Patient-Centered Risk Assessment in Implant Treatment Planning.

PURPOSE: To evaluate the current scientific evidence on estimating cumulative risk for biologic complications relating to dental implants and to develop a patient-centered risk assessment tool for establishing aggregate risk. MATERIALS AND METHODS: A review of the scientific literature on risk indicators relating to dental implants was completed with the goal of identifying and weighting individual risk indicators so aggregate biologic risk could be estimated. Three authors completed independent reviews of the literature, identifying 31 systematic reviews on risk indicators for biologic complications with dental implants, from which 24 potential risk indicators were considered. Due to inconclusive scientific data on risk indicators, a Delphi process was used to gather structured expert opinion to supplement findings from the literature. Eleven Delphi participants with expertise in prosthodontics or periodontics participated in two email exchanges and one face-to-face meeting to comment and debate on the initial identification and weighting of risk indicators, propose the addition or removal of risk indicators, and provide recommended clinical management for each risk indicator. RESULTS: After three rounds of debate, literature review, and additions and removals of various risk indicators, consensus (defined as 95% or more in agreement) was achieved on 20 risk indicators. The Delphi group concluded that the risk indicators of smoking, diabetes, antiresorptive agents, and cemented restorations should include subcategories to more accurately identify and represent patient-specific risk. Clinical recommendations based on individual and aggregate risk were established by consensus. CONCLUSION: The literature on risk indicators for biologic complications was conflicting and inconclusive. The Delphi method was used to identify and establish the weighting of individual risk indicators, resulting in a risk assessment tool for estimating aggregate risk.

Measuring the Monetary Value of Dental Implants for Denture Retention: A Willingness to Pay Approach.

PURPOSE: Two interforaminal dental implants in is a common treatment option for denture retention in edentulous patients. Economic methods to assess the patient's quality of life include the willingness to pay (WTP) for implant treatment and willingness to accept (WTA) to forgo implant treatment. The purpose of this study was to assess the monetary value of implant retained complete dentures using WTP and WTA. METHODS: We included a convenience sample of 16 patients from a previously published cohort study on the survival of immediately loaded implants in edentulous patients to assess WTP and WTA for this treatment option. RESULTS: The average maximum WTP for implant treatment was 4606 (95% CI: 2991-6222) Swiss Francs. Out of the 16 patients, only 5 were willing to trade their implants for money, with a mean WTA of CHF 33'500 (range: 3000-100'000).All patients would agree to undergo the implant surgery procedure again. CONCLUSION: The results of the present study show that most patients are not willing to trade the increase in quality of life after implant surgery against money, suggesting that WTA exceeds by large WTP for the same health condition.

Ektodermale Dysplasie.

Ectodermal dysplasias (EDs) form a large clinically and genetically heterogeneous group of manifestations characterized by dystrophy or agenesis of embryologic ectodermal derivatives. Therefore skin, nails, hair, teeth and secretory organs are mainly affected. Hypohidrotic ectodermal dysplasia (HED) is the most common ED syndrom. It is characterized by atrichosis or hypotrichosis, anodontia or hypodontia and hypohidrosis. Missing teeth or retarded eruption of teeth often leads to the diagnosis of ED, which emphasizes the significance of an appropriate dental examination. Tooth agenesis and its effects on craniofacial structures are often the most signicificant clinical and therapeutical problem. It is a challenge to manage the functional, esthetic and psychosocial needs of these patients and therefore requires the involvement of different specialists, such as pediatrists, pedodontists, oral surgeons and prosthodontists.

CAD-CAM-Anwendung in der Totalprothetik CAD-CAM-Anwendung in der Totalprothetik CAD-CAM-Anwendung in der Totalprothetik.

The combination of scanning technology and CAD/CAM procedures allows to significantly reduce working time clinically as well as for the dental laboratory. In comparison to conventional complete denture fabrication, the AvaDent® system provides specific trays and registration plates to complete all the required patient recordings and steps in the first appointment. By virtual modeling (CAD) and milling of the denture (CAM) out of a solid acrylic puck, time-consuming flasking and packing procedures are needless. Due to the abscence of any polymerisation shrinkage of the dentures, the precision of fit remains accurate. This system allows to efficiently deliver high-quality and cost-effective complete dentures for the edentulous patient in only two appointments. The clinical procedure is presented step-by-step and critically evaluated from the clinician’s point of view.

