Plain English Summary
Background and study aims
Overdentures, also known as dental implants, are metal posts which are screwed directly into the jaw bone in order to support replacement teeth. Abutments are connectors that are placed on the top of a dental implant to connect the implant to the replacement tooth. Mini-implants have been successfully used to support complete dentures in edentulous patients (patients with no natural teeth) that have wasting (or resorption) of the bone holding the teeth (alveolar bone). The aim of this study is to see whether mini-implants with an angulated abutment (that is, an abutment placed at a different angle to the denture) is better than
a non-angulated abutment (that is, an abutment placed at the same angle than the denture).
Who can participate?
Patients who, having responded to an advertising campaign, have no natural teeth and have ill-fitting dentures due to resorption of the alveolar bone.
What does the study involve?
Participants are randomly allocated to one of two groups. Those in group 1
receive a non-angulated abutment. Those in group 2 receive angulated abutment. Alveloar bone height is measured 6 mnoths after treatment and again at 12, 18 and 24 months.
What are the possible benefits and risks of participating?
The use of mini-implants with non-angulated abutment may provide benefits for patients such as a stable, immediately functional aesthetic for overdentures for patients with wasting of the alveolar bone. There are no reported risks to taking part.
Where is the study run from?
Al-Azhar University, Faculty of Dentistry (Egypt)
When is the study starting and how long is it expected to run for?
October 2012 to December 2014
Who is funding the study?
Albaha University (Saudi Arabia)
Who is the main contact?
1. Professor Khalid Arafa (scientific)
2. Dr Hashim Ahmed (public)
Effects of angulated and non angulated mini-implants abutment supporting mandibular overdenture on peri-implant bone height
The mini-implants with angulated abutment is better than non-angulated abutment
Dental Health Department at the Faculty of Applied Medical Sciences, Albaha University.
Randomized two-arm parallel design
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet
Mini-implants used to support complete dentures in edentulous patients with little bone width or length.
One of the initial steps in non-angulated mini-implant insertion include the use of a surgical stent to the determined position of the abutment with four holes. Participants in this study were randomly allocated to one or two groups.
1. Group 1: received lower overdentures with non-angulated abutment. A non-angulated abutment means there is overstructure without any changes in angle of the abutment.
2. Group 2: received lower overdentures with angulated abutment, which means the angulated abutments were essential to redirect the screw holes in a communal pathway of attachment to help in the fabrication and fitting of the prosthesis. Furthermore, the abutments were utilized to redirect these holes in the lingual path. Lastly, in specific cases, it may not be possible to redirect and fabricate the screw with an angle of pre-fabricate 45° angulated abutments (selecting direction is easy with the octa 45° rotation angles).
Bones were evaluated for height after 6, 12, 18, and 24 months with panoramic x-ray. The mini-implants used were manufactured by Dentium, Slim Line, No: SDM1304.
Primary outcome measure
Alveolar bone height, measured after 6 months with panoramic x-ray.
Secondary outcome measures
Alveolar bone height, measured after 12, 18, and 24 months with panoramic x-ray.
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
Patients with a lower flat ridge due to completely edentulous maxillary and mandibular ridges with resorbed ill-fitted lower dentures
Target number of participants
30 patients responded to an advertisement campaign, but only 20 patients met the selection criteria
Participant exclusion criteria
Patients without a lower flat ridge due to completely edentulous maxillary and and mandibular ridges
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Assiut Branch Faculty of Dentistry
Albaha University (Saudi Arabia)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Intention to publish date
Participant level data
Available on request
Basic results (scientific)