Search

Purpose: This study evaluated the recall attendance and maintenance for a patient population after prosthodontic treatment in undergraduate student courses. Materials and Methods: Four hundred ninety-three patients who received fixed restorations (FRs; crowns or fixed partial dentures) or removable partial dentures (RPDs; conical crown-retained or precision attachment-retained dental prostheses) were included in a recall program. The number of patients attending regularly scheduled follow-up visits every 6 months was recorded. On the basis of the complexity of the performed treatment, all follow-up interventions were assigned to the categories minimal, moderate, or extensive. Results: After 60 months, a cumulative follow-up attendance rate between 63% (RPD) and 74% (FR) was evident and not gender related. Altogether, 399 patients (193 FR, 206 RPD) regularly attended the follow-up visits. Between 61.9% (RPD) and 93.8% (FR) of these patients did not need any extensive treatment; however, only 19.2% (RPD) to 85.6% (FR) did not need any moderate or extensive treatment between follow-up visits. Conclusions: Patients treated with FRs showed a higher recall attendance than patients treated with RPDs. Further, patients with RPDs needed more extensive and moderate treatments than patients with FRs. This difference should be taken into consideration during prosthetic planning and patient consultation. [ABSTRACT FROM AUTHOR]

PURPOSE: The purpose of this study was to evaluate and to compare the bone-cutting performance and intraosseous temperature development of three modern ultrasonic devices for bone surgery (UDBS). MATERIALS AND METHODS: The following UDBS and associated cutting tips (straight bone saws) were used in this study: (1) Piezosurgery II professional, tip OT 7 (Mectron); (2) Piezotome, tip BS 1 (Acteon); and (3) SurgySonic, tip ES007 (American Dental Systems/Gunther Jerney). In the experimental setup UDBS, handpieces were immobilized, and bone specimens from the middiaphysis of a bovine femur were moved in a longitudinal direction under the cutting tip to a standardized depth of 3.0 mm. Intraosseous temperature development was measured using a glass-fiber isolated thermocouple. The cutting performance was defined by the time required to reach the cutting depth of 3.0 mm. Statistical analysis was performed using the Wilcoxon rank sum test. RESULTS: The median increase (25th through 75th percentiles) of the local intraosseous temperature was 3.0 degrees C (2.2 degrees C to 4.2 degrees C) for the SurgySonic, 2.2 degrees C (1.8 degrees C to 3.2 degrees C) for the Piezosurgery II, and 1.1 degrees C (0.7 degrees C to 1.6 degrees C) for the Piezotome. The median cutting performance was 0.31 mm/s (0.11 to 0.46 mm/s) for the Piezotome, 0.25 mm/s (0.23 to 0.27 mm/s) for the Piezosurgery II, and 0.04 mm/s (0.03 to 0.05 mm/s) for the SurgySonic. CONCLUSIONS: Among the three tested UDBS, the Piezotome and the Piezosurgery II showed a significantly higher cutting performance than the SurgySonic. The Piezotome produced the smallest increase in intraosseous temperature. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate whether there is a need to develop a new questionnaire measuring dental appearance or if this is already covered by the Oral Health Impact Profile (OHIP-49). Materials and Methods: Based on internationally accepted guidelines about dental esthetics, a questionnaire was developed to measure dental appearance (QDA). Eleven items defined a QDA sum score (0 = absolutely satisfied, 44 = absolutely dissatisfied). Furthermore, oral health-related quality of life was evaluated using the German version of the OHIP-49 and the OHIP- esthetic. Thirty patients (14 women, 16 men; mean age 59 ± 10 years) were included in the study. All patients received a complete oral rehabilitation including the anterior teeth of the maxilla. Ouestionnaires were completed before and after treatment. Results: The median values were 16 and 1.5 for the QDA sum score, 46 and 16 for the OHIP sum score, and 14.5 and 2 for the OHIP-esthetic before and after rehabilitation, respectively. The improvement after treatment was significant for all questionnaires (P< or equal to 0001) Between the QDA sum score and the OHIP sum score or any of the OHIP subscales (the only exception being 'psychological discomfort'), no significant correlation could be found (P > .05). Between the QDA sum score and the OHIPesthetic, a significant correlation could be found before treatment (r = 0.505, P= .004) but not after treatment (P > .05). Conclusions: If the OHIP-49 is used in clinical studies and a profound evaluation of dental appearance is desired , it is reasonable to use an additional esthetic modulus. [ABSTRACT FROM AUTHOR]

Implant-retained overdentures are a reliable treatment option for edentulous patients, especially when only few implants can be placed. Internationally, 2 implants are considered adequate to retain an overdenture in the edentulous mandible. However, for many patients, 2 implants can be cost-prohibitive. By means of 2 clinical cases, it is shown that the insertion of a single implant in the middle of the mandible might stabilize the prosthesis and improve the oral health quality of life and the chewing function. A ball attachment with a screw-activated matrix was used to retain the overdenture. Early clinical results are promising. However, before this method can be recommended for general clinical application, long-term clinical results are needed. [ABSTRACT FROM AUTHOR]

