Vertical eruption of anterior maxillary teeth adjacent to single-implant-supported crowns: An assessment after a 3-year follow-up period.

STATEMENT OF PROBLEM: Vertical eruption of teeth adjacent to an implant has been reported clinically and might affect the esthetic outcome over time. The prevalence of the problem is unclear. PURPOSE: The purpose of this prospective clinical trial was to evaluate the vertical eruption of anterior maxillary teeth adjacent to single-implant crowns after a 3-year follow-up period. MATERIAL AND METHODS: Thirty single dental implants were inserted in maxillary anterior sites including the first premolar. The mean age of the participants at implant-supported crown insertion was 48.4 years (range 23 to 79 years). Each implant was restored with a 1-piece screw-retained ceramic single crown. The vertical changes of 60 adjacent anterior maxillary teeth were evaluated from periapical radiographs and casts at baseline, 6, 12, and 36 months. RESULTS: A global ANOVA test showed statistically significant differences for the outcomes of the distance-implant platform and cement-enamel junction (DPC) (P<.001), crown length distal (P=.021) and mesial (P=.035), implant crown length (P=.022), and incisal edge to edge (P<.001). CONCLUSIONS: Continuous vertical tooth eruption next to a single dental implant was observed in adult participants.

Time-efficiency and cost-analysis comparing three digital workflows for treatment with monolithic zirconia implant fixed dental prostheses: A double-blinded RCT.

OBJECTIVES: This double-blinded randomized controlled trial investigated economic performance indicators (EPI) in terms of time-efficiency and production costs of 3-unit monolithic zirconium-dioxide (ZrO2) implant fixed dental prostheses (iFDP) in three different workflows. METHODS: Twenty patients with two Straumann Tissue-Level-Implants received three iFDPs; two were fabricated in proprietary complete digital workflows with intraoral optical scanning and model-free fabrication with company-related CAD/CAM lab-software while one iFDP was manufactured on digitized casts from conventional impressions. The sequence of impression-taking for the three workflows (TRIOS 3/3Shape [Test-1]; Virtuo Vivo/Dental Wings [Test-2]; Impregum/3M Espe [Control]) was randomly allocated. Sixty iFDPs bonded to ti-base abutments were analyzed. Clinical and technical worksteps for Test-1/Test-2/Control were recorded and evaluated for time-efficiency including cost-analysis (CHF=Swiss Francs) using ANOVA-Tests (significance level α=0.05). RESULTS: Mean total work time, as the sum of clinical plus technical steps, was 97.5 min (SD ± 23.6) for Test-1, 193.1 min (SD ± 25.2) for Test-2, and 172.6 min (SD ± 27.4) for Control. Times were significantly different between Test-1/Test-2 (p < 0.00001), Test-1/Control (p < 0.00001), and Test-2/Control (p < 0.03610). Technical costs were 566 CHF (SD ± 49.3) for Test-1, 711 CHF (SD ± 78.8) for Test-2, 812 CHF (SD ± 89.6) for Control, and were also significantly different for all comparisons (p < 0.00001). CONCLUSIONS: Test-1 demonstrated the best performance for time-efficiency, Test-2 revealed the worst result. This indicates that digital workflows are not the same and not necessarily superior to analog workflows of monolithic ZrO2 iFDPs. Complexity decreases by reducing the number of steps following complete digital workflows, resulting in lower production costs compared to the mixed analog-digital workflow with conventional impressions. CLINICAL SIGNIFICANCE: Complete digital workflows comprising intraoral optical scanning without physical models for treatment with monolithic ZrO2 iFDPs is an efficient alternative to mixed analog-digital workflows with conventional impressions and labside digitization of dental casts.

Cost-effectiveness of three different concepts for the rehabilitation of edentulous mandibles: Overdentures with 1 or 2 implant attachments and hybrid prosthesis on four implants.