The effect of tooth loss on gait stability of community-dwelling older adults.

OBJECTIVE: To investigate the effects of tooth loss on gait stability in a healthy elderly population. METHODS: A case-control study was conducted among healthy and prosthetically well-restored seniors over the age of 65 years. The test group comprised 24 edentulous participants who were restored with complete dentures in the upper jaw and an overdenture fixed on two implants in the lower jaw. The control group comprised 25 dentate participants who either still had their natural teeth or were restored with conventional fixed partial dentures. Gait stability was evaluated by measuring the parameters 'gait velocity' and 'cycle-time variability' during self-selected normal walking speed and under dual-task performance conditions. Measurements were conducted using the GAITRite(®) electronic walkway system. RESULTS: Dentated and fixed restored participants (the control group) had a significantly higher gait velocity compared with denture wearers (the test group) under both normal walking (p = 0.03) and dual-task performance conditions (p = 0.01). In each test condition, among edentulous participants, gait velocity did not significantly differ according to whether the participant wore their dentures. CONCLUSION: The present results suggest that tooth loss in healthy seniors is associated with lower gait velocity and therefore may have a negative impact on gait stability.

[prepCheck computer-supported objective evaluation of students preparation in preclinical simulation laboratory]. / prepCheck computergestützte objektive Beurteilung von Zahnpräparationen im Simulationslabor.

Applications such as “prepCheck” allow objective and consistent judgments of tooth preparations. Hereby the respective preparation is matched with a standardized preparation. Whereas the learning curve in the beginning is time-consuming, after some time the faculty members will be relieved from additional mentoring time in the preclinical simulation laboratory. Students independently get an objective self-assessment by the software. Time and effort at the moment are in a misbalance since three scans (preparation, occlusion record, opposite jaw) are necessary. A simple one-scan procedure would be preferable. “prepCheck” is considered as a user-friendly software. It will play an essential role in the objective assessment of students tooth preparations in the future education.

[Digital implant impression taking - an overview]. / Digitale Implantatabformung.

In dentist's daily practice, intraoral scanning systems are increased. Besides scanning of prepared teeth, also implants could be scanned intraorally. This clinical report describes the step-by-step techniques to scan digitally intraoral implants with two intraoral scanners (Lava™ C.O.S., 3M Espe and the CEREC AC connected with inLab MC XL, Sirona) for generating implant suprastructures without the use of impression materials, dental stone or implant impression copings. Different workflows, possibilities and limits by scanning dental implants are demonstrated.

Markov models in dentistry: application to resin-bonded bridges and review of the literature.

Markov models are mathematical models that can be used to describe disease progression and evaluate the cost-effectiveness of medical interventions. Markov models allow projecting clinical and economic outcomes into the future and are therefore frequently used to estimate long-term outcomes of medical interventions. The purpose of this paper is to demonstrate its use in dentistry, using the example of resin-bonded bridges to replace missing teeth, and to review the literature. We used literature data and a four-state Markov model to project long-term outcomes of resin-bonded bridges over a time horizon of 60 years. In addition, the literature was searched in PubMed Medline for research articles on the application of Markov models in dentistry.

Immediate loading of two unsplinted mandibular implants in edentulous patients with an implant-retained overdenture: an observational study over two years.