Subgingival crown-root fractures often present clinical problems when a restorative coverage of the fracture line conflicts with the biological width. Accepted treatment options include the extrusion of the remaining root with a conventional orthodontic appliance, surgical crown lengthening of the root, or root extraction with prosthetic tooth replacement. After considering esthetics and function, orthodontic extrusion with magnets might also be a viable alternative. In this report, a simplified method of orthodontic extrusion with magnets is presented. [ABSTRACT FROM AUTHOR]

PURPOSE: Various ceramic implant systems made of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) have become commercially available in recent years. A systematic search of the literature was performed to assess the clinical success of dental Y-TZP implants and whether the osseointegration of Y-TZP is comparable to that of titanium, the standard implant material. MATERIALS AND METHODS: The internet database MEDPILOT was searched cumulatively for the keywords zircon* and dent* and implant as well as for zircon* and osseointegration. The last search was conducted on January 31st, 2007. Subsequently, the reference lists of the relevant publications were searched. Furthermore, a letter was sent to the 5 identified manufacturers of zirconia dental implants to ask for peer-reviewed publications. RESULTS: Ninety-six articles were found by the search strategy. No controlled clinical studies in humans regarding clinical outcomes or osseointegration could be identified. Clinical data were restricted to case studies and case series. Only 7 animal studies fulfilled the inclusion criteria. Osseointegration was evaluated at 4 weeks to 24 months after placement in different animal models and sites and under different loading conditions. The mean bone-implant contact percentage was above 60% in almost all experimental groups. In studies that used titanium implants as a control, Y-TZP implants were comparable to or even better than titanium implants. Surface modifications may further improve initial bone healing and resistance to removal torque. CONCLUSIONS: Y-TZP implants may have the potential to become an alternative to titanium implants but cannot currently be recommended for routine clinical use, as no long-term clinical data are available. [ABSTRACT FROM AUTHOR]

PURPOSE: This study aimed to correlate the general well-being of patients and their judgment about their dental appearance. MATERIALS AND METHODS: Based on internationally accepted guidelines regarding dental esthetics, a questionnaire was developed to measure subjective assessments of dental appearance. Fourteen items defined an esthetic sum score (0 = satisfied; 56 = dissatisfied). Further, general well-being was evaluated with a long-established and highly reliable test. Eighty participants were included (47 women, 33 men). Participants were.drawn from 4 different groups (n = 20): natural dentition (group N), fixed partial dentures (group F), removable partial dentures (group R), and patients who had an esthetic problem with their teeth (group P). RESULTS: Seventy-five participants showed a normal well-being. Five participants showed a depressive state and formed a new group (group D). The medians of the sum scores (25th, 75th percentile) were: group N: 12 (10, 14); group F: 14 (8, 29); group R: 14 (9, 27); group P: 23 (18, 35); group D: 30 (26, 35). Significant differences were found between groups N and P, as well as between group D and groups N, F, and R. CONCLUSION: Because of the significant difference between groups N and P, basis validation of the sum score was achieved. Further, self-assessments of dental appearance appeared to be more negative for participants with a depressive state compared with the other groups. In clinical studies, selection bias can be prevented by using a test that measures well-being to verify if a study sample includes a normal number of depressive subjects and therefore represents the general population. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this in vitro study was to evaluate the influence of cement type and application technique on seating discrepancies and retention forces of noble alloy castings cemented on titanium abutments. Materials and Methods: Eugenol-free zinc oxide (Freegenol), zinc phosphate (Harvard), glass ionomer (KetacCem), polycarboxylate (Durelon), and self-adhesive resin (RelyX Unicem) cements were used. The inner surfaces of the castings were either completely coated or half-coated with cement. Abutments were used as delivered with a machined surface for the first part of the study. Groups of 8 castings were cemented in both ways. For the second part of the study, the abutments were air-abraded (aluminum oxide, 50 mirom particle size), and groups of 8 completely coated castings were cemented with all cements. Marginal discrepancies were measured before and immediately after cementation. Tensile tests were conducted to measure the retention forces. Statistical analysis was performed with pair-wise comparison using the Wilcoxon rank sum test modified by Bonferroni-Holm. Results: Change in seating discrepancies did not differ significantly among the different application techniques. The median retention forces for completely-coated castings were 177 N for eugenol-free zinc oxide, 346 N for zinc phosphate, 469 N for glass ionomer, 813 N for polycarboxylate, and 653 N for self-adhesive resin. With respect to retention force, 3 significantly different groups (P