BACKGROUND: There are scarce data regarding the combined assessment of the costs and effects of implant treatments for edentulous patients when multiple options are available. AIM: This randomised clinical trial aimed to assess the cost-effectiveness of three different concepts for treatment: mandibular overdenture retained by a single (Group I; n = 11) or two implants (Group II; n = 13) and fixed hybrid prosthesis on four implants (Group III; n = 13). METHODS: Treatment effectiveness was measured as the 1-year before-after changes in patient satisfaction with the mandibular prosthesis. Costs were prospectively quantified from the perspective of the health provider, including all direct cost items attributed to the delivery of treatments and up to the 1-year follow-up, using a "bottom-up" costing estimation method. RESULTS: Patient satisfaction after treatment improved significantly for the three groups. The overall costs were R$ 2370.66, R$ 3185.21 and R$ 5739.52 for Groups I, II and III, respectively (P < .001). Analysis of incremental cost-effectiveness ratios suggested that the overdentures retained by one or two implants were more cost-effective than the fixed implant treatment, considering the mean cost and effectiveness values and the ±20% one-way sensitivity analysis. CONCLUSION: This study suggests that the incremental costs for the fixed hybrid prosthesis, compared to the overdenture treatments, is not proportional to the respective gain in effectiveness. Therefore, although all treatment options had satisfactory outcomes, the use of implants to retain a mandibular overdenture, irrespective of the use of one or two implants, is more cost-effective than the fixed implant treatment for the edentulous mandible.

A modified technique for the intraoral assessment of static occlusal contacts.

This article describes a procedure in which articulating paper is modified for the intraoral assessment of static occlusal contacts. The rectangular-shaped articulating paper is modified by creating parallel cuts at 2- to 3-mm intervals perpendicular to its long side without completely separating the paper. This modification may improve the accuracy in determining occlusal contacts and therefore facilitate an occlusal adjustment procedure.

Digital vs. conventional implant prosthetic workflows: a cost/time analysis.

OBJECTIVES: The aim of this prospective cohort trial was to perform a cost/time analysis for implant-supported single-unit reconstructions in the digital workflow compared to the conventional pathway. MATERIALS AND METHODS: A total of 20 patients were included for rehabilitation with 2 × 20 implant crowns in a crossover study design and treated consecutively each with customized titanium abutments plus CAD/CAM-zirconia-suprastructures (test: digital) and with standardized titanium abutments plus PFM-crowns (control conventional). Starting with prosthetic treatment, analysis was estimated for clinical and laboratory work steps including measure of costs in Swiss Francs (CHF), productivity rates and cost minimization for first-line therapy. Statistical calculations were performed with Wilcoxon signed-rank test. RESULTS: Both protocols worked successfully for all test and control reconstructions. Direct treatment costs were significantly lower for the digital workflow 1815.35 CHF compared to the conventional pathway 2119.65 CHF [P = 0.0004]. For subprocess evaluation, total laboratory costs were calculated as 941.95 CHF for the test group and 1245.65 CHF for the control group, respectively [P = 0.003]. The clinical dental productivity rate amounted to 29.64 CHF/min (digital) and 24.37 CHF/min (conventional) [P = 0.002]. Overall, cost minimization analysis exhibited an 18% cost reduction within the digital process. CONCLUSION: The digital workflow was more efficient than the established conventional pathway for implant-supported crowns in this investigation.

Complete digital workflow for the production of implant-supported single-unit monolithic crowns.