OBJECTIVES: Immediate loading of two unsplinted mandibular implants by means of an overdenture may be a viable and cost-effective treatment option to improve the patient's oral health-related quality of life. We therefore conducted a prospective observational study to estimate implant survival and patient satisfaction after an immediate loading protocol in edentulous patients. MATERIALS AND METHODS: Twenty edentulous patients who received two interforaminal implants (Straumann Standard implant, length 12 mm) were included in our study. Immediately after implant placement, ball attachments with a diameter of 2.25 mm were placed on the implants and the respective matrices were directly incorporated in the existing complete denture. Clinical recalls were scheduled 1 week, 1, 3, 6 months, and 1 and 2 years after implant placement. The following clinical parameters were assessed: gingival bleeding index (GBI), visual plaque index (VPI), and soft tissue overgrowth. In addition, we also assessed radiological bone level change (RBLC) using panoramic radiographs, and patient satisfaction using a visual analogue scale at baseline, after 6 months and 2 years. RESULTS: No implant failures occurred during the 2-year observation period, resulting in a survival rate of 100%. The mean RBLC was 0.67 mm (95% Confidence Interval [95% CI]: 0.47-0.86 mm) two years after surgery. The GBI and VPI after two years were 24 (95% CI: 9-38)% and 36 (95% CI: 19-53)%, respectively. Soft tissue overgrowth was 1.6 mm (95% CI: 1.1-2.1) on average after two years. In a multivariate regression model, patients with a GBI ≥50% on average showed an increased RBLC (-0.6 mm, p = 0.007). High patient ratings were recorded for overall satisfaction. Overall patient satisfaction measured on a scale between one and ten was 5.2 (95% CI: 2.1-8.5) before implant placement and 9.5 (95% CI: 9.1-10) after 2 years. CONCLUSION: Immediate loading of two unsplinted interforaminal implants in overdenture patients using ball attachments is a clinically viable treatment option that leads to a high survival rate and oral health-related quality of life.

Wear of ceramic and titanium ball attachments in subjects with an implant-retained overdenture: a controlled clinical trial.

STATEMENT OF PROBLEM: Loss of retention of implant-retained overdentures due to wear of the patrix or matrix of the attachment system is a common clinical problem. PURPOSE: The purpose of this controlled clinical trial was to compare the wear of ceramic and titanium ball attachments and their corresponding gold matrices after 1 year of clinical function in subjects with implant-retained mandibular overdentures. MATERIAL AND METHODS: Forty subjects who had been treated with a 2-implant-retained overdenture received either 2 ruby ball attachments (20 subjects) or 2 titanium ball attachments (20 subjects). The diameter of the ball attachments and the thickness of the matrix were measured optically before insertion and after 1 year of clinical function. Differences among groups were then compared with the Wilcoxon rank sum test (α=.05). To estimate any correlation between clinical parameters and wear, the Spearman rank test was used. RESULTS: There was no significant difference (P=.73) in the median wear of ball attachments for the titanium group (5.3 µm; median 1.3 µm) and for the ceramic group (1.3 µm; median 1.3 µm). In the ceramic group, a fracture rate of 30% was observed. The mean wear of the matrices in the titanium group was 3.1 µm (median 6.8 µm) and in the ceramic group 2.1 µm (median 3.4 µm), P=.01. No correlation was found between ball attachment wear and matrix insert wear (Spearman rank test). Wear of matrices was weakly correlated with an increase in divergence between implant axes in the sagittal plane (P=-.28 and P=.021). Ball attachment wear was associated with an increase in divergence between matrix axes in the sagittal plane (P=-.34 and P=.047). CONCLUSIONS: Matrices on ceramic ball attachments showed less wear than those placed on titanium ball attachments. However, the use of ruby ball attachments cannot be recommended because of a high fracture rate.

[Zirconia in removable prosthodontics. A case report]. / Zirconiumdioxid in der abnehmbaren Prothetik. Ein Fallbericht.

Zirconia as a framework material is well established in fixed prosthodontics. However, for its application for removable dentures little experience exists. Zirkonzahn® has developed a copy-milling unit, that is a manually operated machine for the manufacture not only of frameworks but also of complete removable dentures. The aim of this case report is to show the step-by-step clinical and technical fabrication of a zirconia bar on implants and of a corresponding zirconia complete denture. The advantages and disadvantages of the system are presented and problems are critically discussed.

[How up-to-date are metal-based resin-bonded fixed partial dentures in the era of full-ceramics and dental implants? A case report]. / Wie aktuell sind metallkeramische Adhäsivbrücken im Zeitalter der Vollkeramik und der Implantologie? Ein Fallbericht.

Regardless of the success of preventive measures the replace¬ment of missing teeth in young patients with caries-free dentitions is a daily challenge for the clinician. The decision-making process concerning the different treatment options is difficult, based on several equivalent solutions. Thereby the significance of minimal invasive approaches is steadily increasing. In indicated cases, resin-bonded fixed partial dentures which were introduced in the last century still represent a well documented and minimally invasive procedure, even in the era of dental implants. In this article, clinical aspects of a conventional, metal-based resin-bonded fixed partial dentures are discussed according to the current literature and the clinical steps are presented in a clinical case.

