A successful implant-supported fixed prosthesis in a patient with osteopetrosis: A clinical report.

Osteopetrosis (marble bone disease) is a family of rare genetic disorders characterized by impaired osteoclast function leading to hyperdense, hypovascular, brittle bone. Typical imaging shows increased bone mass and thickened cortical and trabecular bone. Bones are more prone to fracture and osteomyelitis may develop. When considering dental implant placement in a patient with osteopetrosis, the potential for bony fracture and/or osteomyelitis should be considered along with the decreased likelihood of successful osseointegration because of hypovascularity. This clinical report describes an unusual imaging presentation and successful osseointegration of multiple dental implants supporting an implant-supported fixed mandibular prosthesis with long-term survival.

Effect of simulated intraoral variables on the accuracy of a photogrammetric imaging technique for complete-arch implant prostheses.

STATEMENT OF PROBLEM: Conventional impression techniques to obtain a definitive cast for a complete-arch implant-supported prosthesis are technique-sensitive and time-consuming. Direct optical recording with a camera could offer an alternative to conventional impression making. PURPOSE: The purpose of this in vitro study was to test a novel intraoral image capture protocol to obtain 3-dimensional (3D) implant spatial measurement data under simulated oral conditions of vertical opening and lip retraction. MATERIAL AND METHODS: A mannequin was assembled simulating the intraoral conditions of a patient having an edentulous mandible with 5 interforaminal implants. Simulated mouth openings with 2 interincisal openings (35 mm and 55 mm) and 3 lip retractions (55 mm, 75 mm, and 85 mm) were evaluated to record the implant positions. The 3D spatial orientations of implant replicas embedded in the reference model were measured using a coordinate measuring machine (CMM) (control). Five definitive casts were made with a splinted conventional impression technique of the reference model. The positions of the implant replicas for each of the 5 casts were measured with a Nobel Procera Scanner (conventional digital method). For the prototype, optical targets were secured to the implant replicas, and 3 sets of 12 images each were recorded for the photogrammetric process of 6 groups of retractions and openings using a digital camera and a standardized image capture protocol. Dimensional data were imported into photogrammetry software (photogrammetry method). The calculated and/or measured precision and accuracy of the implant positions in 3D space for the 6 groups were compared with 1-way ANOVA with an F-test (α=.05). RESULTS: The precision (standard error [SE] of measurement) for CMM was 3.9 µm (95% confidence interval [CI] 2.7 to 7.1 µm). For the conventional impression method, the SE of measurement was 17.2 µm (95% CI 10.3 to 49.4 µm). For photogrammetry, a grand mean was calculated for groups MinR-AvgO, MinR-MaxO, AvgR-AvgO, and MaxR-AvgO obtaining a value of 26.8 µm (95% CI 18.1 to 51.4 µm). The overall linear measurement error for accurately locating the top center points (TCP) followed a similar pattern as for precision. CMM (coordinate measurement machine) measurement represents the nonclinical gold standard, with an average error TCP distance of 4.6 µm (95% CI 3.5 to 6 µm). All photogrammetry groups presented an accuracy that ranged from 63 µm (SD 17.6) to 47 µm (SD 9.2). The grand mean of accuracy was calculated as 55.2 µm (95% CI 8.8 to 130.8 µm). CONCLUSIONS: The CMM group (control) demonstrated the highest levels of accuracy and precision. Most of the groups with the photogrammetric method were statistically similar to the conventional group except for groups AvgR-MaxO and MaxR-MaxO, which represented maximum opening with average retraction and maximum opening with maximum retraction.

An in vitro comparison of photogrammetric and conventional complete-arch implant impression techniques.