OBJECTIVES: The aim of this case series was to introduce a complete digital workflow for the production of monolithic implant crowns. MATERIAL AND METHODS: Six patients were treated with implant-supported crowns made of resin nano ceramic (RNC). Starting with an intraoral optical scan (IOS), and following a CAD/CAM process, the monolithic crowns were bonded either to a novel prefabricated titanium abutment base (group A) or to a CAD/CAM-generated individualized titanium abutment (group B) in premolar or molar sites on a soft tissue level dental implant. Economic analyses included clinical and laboratory steps. An esthetic evaluation was performed to compare the two abutment-crown combinations. RESULTS: None of the digitally constructed RNC crowns required any clinical adaptation. Overall mean work time calculations revealed obvious differences for group A (65.3 min) compared with group B (86.5 min). Esthetic analysis demonstrated a more favorable outcome for the prefabricated bonding bases. CONCLUSIONS: Prefabricated or individualized abutments on monolithic RNC crowns using CAD/CAM technology in a model-free workflow seem to provide a feasible and streamlined treatment approach for single-edentulous space rehabilitation in the posterior region. However, RNC as full-contour material has to be considered experimental, and further large-scale clinical investigations with long-term follow-up observation are necessary.

Implants versus short-span fixed bridges: survival, complications, patients' benefits. A systematic review on economic aspects.

AIM: To systematically evaluate the existing evidence to answer the focused question: For a patient with a single tooth to be replaced, is the implant crown, based on economic considerations, preferred to a conventional fixed partial denture? MATERIAL AND METHODS: PubMed MEDLINE, Cochrane-Central and Embase databases were searched using an extended list of search terms related to economics, which were then combined with the terms "prosthodontics" and "dental implant." RESULTS: The combined search for the "economic terms" and "prosthodontics" revealed 904 titles. The combination with "dental implants" revealed 2039 titles. Based on the abstracts, 73 full text publications were evaluated and data comparing outcomes with FDPs and implant crowns were retrieved from 26 publications. Initial costs for single implant crowns and FDPs on teeth were similar, but varied between tariff systems. The conditions of neighboring teeth and of the alveolar ridge defined the complexity (costs) of the treatment. Failure rates reported with single implant crowns and FDPs on teeth were similar. The long-term financial economic comparison showed a similar outcome for single implant crowns and FDPs. CONCLUSION: Other factors than costs and survival rates such as patient or provider reported factors may be more decisive when choosing between implant crowns and FDPs on teeth. The utility for the patient to keep healthy adjacent teeth unprepared makes the implant crown more economic.

Cumulative costs for the prosthetic reconstructions and maintenance in young adult patients with birth defects affecting the formation of teeth.

OBJECTIVES: To assess retrospectively the cumulative costs for the long-term oral rehabilitation of patients with birth defects affecting the development of teeth. METHODS: Patients with birth defects who had received fixed reconstructions on teeth and/or implants > or =5 years ago were asked to participate in a comprehensive clinical, radiographic and economic evaluation. RESULTS: From the 45 patients included, 18 were cases with a cleft lip and palate, five had amelogenesis/dentinogenesis imperfecta and 22 were cases with hypodontia/oligodontia. The initial costs for the first oral rehabilitation (before the age of 20) had been covered by the Swiss Insurance for Disability. The costs for the initial rehabilitation of the 45 cases amounted to 407,584 CHF (39% for laboratory fees). Linear regression analyses for the initial treatment costs per replaced tooth revealed the formula 731 CHF+(811 CHF x units) on teeth and 3369 CHF+(1183 CHF x units) for reconstructions on implants (P<.001). Fifty-eight percent of the patients with tooth-supported reconstructions remained free from failures/complications (median observation 15.7 years). Forty-seven percent of the patients with implant-supported reconstructions remained free from failures/complications (median observation 8 years). The long-term cumulative treatment costs for implant cases, however, were not statistically significantly different compared with cases reconstructed with tooth-supported fixed reconstructions. Twenty-seven percent of the initial treatment costs were needed to cover supportive periodontal therapy as well as the treatment of technical/biological complications and failures. CONCLUSION: Insurance companies should accept to cover implant-supported reconstructions because there is no need to prepare healthy teeth, fewer tooth units need to be replaced and the cumulative long-term costs seem to be similar compared with cases restored on teeth.

Economic aspects of single-tooth replacement.

