ORAL HEALTH EVIDENCE-BASED PRACTICE PROGRAM
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Title Implant-Assisted Mandibular Overdentures Do Not Lead to More Bone Resorption in the Opposing Maxillary Ridge When Compared to Conventional Mandibular Dentures
Clinical Question In an edentulous adult patient, do implant-assisted mandibular overdentures lead to more bone resorption in the opposing maxillary ridge compared to conventional mandibular dentures?
Clinical Bottom Line Two randomized controlled trials indicate that implant-assisted mandibular overdentures do not lead to greater bone resorption in the opposing maxillary ridge when compared to conventional mandibular dentures.
Best Evidence (you may view more info by clicking on the PubMed ID link)
PubMed ID Author / Year Patient Group Study type
(level of evidence)
#1) 10898841Närhi/200055 completely edentulous patientsRandomized Controlled Trial
Key resultsThere was a significant reduction in the width of the maxillary alveolar ridge in all measurement areas (mean difference = 0.4-0.6 mm; P<.0001). Changes were small and were not associated with the type of mandibular prosthesis. There was not a statistically significant difference between the bone resorption in the maxilla caused by a conventional mandibular denture compared to implant-supported overdentures on a transmandibular implant system or implant-mucosa-supported dentures on 2 IMZ implants.
#2) 18091171El-Dayem/200715 completely edentulous patientsRandomized Controlled Trial
Key resultsAfter 2 years, there was more bone resorption of the maxillary alveolar ridge in patients wearing conventional mandibular complete dentures when compared to patients wearing either a combined implant/mucosa-supported denture retained by a bar attachment on 2 implants or a mucosa-supported mandibular complete overdenture retained by magnetic attachment on 2 implants. The amount of bone resorption in the opposing arch in the group with mainly mucosa-supported mandibular overdentures (magnetic attachment on 2 implants) showed no significant difference during the follow-up period. The amount of bone resorption in the opposing arch in the group with combined implant-mucosa supported mandibular complete overdentures (a bar attachment on 2 implants) showed significant difference in the anterior and posterior areas after 1 and 2 years. The amount of bone resorption in the opposing arch in the group with a conventional mandibular denture was the greatest of the three groups.
#3) 21092056Tymstra/201145 completely edentulous patientsRandomized Controlled Trial
Key resultsAfter 10 years, there was significant bone resorption in the anterior maxilla in the two-implant group (mean difference = 0.12; P=0.003) and in the four-implant group (mean difference = 0.11; P=0.004). There was a similar bone resorption pattern in the anterior maxilla in all three groups. The amount of bone resorption in the anterior maxilla was not significantly different between the two-IMZ implant group, the four-IMZ implant group, and the conventional denture group.
Evidence Search ("bone resorption"[MeSH Terms] OR ("bone"[All Fields] AND "resorption"[All Fields]) OR "bone resorption"[All Fields]) AND implant[All Fields] AND ("dentures"[MeSH Terms] OR "dentures"[All Fields] OR "denture"[All Fields]) AND (("maxilla"[MeSH Terms] OR "maxilla"[All Fields] OR "maxillary"[All Fields]) AND ridge[All Fields] AND resorption[All Fields]) (“Dental Prosthesis, Implant-Supported/adverse effects"[MAJR] AND complete[All Fields])
Comments on
The Evidence
Validity: The three studies were randomized controlled trials with a total of 115 subjects between the three. Subjects were completely edentulous at the beginning of the study and were randomly assigned to three different groups: two of the groups were provided either implant-supported or implant/mucosa-supported prostheses (both considered types of implant-assisted prostheses) and the third group was treated with conventional dentures. All of the subjects were treated similarly and were provided adequate followup (2-year followup in the study by Abd El-Dayem, 6-year followup in the study by Närhi, and 10-year follow up in the study by Tymstra). It should be noted that the study by Närhi originally had 89 subjects but 34 subjects could not be included in the study, and the study by Tymstra originally had 120 subjects but 75 subjects could not be included in the study due to unwillingness to follow up, death, unclear reference points, and poor quality base-line or follow-up diagnostic casts.
Applicability According to the study by Abd El-Dayem the patients treated with conventional mandibular dentures showed the greatest amount of opposing-arch bone resorption compared to the patient groups treated with implant-assisted prostheses. The study by Närhi and the study by Tymstra did not show any significant difference in bone resorption when comparing conventional dentures to implant-assisted prostheses. Given that all three studies show that implant-assisted overdentures do not lead to more bone resorption when compared to conventional dentures, it would be beneficial to consider implants to aid in retention and stability when developing a treatment plan.
Specialty/Discipline (General Dentistry) (Prosthodontics)
Keywords Dental implant, overdenture, conventional denture, maxillary ridge resorption, edentulous
ID# 2855
Date of submission: 04/04/2015spacer
E-mail botto@livemail.uthscsa.edu
Author Antonella A. Botto
Co-author(s)
Co-author(s) e-mail
Faculty mentor/Co-author E. Matthew Lamb, DDS
Faculty mentor/Co-author e-mail lambem@uthscsa.edu
Basic Science Rationale
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