The Role of Abutment-Attachment Selection in Resolving Inadequate Interarch Distance: A Clinical Report

A critical factor that needs to be evaluated during the diagnosis and treatment planning phase for patients seeking an implant-tissue-supported overdenture or metal-resin implant fixed denture is the presence of adequate interarch distance. The amount of interarch distance is critical to the selection of appropriate implant abutments and attachments for both implant-tissue-supported overdentures and metal-resin implant fixed complete dentures. This clinical report describes a patient with complications related to the failure to diagnose inadequate interarch distance, and the methods used to resolve the patient's chief complaint. A guide for abutment-attachment selection using one commercially available implant system is given.     

Co-ordinated treatment of secondary cleft deformities

Secondary cleft deformities result from the cumulative effects of functional and morphological abnormalities. Treatment choices should be based on a comprehensive plan which is designed to minimize treatment time and iatrogenic effects and which is based on sound physical and psychosocial objectives. Conventional orthodontic and orthognathic surgical principles can be modified and applied to a variety of facial cleft problems. Direct surgical correction of secondary deformities instead of prosthetic or orthodontic compensation expands treatment possibilities and optimizes treatment results.     

A Comparison of an Accelerated Technique for Casting Post-and-Core Restorations With Conventional Techniques

Purpose This project compares an accelerated technique for the casting of post-and-core restorations with four traditional techniques. The accelerated technique uses two phosphate-bonded investments and the traditional techniques use a gypsum- and a phosphate-bonded investment. The study measures and compares the differences between the seating of the casting and the seating of the acrylic resin pattern. The effects of the techniques on the fit of castings with and without a ferrule are also compared. Materials and Methods Six groups of 10 castings were made from plastic patterns formed on a stainless steel test die. A different investment and/or burnout method was used for each group. Each group had two subgroups: ferruled and nonferruled. The fit of the plastic patterns was measured at two time intervals after forming, 2 weeks and 3 months. The patterns were invested immediately after the 3-month measurement, and the difference in fit of the castings was calculated. An ANOVA and Tuckey-Kramer test were done to determine the statistical validity. Results The seating of the patterns after 3 months of storage was consistently worse than the 2-week measurements of fit. The ferrule and nonferrule patterns were not statistically different in seating. Measurement of the castings showed that the ferruled castings seated significantly worse than the nonferrule castings. The difference in the seating of the castings as compared with the patterns was considered clinically unacceptable, showing a range of 0.301 mm to 0.528 mm. The nonferrule castings showed a significant difference in seating among groups. The difference ranged from - 0.099 mm to 0.322 mm. Conclusions The castings of the ferrule subgroups were considered clinically unacceptable and were not analyzed for significance. Among the nonferrule castings, the group using a gypsum investment and conventional technique for investing and burnout but no ring liner showed the best seating. The accelerated technique was intermediate in seating with a difference of 0.148 mm from the seating of the patterns. This group was significantly different from the two best groups but not from the remaining three groups.     

The Accuracy of Implant Verification Casts Compared With Casts Produced From A Rigid Transfer Coping Technique

Purpose Prosthodontic techniques for implant-supported prostheses continue to evolve in an effort to facilitate treatment and minimize costs. Because research has shown no impression transfer technique to be without error, some clinicians have attempted to control the fit of prosthetic frameworks by reorienting sections of patterns or frameworks intraorally, fabricating a verification cast, and completing the prosthesis to fit such a cast. One manufacturer has attempted to meet both impression-making and verification-cast objectives by providing metallic impression copings (MICS) with extensions that allow contact between the copings for rigid fixation with acrylic resin before impression making. The purpose of this study was to determine the accuracy of casts produced from the MICS transfer process compared with casts produced from sectioned frameworks, where both techniques used a low-polymerization-shrinkage acrylic resin polymer to rigidly join the sections. Materials and Methods Using stainless steel measurement spheres as a reference point on each implant analog, the distances between analogs on the experimental casts were compared with the distances measured on the master cast. Seven casts were produced for each group and measured with a machinist's microscope at a 4-μm level of precision. Results The results revealed that the MICS transfer exhibited a mean error of 41 μm, which was significantly less than the verification-cast group mean error of 57 μm (p < .01, Student's t test). Conclusions Given these results, clinicians can consider the rigid transfer technique as provided in the MICS transfer to be more accurate than the verification technique as outlined in this study.     