STATEMENT OF PROBLEM: Conventional impression techniques for recording the location and orientation of implant-supported, complete-arch prostheses are time consuming and prone to error. The direct optical recording of the location and orientation of implants, without the need for intermediate transfer steps, could reduce or eliminate those disadvantages. PURPOSE: The objective of this study was to assess the feasibility of using a photogrammetric technique to record the location and orientation of multiple implants and to compare the results with those of a conventional complete-arch impression technique. MATERIAL AND METHODS: A stone cast of an edentulous mandibular arch containing 5 implant analogs was fabricated to create a master model. The 3-dimensional (3D) spatial orientations of implant analogs on the master model were measured with a coordinate measuring machine (CMM) (control). Five definitive casts were made from the master model with a splinted impression technique. The positions of the implant analogs on the 5 casts were measured with a NobelProcera scanner (conventional method). Prototype optical targets were attached to the master model implant analogs, and 5 sets of images were recorded with a digital camera and a standardized image capture protocol. Dimensional data were imported into commercially available photogrammetry software (photogrammetric method). The precision and accuracy of the 2 methods were compared with a 2-sample t test (α=.05) and a 95% confidence interval. RESULTS: The location precision (standard error of measurement) for CMM was 3.9 µm (95% CI 2.7 to 7.1), for photogrammetry, 5.6 µm (95% CI 3.4 to 16.1), and for the conventional method, 17.2 µm (95% CI 10.3 to 49.4). The average measurement error was 26.2 µm (95% CI 15.9 to 36.6) for the conventional method and 28.8 µm (95% CI 24.8 to 32.9) for the photogrammetric method. The overall measurement accuracy was not significantly different when comparing the conventional to the photogrammetric method (mean difference = -2.6 µm, 95% CI -12.8 to 7.6). CONCLUSIONS: The precision of the photogrammetric method was similar to CMM, but lower for the conventional method as compared to CMM and the photogrammetric method. However, the overall measurement accuracy of the photogrammetric and conventional methods was similar.

Selection patterns of dietary foods in edentulous participants rehabilitated with maxillary complete dentures opposed by mandibular implant-supported prostheses: a multicenter longitudinal assessment.

STATEMENT OF PROBLEM: Documentation of long-term changes in food intake is lacking for those treated with a maxillary complete denture opposed by a mandibular, screw-retained, implant-supported fixed prosthesis. PURPOSE: The purpose of this study was to evaluate the selection patterns of dietary foods over 5 years for edentulous participants treated in a multicenter prospective clinical trial that compared cast alloy versus laser-welded titanium frameworks of an implant-supported prostheses opposed by maxillary complete dentures to rehabilitate edentulous participants. MATERIAL AND METHODS: The study assessed data from a multicenter prospective clinical trial that followed edentulous participants from an initial baseline of wearing existing complete dentures to implant placement, restoration with a mandibular implant-supported prosthesis opposed by a maxillary complete denture, to follow-up assessment of these treatments over 5 years. The 32 participants in the cohort were treated at 5 of 9 participating centers. The data collected included 2 dietary forms, a standardized 4-day food diary form, and a dietary habits questionnaire. Each participant completed forms before entering into treatment (control) and at the 1- and 5-year follow-up assessment after being treated with a maxillary complete denture opposing a mandibular complete-arch fixed implant-supported prosthesis. Descriptive statistics were calculated for each measure at each assessment point. Regression analysis and the Sign test were used to calculate change in the participants' nutritional status (α=.05). RESULTS: Among the findings, it was noted that difficulty in masticating hard, raw, and fibrous foods decreased and intake of vegetable portions increased significantly from 2.5 to 3.3 servings. Participant comfort in eating in public places and their enjoyment of eating were significantly improved from 50% of participants being uncomfortable with their prior complete denture treatment to only 4% after 5 years. CONCLUSIONS: Within the limitations of this study, it was concluded that vegetable intake and ability to masticate raw, hard, and fibrous food for these participants improved when they received a mandibular implant-supported prosthesis opposed by a maxillary complete denture. According to the analysis and findings, the overall eating experience was more pleasurable, and eating in public was more comfortable after replacement of complete dentures with a mandibular implant-supported prosthesis.

In vitro assessment of three types of zirconia implant abutments under static load.

