Elsevier

Journal of Dentistry

Volume 39, Issue 10, October 2011, Pages 656-661
Journal of Dentistry

Three-year clinical outcome of single implant-retained mandibular overdentures—Results of preliminary prospective study

https://doi.org/10.1016/j.jdent.2011.07.007Get rights and content

Abstract

Objectives

The aim of this preliminary prospective study was to evaluate the clinical outcome, the oral health-related quality of life (OHRQoL), and the subjective chewing ability of patients with mandibular complete dentures retained by a single implant placed in the mandible midline.

Methods

Patients wearing complete dentures were treated with a single implant in the mandible, followed by relining of the dentures and incorporation of ball attachments for implant retention. Implant outcome, prosthodontic maintenance, subjective chewing ability, and the oral health impact profile of the patients were assessed at baseline and at four weeks after connecting the denture and implant.

Results

Eleven patients were enrolled in this investigation, and the mean observation period was 43.4 months (minimum period: 35, maximum period: 52 months). No implants were lost during observation period, but four dentures needed repair because of the fracture of the denture base in the midline area. A significant improvement was observed in the OHRQoL of the patients after the attachment of the mandibular dentures with a single midline implant. Furthermore, the subjective chewing ability of the patients was significantly improved after implant connection.

Conclusions

Within the limitations of this preliminary prospective clinical study, single implant-supported mandibular overdentures were a successful treatment option for older edentulous patients who showed improvements in their OHRQoL and chewing ability.

Introduction

In recent years, prevention measures with regard to caries and tooth loss were highly successful. However, edentulism is a present condition in the elderly generation in European countries.1 The Fourth German Oral Health Study reported that 30.5% of the seniors between the age of 65 and 74 years wore complete dentures in one jaw and at least 22.6% wore them in both jaws.2 The function and retention of complete dentures are often inadequate, mainly in the mandible. The quality of life and social relations of these patients are often reduced considerably.3, 4 General health and nutrition status of patients wearing complete dentures are also strongly associated with the oral rehabilitation status.5, 6 Furthermore, there exists a minority of patients who will never adapt to any conventional complete denture in the mandible without any fixation.7

Studies on mandibular dentures showed that dentures retained by two or more implants are more satisfactory than conventional dentures.5, 8, 9, 10, 11 International mutual consent was found that mandibular overdentures retained by two implants in the interforaminal area should be the first choice standard of care for the edentulous patient.12 However, because of the treatment costs of this standard implant therapy,13 many patients cannot afford treatment with two implants or are not willing to accept necessary bone augmentation procedures.

To limit costs, time, and effort, attempts were made to retain mandibular overdentures using only a single midline implant. Clinical studies show that the ability of a single implant placed in the mandibular midline to retain a complete denture is satisfactory during an observation period of up to five years.14, 15, 16, 17 Furthermore, lower component costs and treatment time with comparable satisfaction were reported by a randomized clinical trial, which compared mandibular overdentures retained by one or two implants.18 To assess patient satisfaction at baseline and after implant therapy, self-provided questionnaires on the basis of question-answer combinations16 or visual analogue scales (VAS)15, 17, 18 were used in previous studies. However, none of these studies provided information about the impact of single implant-retained denture therapy on the perceived oral health-related quality of life (OHRQoL) of the patients.

Therefore, the aim of the present study was to evaluate the clinical outcome of single implant-retained overdentures in the mandible of patients and to assess the patients’ OHRQoL and subjective chewing ability of hard and soft food at baseline and after implant therapy.

Section snippets

Materials and methods

This investigation was approved by the Ethical Committee of the Medical Faculty of the Christian-Albrechts University of Kiel, Germany. Written informed consent was obtained from all participating subjects. Patients who had received complete dentures at the Department of Prosthodontics, Propaedeutics, and Dental Materials and who met the following inclusion criteria were included in the investigation1: Patients with complete dentures in the maxilla and mandible, which were technically

Results

From 2006 to 2007, 11 patients (five women and six men; mean age: 66.7 years; minimum age: 51, maximum age: 86 years) were enrolled in this investigation.

The mean observation period was 43.4 months (minimum period: 35 and maximum period: 52 months). One male patient died 35 months after implantation. Between implantation and last follow-up examination of this patient, six months postoperative no complications were observed or reported by the patient.

During the observation period, no implants

Discussion

In the present investigation, the clinical outcome of single midline implant-supported mandibular overdentures was investigated. The investigated parameters were osseointegration of the supporting implants and changes in the OHRQoL and subjective chewing ability of the patients, before and after implant-attachment of the overdentures. Furthermore, the adjustments and repairs of the overdentures that occurred during the observation period were recorded. Oral health related quality of life and

Conclusions

Within the limitations of this study, the following conclusions could be drawn: Central single implant-supporting mandibular dentures show a good clinical outcome after three years; after implant connection, significant improvement in the OHRQoL and subjective chewing ability of hard and fibred food was observed in the patients.

Acknowledgements

This study was supported by a grant from Camlog Biotechnologies AG, Basel, Switzerland. The authors further want to thank the dentists of the department who were involved in the study.

References (35)

  • N.U. Zitzmann et al.

    What is the prevalence of various types of prosthetic dental restorations in Europe?

    Clinical Oral Implants Research

    (2007)
  • J. Fiske et al.

    The emotional effects of tooth loss in edentulous people

    British Dental Journal

    (1998)
  • A. Dudic et al.

    Retention mechanisms and prosthetic complications of implant-supported mandibular overdentures: long-term results

    Clinical Implant Dentistry and Related Research

    (2002)
  • A. Visser et al.

    Mandibular overdentures supported by two or four endosseous implants

    Clinical Oral Implants Research

    (2005)
  • J.S. Feine et al.

    The McGill consensus statement on overdentures. Mandibular two-implant overdentures as first choice standard of care for edentulous patients. Montreal, Quebec, May 24–25, 2002

    International Journal of Oral and Maxillofacial Implants

    (2002)
  • J.N. Walton et al.

    Cost analysis of fabricating implant prostheses

    International Journal of Prosthodontics

    (1996)
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