during this study, which suggests that it may be functional or parafunctional loading and not repeated insertion and removal of an implant overdenture that may cause the stated problems.

Apical root strain as a function of post extension into a composite resin core

This study tested the hypothesis that there is no difference in the amount of strain measured in the root of an extracted tooth at the apical end of a prefabricated post, whether a composite resin core completely covers the head of the post or the post is exposed at the occlusal surface of the core. Twenty extracted teeth were measured (1) after endodontic treatment (baseline), (2) after a composite resin core was fabricated over a prefabricated post, and (3) after a cast crown was cemented. The teeth were randomly divided into two groups after baseline testing. In group 1, the post was buried within the core, and in group 2, the head of the post was exposed on the occlusal surface of the core. Analysis of results indicated a statistically significant decrease in strain from the baseline to the crown when 1 mm of composite resin covered the head of the post. However, based on the small strain values measured, the difference may not be clinically significant.

Panoramic radiographs made before complete removable dental prostheses fabrication: A retrospective study of clinical significance

Statement of problem. The value of digital panoramic radiographs to screen for problems before fabricating conventional complete dentures is unclear. Purpose. The purpose of this retrospective study was to examine the influence of pretreatment digital panoramic radiographs on the clinical management of patients receiving complete removable dental prostheses. Material and methods. The clinical records, including panoramic radiographs, of 169 patients seeking new complete removable dental prostheses over a 6‐year period were interpreted independently by both a prosthodontist and an oral and maxillofacial radiologist to identify radiographic findings that influenced clinical patient management. A 95% confidence interval and an observed proportion of agreement were used to interpret the results. Results. Sixty percent of the 169 radiographs examined had 1 or more abnormal or positive radiographic findings; however, only 6 (<4%) of 165 abnormalities detected influenced patient management, and 3 of them were identified during the clinical examination. Conclusions. Pretreatment digital panoramic radiographs revealed very few abnormalities that influenced the treatment of patients requiring complete removable dental prostheses. Furthermore, the digital images in this study revealed positive findings at a rate similar to those found in studies assessing analog radiographs, reinforcing current guidelines that recommend against radiographic screening of patients who seek new complete removable dental prostheses.