STATEMENT OF PROBLEM: Although various zirconia abutments have been introduced, insufficient data exist regarding the maximum load capacity of internal tri-channel connection zirconia implant abutments with various implant-abutment interfaces. PURPOSE: The purpose of this in vitro study was to compare the maximum load capacity of 3 different types of internal tri-channel connection zirconia abutments and to assess their mode of failure. MATERIAL AND METHODS: The study investigated 3 groups (n=20) of zirconia implant abutments with different implant-abutment interfaces. Group AllZr consisted entirely of zirconia (Aadva CAD/CAM Zirconia Abutment), group FrZr of a titanium insert friction-fitted to the zirconia abutment component (NobelProcera Abutment Zirconia), and group BondZr of a titanium insert bonded to the zirconia abutment component (Lava Zirconia abutment). All the abutments were thermal cycled for 20 000 cycles between 5°C and 55°C. Sixty test implants made of titanium (Dummy NobelReplace) were embedded in autopolymerizing acrylic resin, and 60 zirconia copings (Lava Zirconia) with a uniform thickness of 2.0 mm were fabricated and bonded to the abutments. A universal testing machine was used to statically load all the specimens at a crosshead speed of 1 mm/min. The maximum load was recorded and used as the failure load. The fractured specimens were collected and representative specimens were studied with a stereomicroscope and scanning electron microscope (SEM). One-way ANOVA and post hoc comparisons with the Tukey HSD tests were used for statistical analysis (α=.05). RESULTS: The mean (SD) maximum load capacity was 484.6 (56.6) N for NobelProcera, 503.9 (46.3) N for Aadva, and 729.2 (35.9) N for Lava abutments. The maximum load capacity of Lava abutments was significantly higher than that of Aadva or NobelProcera (P< 05). No significant difference between Aadva and NobelProcera abutments was noted. The mode of failure among the Aadva, NobelProcera, and Lava abutments was different. CONCLUSIONS: With standard diameter internal tri-channel connection implants, the maximum load capacity of the Lava abutment was significantly higher than that of the Aadva or NobelProcera abutment. No significant difference in maximum load capacity was noted between Aadva and NobelProcera abutments. However, the fracture behavior of all 3 abutments was different.

Complete arch implant impression technique.

When making a definitive impression for an arch containing multiple implants, there are many reported techniques for splinting impression copings. This article introduces a splint technique that uses the shim method, which has been demonstrated to reduce laboratory and patient chair time, the number of impression copings and laboratory analogs needed, and the ultimate cost.

Freedom of rotation of selected overdenture attachments: an in vitro study.

STATEMENT OF PROBLEM: Attachments for mandibular overdentures may not allow for adequate freedom of rotation. PURPOSE: The purpose of this study was to subject 3 commonly used stud types of resilient attachments to rotation and to measure and compare the degree of rotation that occurs before the attachments bind. MATERIAL AND METHODS: Three stud attachments (ERA, Locator Extended Range, O-Ring System) with their corresponding metal housings were evaluated, first for a single implant system and secondly for a 2-attachment parallel implant system for the mandibular arch. Both the manufacturers' most and least retentive components were tested in each system. In the Locator system, the medium retention (3 lbs) for the standard is the most retentive of the extended range. A total of 60 test specimens, 5 per group, were fabricated. The attachments were connected to a 115-mm rod and attached to a testing device composed of a base, implant analogs, and a vertical plate holding graph paper. A free-sliding plastic block, which supported the metal rod parallel to the base, was removed to release the rod. The distance the rod fell was photographed and input into a computer with software designed to measure linear movement. Three-way ANOVA with heteroscedasticity consistent standard errors was used for data analyses (α=.05). RESULTS: Significant differences found among the most retentive components showed that the Locator had a greater freedom of rotation than the ERA (P=.001). The most retentive components in all systems showed that 1 attachment had a greater freedom of rotation than 2 (P=.005). When testing the least retentive components, all systems were significantly different (P<.003), with the freedom of rotation ranking being O-Ring System > Locator Extended Range > ERA. For all 3 systems, the least retentive components showed the most freedom (P≤.008). CONCLUSIONS: The least retentive components offer greater rotation than the most retentive components for all attachment systems tested and for both single and double attachments. Using the most retentive components, the Locator Extended Range attachment allows greater rotation than does the ERA for both single and double attachments. Using the least retentive components, the ORS attachment allows the most rotation and ERA the least for both single and double attachments. Using the most retentive components, one attachment allows greater rotation than does 2 attachments for the attachment systems evaluated.

The use of computer-aided manufacturing during the treatment of the edentulous mandible in an oral radiation therapy patient: clinical report.

This clinical report describes the treatment of an edentulous patient with previous radiation therapy to the base of the tongue. A computer-aided manufactured titanium framework was used to fabricate the implant-supported fixed complete denture and meet the functional and psychosocial needs of the patient.

Shear bond strength of denture teeth to heat- and light-polymerized denture base resin.