Estimating long-term survival of densely sintered alumina crowns: a cohort study over 10 years.

STATEMENT OF PROBLEM: Alumina-core crowns have become a standard treatment option in contemporary dental practice. The short-term survival of alumina crowns has been well documented. However, there is still a paucity of long-term survival data. PURPOSE: The purpose of this prospective cohort study was to estimate long-term survival of alumina crowns in anterior and posterior areas over an observation period of up to 10 years. MATERIAL AND METHODS: Between 1997 and 2005, 155 alumina crowns were placed in 50 subjects. Clinical and technical parameters were assessed at baseline. In 2005 and 2008, the crowns were clinically assessed using modified U.S. Public Health Service (USPHS) guidelines. Treatment failure was defined as crown or tooth loss and separated into technical or biological failures. Survival probabilities were estimated using the Kaplan-Meier method. RESULTS: In 2008, 29 subjects with 112 alumina crowns, including 86 (77%) posterior and 26 (23%) anterior crowns, were available for clinical assessment. The average observation period for these subjects was 7.8 years, with a range from 3 to 10.7 years. In total, 3 technical and 8 biological failures were observed. The estimated survival probability considering technical failures only was 95% (95% Confidence Interval (CI), 89% to 100%). The estimated overall survival probability after 10 years was 84% (95% CI, 74% to 95%). There was no significant difference in treatment failures in posterior as compared to anterior crowns (all failures: P=.713; technical failures: P=.352). CONCLUSIONS: The results suggest that the expected 10-year survival rate of alumina crowns due to technical failures is 95% (95% CI, 89% to 100%).

[Locator or ball attachment: a guide for clinical decision making]. / Locator oder Kugelanker? Eine Hilfe für die klinische Entscheidungsfindung.

Various attachments are available to retain overdentures on natural roots or implants. Technical aspects, the clinical handling, the capability to adapt or repair and the costs are parameters to be considered when choosing the appropriate attachment. Ball attachments and bars are clinically established and well documented. Ball attachments as prefabricated, unsplinted units are easily replaceable and show hygienic advantages, while bars show favorable stability. The Locator is a newer, popular clinical alternative to these established attachments. The ball attachment and the Locator are compared from a technical and clinical point of view.

[The interdisciplinary fixed restoration of an edentulous maxilla with a marked resorption of the alveolar crest. A case report. Part II: the definitive restoration]. / Die interdisziplinäre festsitzende Rekonstruktion eines zahnlosen Oberkiefers mit ausgeprägter Resorption des Alveolarfortsatzes. Ein Fallbericht. Tell 2: Die definitive Rekonstruktion.

Different materials and methods can be used for edentulous maxillae rehabilitations. A precise fit between the implant and the framework is assumed. Hence, often implant suprastructures made by conventional lost wax techniques lack such a fit and a secondary modification is necessary. Alternatively the CNC-milling technique provides implant frameworks with a passive fit made of titanium and recently also of zirconia. This article describes the fabrication of a fixed complete dental prosthesis supported by seven implants in an edentulous maxilla. Two prostheses were fabricated, one made of a titanium framework veneered with resin and one made experimentally of a zirconia framework veneered with ceramics. The clinical and technical steps are documented and discussed.

[The interdisciplinary fixed restoration of an edentulous maxilla with a pronounced resorption of the alveolar crest. A case report. Part I: The immediate reconstruction]. / Die interdisziplinäre festsitzende Rekonstruktion eines zahnlosen Oberkiefers mit ausgeprägter Resorption des Alveolarfortsatzes. Ein Fallbericht. Teil 1: Die Sofortversorgung.

Edentulous patients wearing a conventional complete denture often request a fixed restoration for functional, esthetical and/or psychosocial reasons. For these patients implant-supported fixed dental prostheses are a prosthetic means of choice. However, after years of edentulism often a marked resorption of the alveolar crest has taken place, asking for bone augmentation before implant placement. Thus, fixed implant reconstructions are time and cost intense and stressful for the patient. This case report documents the immediate fixed reconstruction in the edentulous maxilla after ridge augmentation with a cortical cancellous bone graft from the iliac crest and implant placement. A CAD/CAM-system was used for implant planning and the fabrication of a drilling guide. The prosthetic reconstruction was inserted immediately after implant placement.