Dental Caries in Homeless Adults in Boston

Objectives : Information about the oral health status of the homeless is limited. The purpose of this study is to characterize the dental caries status among users of a dental treatment and referral program at homeless shelters in Boston, MA. Methods : Persons attending the program during a one-year period were assessed for evidence of dental caries experience by a single examiner. DMFT counts were abstracted from patient records. Results : The population examined (n=73) was 66 percent male with a mean age of 36 years. The racial composition was 51 percent African-American, 34 percent Caucasian, and 14 percent Hispanic. The 70 dentate people examined had a mean DFT of 11.1 (SD=6.1). The mean percent of DFT that was DT per person was 55.7 percent. Untreated caries was detected in 91.4 percent of those examined. Conclusions : These findings show evidence of previous dental services utilization by these homeless individuals, but demonstrate a high need for preventive and restorative dental therapy.     

Utility of the Dental Aesthetic Index in Industrialized and Developing Countries

To be truly useful, an index must be applicable universally without modification. The data presented in this article support the use of the standard DAI without modification to assess need for orthodontic treatment in both developing and industrialized countries. When students from Thailand, Australia, the German Democratic Republic, and Native Americans residing on Indian reservations rated the same 25 occlusal stimuli (photographs of dental configurations) for dental aesthetics, their ratings of these stimuli when arranged in rank order were highly correlated with those of US students. These 25 occlusal stimuli were a subset of the original 200 occlusal stimuli used in deriving the standard DAI regression equation. This article presents data indicating that when a Native American DAI was derived based on Native American ratings of the same 200 occlusal stimuli used in deriving the standard DAI, the Native American DAI and the standard DAI had the same ten components (orthodontic measurements) and strikingly similar regression coefficients (weights). Further analysis indicated that the two equations were sufficiently similar to justify using the standard DAI to obtain DAI scores on Native Americans and to estimate the relative social acceptability of their dental aesthetics. If ratings for dental aesthetics for the full set of 200 stimuli were available for each of the countries where only 25 were rated, we expect that, as in the case of Native Americans, a country-specific DAI, if computed, would be sufficiently similar to the standard DAI that no modification would be needed to allow use of the standard DAI in that country.(ABSTRACT TRUNCATED AT 250 WORDS)     

Simulation of condylar growth in the cat with pulsating electromagnetic currents

Orthodontists have been, and are, interested in influencing facial growth, specifically, mandibular growth. The purpose of this investigation is to enhance condylar growth by means of electric stimulation. Eight growing cats were bilaterally condylotomized and unilaterally at random received electric stimulation. Before the condylotomy bonemarkers were implanted in the zygomatic process and above the condylotomy site. The condylotomy effectively separated the head of the condyle from the body of the mandible, thus unloading the head. After 5 weeks, implant separation indicated increased condylar growth on the treated side of all eight cats. Histologically, the treated condyles of six cats were different from the controls in that the hypertrophic zone was irregular and vascularization increased. The treated condyle showed significantly more bonemarker separation than the control condyle. On average, the treated condyle showed 1.24 mm more separation than the control (p = 0.001 by the paired sample t test). (AM J ORTHOD DENTOFAC ORTHOP 1995;108:599-606.)     

Long-term outcomes for remedial students

A recent survey of dental schools concluded that current efforts toward remediation are inadequate. A remedial waxing course providing recognition training before production attempts, emphasis on formative self- and peer-evaluation of projects, and application of a highly structured format for ensuring relevant practice had been developed and favorably evaluated previously. The current report follows the progress of two differently trained remedial groups and the remainder of the class in two courses following remediation. On the five subsequent practical examinations analyzed, the experimental group continued to perform at the class mean. On one practical examination, the experimental group significantly outperformed the traditional group (p less than 0.02). For three of the five examinations, the traditional group was significantly outperformed by the class. One of the six students in the experimental group required additional remediation. Of the seven in the traditionally remediated group, one left school and four required additional remediation. An apparent changing remediation pattern in the preclinical training period is described and possible reasons for the change are explored.     

Short-Term Results of IPS-Empress Inlays and Onlays

Purpose A leucite-reinforced, glass-ceramic material was recently introduced for clinical use. In this clinical trial, IPS-Empress inlays and onlays were evaluated using the modified United States Public Health Service (USPHS) criteria. Materials and Methods The teeth of 36 patients were restored with 105 posterior inlays and 25 onlays, fabricated by an indirect technique. After etching the restorations with hydrofluoric acid, they were silanized and luted using composite cements. The restorations were evaluated visually, clinically with a mirror and probe, and by bitewing radiographs and clinical photographs, using modified USPHS criteria. Restorations having neither charlie nor delta criteria were defined as successful, and their survival rate was calculated according to Kaplan-Meier analysis. Results The mean observation period for the 130 restorations was 23.4 ± 6.1 months. After 2 years, 127 restorations were successful with an estimated survival rate of 97.5%. Three restorations failed because of fractures. The esthetic results were excellent. Conclusions The initial clinical results of this esthetic restorative material are encouraging. However, because of fatigue phenomena for all ceramic materials, a longer observation period is needed to provide a definitive prognosis of the long-term clinical behavior.