PURPOSE: To evaluate the shear bond strengths of highly cross-linked denture teeth bonded to heat-polymerized poly(methyl methacrylate) (PMMA) or a light-polymerized urethane dimethacrylate (UDMA) denture base resin with or without a diatoric and with or without an acrylate bonding agent. MATERIALS AND METHODS: The denture base resins tested were Lucitone 199 (heat-polymerized PMMA) and Eclipse (light-polymerized UDMA). One hundred sixty mandibular central incisor denture teeth were divided into four groups (n = 40): group 1: ground surface as control; group 2: ground surface with diatoric; group 3: ground surface with bonding agent; group 4: ground surface with bonding agent and diatoric. Half of each group (n = 20) was processed with either heat- or light-polymerized resin. All specimens were treated with thermocycling for 1000 cycles, alternating between 5 and 55 °C with a dwell time of 30 seconds. Half the specimens in each group were treated with cyclic loading at 22 N for 14,400 cycles at 1.5 Hz. All specimens were tested with shear load to failure. Data were analyzed with student's t-test, 2- and 3-way ANOVA, and Dunnett's T3 method (p < 0.05). RESULTS: Statistical analysis demonstrated no significant effect on shear bond strength from cyclic loading. For the Lucitone 199 (L) specimens, mean shear bond strengths and standard deviations were (N) 66.5 ± 28.4, 72.7 ± 31.5, 80.6 ± 17.1, and 76.9 ± 21.9 for groups 1L, 2L, 3L, and 4L, respectively. For the Eclipse (E) specimens, mean shear bond strengths and standard deviations were (N) 3.7 ± 1.2, 7.3 ± 3.3, 90.0 ± 20.7, and 94.2 ± 17.8 for groups 1E, 2E, 3E, and 4E, respectively. No statistically significant differences in shear bond strengths were noted for the Lucitone 199 groups (p = 0.11). Eclipse shear bond strengths were significantly higher in groups 3E and 4E than in groups 1E and 2E (p ≤ 0.05). In a 3-way ANOVA for groups 3 and 4, the shear bond strengths for the Eclipse specimens were significantly higher than the Lucitone 199 specimens (p = 0.01). CONCLUSIONS: When evaluating the shear bond strength of IPN denture teeth to denture base resins, specimens using an acrylate bonding agent with the Eclipse (light-polymerized) resin yielded significantly higher shear bond strengths than all of the Lucitone 199 groups and the Eclipse resin groups without a bonding agent.

Outcomes assessment of patients treated with osseointegrated dental implants at the University of Washington Graduate Prosthodontic Program, 1988 to 2000.

PURPOSE: The purpose of this retrospective study was to review and assess the outcomes of subjects treated with dental implants at the University of Washington Graduate Prosthodontic Program from 1988 to 2000. MATERIALS AND METHODS: A retrospective review and an outcomes assessment were conducted of patients treated with osseointegrated implants between 1988 and 2000 at the University of Washington Graduate Prosthodontic Program. Patients were treated by graduate students. All included patients had a prosthesis that had been in service for at least 5 years. Implants and prostheses were assessed by chart review, phone survey, and clinical review. Clinical review consisted of mobility testing, soft tissue evaluation, and occlusal evaluation. Specific success criteria were used and life table analyses of implants and prostheses were performed. RESULTS: Of a total of 114 patients treated, 69 subjects (60.5% of those treated) participated in the assessment; 103 prostheses supported by 273 implants were reviewed clinically. The estimated cumulative survival rate was 96.3% for all implants and 85.4% for all prostheses. CONCLUSIONS: A retrospective review of 69 subjects who were treated in the University of Washington Graduate Prosthodontic Program between the years 1988 and 2000 showed an implant survival rate of 96.3% and a prosthesis survival rate of 85.4%. Prostheses showed higher failure rates than implants.

A comparison of two solder registration materials: a three-dimensional analysis.