In a previous clinical study, all-ceramic resin-bonded 3-unit inlay-retained fixed partial dentures (IRFPDs) had a significantly worse outcome in the posterior region than did crown-retained 3-unit FPDs made from the same material. Debonding or fractures were causes of failure. To improve the clinical outcome of IRFPDs, a new framework design was developed: (1) The inlay retainers were made out of CAD/CAM-manufactured zirconia ceramic to improve fracture resistance, and additional veneering of the inlays was omitted. (2) The inlay retainers were completed with a shallow occlusal inlay (1-mm minimum thickness) and an oral retainer wing (0.6-mm minimum thickness). The wings were designed to reduce stress on the inlay retainer caused by torsion forces when the FPD is loaded nonaxially and to increase the enamel adhesive surface area. The pontic was circumferentially veneered with feldspathic porcelain. The clinical and laboratory procedures of this new treatment modality are described, and 2 exemplary clinical cases are presented. This new preparation and framework design might improve the clinical outcome of all-ceramic resin-bonded IRFPDs. However, adequate evidence of long-term safety and efficacy is required before this new design can be recommended for general clinical practice. [ABSTRACT FROM AUTHOR]

PURPOSE: Microbial leakage and colonization between implants and their abutments may cause inflammatory reactions in the peri-implant tissues. This study evaluated microbial leakage at the implant-abutment interface with a new in vitro model. MATERIALS AND METHODS: Bacterial leakage was tested during dynamic loading in a 2-axis chewing simulator. The authors theorized that dynamic loading would decrease the stability of the implant-abutment connections and thereby lead to bacterial penetration along the gap. Five different implant systems with 8 standard implant-abutment combinations for single molar crowns were tested. The internal aspects of the implants were inoculated with a bacterial suspension and connected to the superstructure with the recommended torque. The specimens were immersed in a nutrient solution and loaded with 1,200,000 cycles of 120 N in the chewing simulator. RESULTS: Statistically significant differences (P < or = .05) between implant systems with respect to number of chewing cycles until bacterial penetration were found. DISCUSSION: The degree of penetration in a specific implant system presumably is a multifactorial condition dependent on the precision of fit between the implant and the abutment, the degree of micromovement between the components, and the torque forces used to connect them. CONCLUSION: It was concluded that the newly developed test model is a sensitive tool for the detection of differences between current implant systems with respect to their ability to prevent bacterial penetration at the implant-abutment interface under dynamic loading conditions. [ABSTRACT FROM AUTHOR]

The aim of this prospective study was to evaluate the clinical outcomes of three and four-unit posterior fixed dental prostheses (FDPs) made of In-Ceram Zirconia. Twenty FDPs were inserted in 15 patients. Over a mean observation period of 74.6 months, the survival rate was 85%. Sixty-five percent of cases did not allow for connector dimensions that met the manufacturer's recommendations without the use of surgical procedures (eg, crown lengthening). Posterior all-ceramic FDPs made of In-Ceram Zirconia appear to be a viable prosthetic treatment option to replace a missing tooth. [ABSTRACT FROM AUTHOR]

This prospective study evaluated the clinical outcome of three-unit posterior fixed dental prostheses (FDPs) made of In-Ceram Zirconia. All 65 FDPs were inserted at the Department of Prosthodontics, School of Dentistry, Kiel, Germany, and cemented with glass-ionomer cement. Follow-ups were performed annually. During a mean observation time of 54.4 months, two FDPs failed (one technical and one biologic failure). Two FDPs debonded and the veneering ceramic fractured in four cases. Three abutment teeth needed endodontic treatment and two additional abutment teeth exhibited secondary caries. Results suggest that posterior three-unit all-ceramic FDPs made from In-Ceram Zirconia may be a viable prosthetic treatment option with an outcome comparable to metal-ceramic FDPs. [ABSTRACT FROM AUTHOR]

This in vitro study aimed to evaluate marginal and internal fit of single crowns produced from high-frequency, ultrasound-based digital impressions of teeth prepared with finish lines covered by porcine gingiva in comparison with those obtained using optical scanners with uncovered finish lines. A total of 10 human teeth were prepared, and 40 zirconia crowns were fabricated from stereolithography (STL) data sets obtained from four dental scanners (n = 10 each): extraoral CS2 (Straumann), intraoral Lava COS (3M), intraoral Trios (3Shape), and extraoral ultrasound scanner. The accuracy of the crowns was compared by evaluating marginal and internal fit by means of the replica technique with measurements in four areas (P1: occlusal surface; P2: transition between occlusal and axial surfaces; P3: middle of axial wall; and P4: marginal gap). Restoration margins were classified according to their mismatch as regular, underextended, or overextended. Kruskal-Wallis one-way analysis of variance and Mann-Whitney U test were used to evaluate the differences between groups at P < .05. The median value of marginal gap (P4) for ultrasound (113.87 µm) differed statistically from that of CS2 (39.74 µm), Lava COS (41.98 µm), and Trios (42.07 µm). There were no statistical differences between ultrasound and Lava COS for internal misfit (P1-P3); however, there were statistical differences when compared with the other two scanners (Trios and CS2) at P1 and P2. The ultrasound scanner was able to make digital impressions of prepared teeth through porcine gingiva (P4), but with less accuracy of fit than conventional optical scanners without coverage of the finish lines. Where no gingiva was available (P1-P3), the ultrasound accuracy of fit was similar to that of at least one optical scanner (Lava COS). [ABSTRACT FROM AUTHOR]