The aim of this study was to assess and compare economic parameters of two treatment options in patients requiring single-tooth replacements in private practice. Thirty-seven patients received 41 conventional three-unit fixed partial dentures (FPDs). Fifty-two patients received 59 single crowns on implants (I). Treatment assignment was not random. All except one were metal ceramic reconstructions. All except one were crowns cemented on solid abutments of the ITI((R)) Dental Implant System. Economic parameters were noted for the preparatory phase, the actual reconstruction and for treatment of biological and/or technical complication thereafter (range 1-4 years): number of visits, chair-side time, treatment costs, costs for implant components and laboratory work. Costs were based on the tariffs between the Swiss dentists association and the insurers (Sfr 3.1 per tariff point). Implant treatment required more visits than FPD (8.1+/-2/4.8+/-2.3, chi(2): P=0.02). However, the total treatment time was similar (I: 4.8 h+/-0.9 h/FGM: 5.1 h+/-1.3 h, NS). Laboratory costs were higher for FPD (1527.8+/-209 SFr) vs. 579.6+/-106.9 CHF for I. Costs for treatment of technical and biological complications were similar. Total costs amounted to 3939.4+/-766.4 SFr for FGM vs. 3218+/-512.2 SFr for I (P<0.003, Kolmogorov-Smirnov). Even when considering opportunity costs (50 SFr) for each visit the implant solution was less expensive: 3623.2+/-656.1 SFr vs. 4178.7+/-822.1 SFr (P<0.04, Kolmogorov-Smirnov). Costs for treatment of complications were similar. In conclusion, over a short observation period, the implant reconstruction demonstrated a more favorable cost/effectiveness ratio. Especially in clinical situations with either non- or minimally restored teeth and sufficient bone, the implant reconstruction is to be recommended from an economical point of view.

Comparison between panoramic and intra-oral radiographs for the assessment of alveolar bone levels in a periodontal maintenance population.

BACKGROUND: Information about the agreement between intra-oral (I-O) and panoramic (OPG) radiographs is limited. AIMS: : (1) To assess the agreement between I-Os and OPGs for direct measurements of the distance between the cemento-enamel junction (CEJ) and the alveolar bone level (BL) as well as the proportional values in relation to the root length (CEJ-BL/root length), and (2) to explore the symmetry between the left- and right-side measurements. MATERIAL AND METHODS: I-Os and OPGs were studied in 292 periodontal maintenance subjects (mean age 55.5 years, SD+/-12.6) with on average 22.4 teeth (SD+/-4.1 range: 6-28). The images were measured using a PC software program. Site-based I-O and OPG values for CEJ-BL as well as CEJ-BL/root length were compared. OPG values of CEJ-BL/root length values between the left and right sides were also studied. RESULTS: A total of 11,395 linear distances (CEJ-BL plus CEJ-apex) from the I-Os and 21,462 linear distances from the OPGs were measured. The intra-class correlation coefficients (ICCs) between sets of readings of CEJ-BL varied between 0.80 and 0.89 (p<0.001), with the best agreement for tooth 22 (ICC: 0.89; 95% CI: 0.83-0.92). The ICCs for CEJ-BL/root length varied between 0.54 and 0.92. Mean differences between I-O and OPG values were in the 0.00-0.04 mm range for the CEJ-BL/root length comparisons. The maxillary anterior sextant demonstrated a 1.4 x enlargement by OPG for the CEJ-BL/root length comparisons. No distortions were observed for mandibular sextants. Left- and right-side symmetry of periodontal bone loss was demonstrated. ICC varied between 0.79 (95.00% CI: 0.71-0.84, p<0.01) and 0.53 (95.00% CI: 0.36-0.65, p< 0.01). CONCLUSIONS: I-O and OPG radiograph readings are in great agreement. Alveolar bone loss appeared to have a symmetrical distribution pattern. Hence for periodontal assessments, OPG radiographic readings may, at least in part, substitute for full-mouth periapical radiographic evaluation.