STATEMENT OF PROBLEM: Use of a segmental indexing/soldering approach for assembly of complete arch implant frameworks has been advocated by some clinicians to achieve a passively fitting framework. To the authors' knowledge, a mathematical assessment using a 3-dimensional (3-D) distortion analysis has not been performed comparing segmental framework assembly to reassembly of 1-piece complete arch frameworks that required sectioning, indexing, and soldering. PURPOSE: The present study compared the use of 2 indexing materials, autopolymerizing acrylic resin and light-polymerized composite resin, for use in solder registration of complete-arch implant frameworks using 3 framework/indexing material combinations: gold/light-polymerized composite resin, silver palladium/autopolymerizing acrylic resin, and silver palladium/light-polymerized composite resin. MATERIAL AND METHODS: Five frameworks for each alloy/index combination were fabricated, for a total of 15 frameworks. Each framework was fitted to 5 implant abutments. Measurements were made of the initial gold cylinder/abutment positions for each of the 5 sites for the 15 frameworks. The 3-D spatial orientation of each gold cylinder/abutment was calculated prior to the gold cylinders being incorporated into the framework casting and served as the control against which all measurements were compared. After the indexing/soldering procedures, the 3-D spatial orientations of the cylinders were measured, first as 2- and 3-unit solder assembled framework segments and, finally, for complete-arch frameworks. These measurements were recorded in micrometers for linear distortions and degrees for angular distortions using a coordinate measurement machine (CMM). These data were compared and statistically assessed using a 1-way analysis of variance (ANOVA). A Student-Newman-Keuls test was used to determine significance between cylinders within each indexing combination. A repeated-measures ANOVA and a Student-Newman-Keuls test were used to determine significance between alloy/index group and cylinders for each of the measurement variables with statistical significance at alpha=.05 for all statistical analyses. RESULTS: Mean differences and SDs of total linear change for all groups found dR (total linear change) to be 33.56 +/- 27.70 mum for gold/light-polymerized composite resin, 34.87 +/- 27.99 mum for silver palladium/autopolymerizing acrylic resin, and 31.56 +/- 24.37 mum for silver palladium/light-polymerized composite resin. Total angular change, dtheta(R), was calculated to be 0.47 +/- 0.13 degrees for gold/light-polymerized composite resin, 0.46 +/- 0.17 degrees for silver palladium/autopolymerizing acrylic resin, and 0.52 +/- 0.15 degrees for silver palladium/light-polymerizing composite resin. CONCLUSIONS: No significant differences were found between alloy/index combinations, except for the measured variable dtheta(y), angular change about the Y axis.

Osseointegrated craniofacial implants in the rehabilitation of orbital defects: an update of a retrospective experience in the United States.

STATEMENT OF PROBLEM: Since their introduction, craniofacial implants have been used in prosthetic rehabilitation of facial defects. The literature, however, indicates marked variability in outcomes using implants for the retention of orbital prostheses. PURPOSE: A multicenter report updating the experience in the United States with the use of craniofacial implants for prosthetic rehabilitation of orbital defects is presented. MATERIAL AND METHODS: Surveys were sent to clinicians at 25 centers where maxillofacial prosthetic treatment is provided to obtain retrospective data regarding patients who completed implant-retained orbital prosthetic rehabilitation. Data on implant placement location, radiation treatment history, and use of hyperbaric oxygen therapy were collected and assessed in relationship to implant survival over time. The Kaplan-Meier life table and Wilcoxon analyses (alpha = .05) were used to assess the significance of the findings. RESULTS: Ten centers responded, providing data suitable for statistical analysis on 153 implants placed to retain 44 orbital prostheses and followed for a mean period of 52.6 months. Forty-one implant integration failures occurred during this follow-up period, resulting in an overall integration survival rate of 73.2%. No significant relationship was found between radiation treatment history, hyperbaric oxygen therapy history, or implant placement location and implant survival. Individual responses revealed large variability between reporting centers in treatment outcomes. CONCLUSION: Craniofacial implants may offer marked benefits in the prosthetic rehabilitation of orbital defects when compared to conventional adhesive retention designs. However, questions remain regarding long-term predictability and the impact specific factors may have on treatment outcomes. Insufficient data is currently available from which to draw statistically meaningful conclusions. The establishment of a national database designed to acquire adequate data to assess treatment outcomes is recommended.

A light-polymerized resin support tray as an aid for recording centric relation.

For patients who require complex fixed prosthodontic oral rehabilitation, recording an accurate centric relation is often a difficult procedure. A minimal number of abutment teeth or implants may not offer adequate support for the occlusal registration material. In the described technique, Triad tray material is used as an occlusal registration supporting tray. This procedure is accurate and convenient for the restorative dentist.