Carlo P. Marinello

Treatment plan for restoring the edentulous maxilla with implant-supported restorations: Removable overdenture versus fixed partial denture design

STATEMENT OF PROBLEM Restoring the edentulous maxilla with a fixed complete denture or a removable overdenture is a complex and challenging procedure. PURPOSE This article presents and discusses the crucial factors involved in deciding whether a fixed or removable implant prosthesis should be planned in fulfilling the patients preference for optimal esthetics, phonetics, comfort, and function. METHODS AND MATERIAL A concept for treatment planning is presented that enables the practitioner to check the decisive parameters during the first examination and to make the final decision with the help of the reformatted computerized tomography scan. CONCLUSION If this treatment plan is followed, implants can be placed to comply with the selected prosthetic solution and compromised solutions can be avoided. The fixed design for implant prosthesis is only appropriate for patients with minimal resorption of the alveolar bone and an optimal maxillomandibular relationship. The removable overdenture may be indicated from the outset and is no longer restricted to patients with a compromised situation in which fixed implant prostheses are not feasible.

A Cost-effectiveness Analysis of Implant Overdentures

Placement of dental implants may improve the retention and stability of complete dentures in edentulous patients. Treatment costs, however, substantially increase with implant treatment. We therefore performed a stochastic cost-effectiveness analysis, comparing implant-supported over-denture prostheses (4 implants), implant-retained overdentures (2 implants), and complete dentures, from the patient’s perspective in Switzerland, to assess whether implant treatment in the mandible represents value for money spent. Twenty patients were included in each treatment group and were followed up for three years. Health outcomes were expressed in Quality-adjusted Prosthesis Years, and dental health care costs and time costs were recorded in year 2000 Swiss Francs (CHF 100 = US

Treatment outcomes of fixed or removable implant-supported prostheses in the edentulous maxilla. Part II: Clinical findings ☆

61). The cost per Quality-adjusted Prosthesis Year gained for implant treatment was CHF 9100 (2 implants) and CHF 19,800 (4 implants) over 3 years. Over a ten-year period, these threshold ratios were reduced to CHF 3800 (2 implants) and CHF 7100 (4 implants) per Quality-adjusted Prosthesis Year gained.

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

STATEMENT OF PROBLEM There is a widespread belief that maxillary overdenture prostheses are associated with a higher frequency of complications and require more maintenance than fixed implant prostheses. PURPOSE This prospective clinical study compared the treatment outcomes of fixed and removable implant-supported restorations in the edentulous maxilla with the main emphasis on the clinicians point of view. MATERIAL AND METHODS Ten patients were treated with fixed screw-retained implant prostheses (group 1), and 10 patients were treated with removable implant-supported overdentures (group 2) in the edentulous maxilla. Recall was scheduled at 6-month intervals to investigate the prosthodontic treatment outcomes, including implant survival, prosthesis time until retreatment, and maintenance issues. Clinical parameters gingival index (GI), plaque index (PI), the clinical attachment level, and radiographic marginal bone levels measured, along with any biologic and mechanical complications were recorded. RESULTS Patients were followed over a mean period of 39 months (SD=7; group 1) and 27 months (SD=10; group 2) after implant placement. Cumulative implant survival was 97.6% for group 1 and 94.4% for group 2 after an 18-month observation period. The mean time until retreatment after prostheses insertion was 23.4 months for group 1 and 19.8 months for group 2 (n.s.). In both groups, the increase over time in the radiographically investigated bone level was found to be significant. The indices given for the mucosal health and oral hygiene status (GI and PI) were highly correlated in both groups at each recall appointment, but no significant differences were found between groups 1 and 2. CONCLUSION In groups 1 and 2, comparable prosthodontic treatment outcomes were achieved. The majority of mechanical complications could be managed chairside during recall visits and did not require additional appointments, so that the time and costs involved in providing maintenance were kept down.

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

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%).

Do healing abutments influence the outcome of implant treatment? A three-year multicenter study

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.

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

STATEMENT OF THE PROBLEM It is not known if healing abutments replaced subsequently with permanent abutments adversely affect the soft tissues and marginal bone levels around dental implants. PURPOSE This study evaluated the mucosal condition and marginal bone levels 3 years after placement of healing abutments in patients provided with fixed prostheses supported by Brånemark implants. MATERIAL AND METHODS Data were analyzed retrospectively from 117 patients treated at five centers in which 318 healing abutments were placed on maxillary and 112 on mandibular implants. A prospective 3-year appraisal with a specific protocol assessed the response of mucosal cuffs and marginal bone levels surrounding surviving implants. RESULTS Exchange of abutments did not affect expected survival rates of implants (94% maxilla, 99% mandible) or produce mean levels of marginal bone loss greater than anticipated for the system. Mean marginal bone levels correlated significantly with the jaw. Most patients achieved good oral hygiene and favorable peri-implant soft tissue health. CONCLUSION No evidence was found to suggest abutment exchange adversely affects outcome of implant treatment.

Health State Utilities in Edentulous Patients: A Time Trade-off Approach

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.

Academy of Prosthodontics centennial: The emergence and development of prosthodontics as a specialty

Background: Health is generally regarded as a very high good, and oral health may substantially affect the quality of life of patients. Oral health–related quality of life has usually been investigated by means of disease-specific descriptive instruments, such as the Oral Health Impact Profile and the General Oral Health Assessment Index. These instruments, however, do not enable a comparison of oral health–related quality of life with other medical diseases. Economic methods, such as the time trade-off technique, enable a comparison of the impact of oral health with other medical diseases and thus provide a means to build a bridge in quality-of-life assessments between medicine and dentistry. Methods: We included in our study a total of 58 patients who received a complete denture in our clinic in the last 10 y (between January 2001 and May 2012) and who were ≥65 y old. Patient preferences for the edentulous and poorest imaginable oral health state were assessed via the time trade-off method. Results: Edentulous patients rated their current oral health state as 0.73 (SD, 0.25) and the poorest oral health state as 0.43 (SD, 0.33) on a scale between 0 (death) and 1 (best possible health state). These results are comparable to patient preferences for other serious diseases, such as breast cancer (0.75), asymptomatic HIV infection (0.69), depression (0.44), and osteoarthritis of the hip (0.44). Conclusion: In conclusion, our results suggest that oral health may substantially affect quality of life no less than other medical diseases. Knowledge Transfer Statement: Health is generally considered the highest good of humankind. In the present article, we show that oral health substantially affects quality of life. In particular, we show that loss of teeth (i.e., being edentulous) reduces quality of life no less than other systemic diseases. Treatment modalities for the edentulous patient may therefore substantially improve the patient’s well-being and should be a research priority.

Experimental peri‐implant mucositis in man

Author(s): Wiens, Jonathan P; Koka, Sreenivas; Graser, Gerald; White, Shane N; Marinello, Carlo P; Curtis, Donald A