Cost-effectiveness of Implant Treatment for the Edentulous Mandible (CEAIMPLANT)

The aim of this study is to assess the cost-effectiveness of the mandibular overdenture retained by one and two implants and the mandibular fixed prosthesis retained by four implants, based on a randomized clinical trial.

This randomized clinical trial alongside a cost-effectiveness analysis will include 48 edentulous individuals who meet eligibility criteria. Participants will receive conventional complete denture treatment and will be randomized into three groups: single-implant mandibular overdenture group, mandibular overdenture retained by two implants, and fixed mandibular prosthodontics retained by four implants. CBCT and panoramic radiographs will be obtained to assess if bone sites in three-dimensional terms have a minimum volume for receiving implants of at least 3.75 x 9 mm. All patients will receive Titamax IT Cortical implants (Neodent, Curitiba, Brasil) and correspondent prosthodontic components - O'ring/ball abutments for overdentures. Satisfaction with the dentures and oral health-related quality of life impacts will be considered the measures of effectiveness for the three interventions. Cost assessment and cost-effectiveness analysis will be performed from the healthcare provider perspective. Further analysis will be performed using the patient's perspective, in which the costs will be estimated according to the reference price of dental procedures and treatments of the Brazilian Dental Association (Hierarchical Brazilian Classification of Dental Procedures - CBHPO) and the gross costs will be obtained from a panel of experts. Quantification and costing of the resources will be carried out in three steps: identification of the relevant costs to the assessment; measurement of the resources used; and valuation of the resources. The costs will be calculated in Brazilian currency for each patient until one year after treatment. Incremental cost-effectiveness ratios will be calculated to assess the incremental cost for each unit of effectiveness.

A 10 cm uninterrupted visual analogue scale will be used in order to assess the participants' ratings of their satisfaction with the upper and lower dentures in relation to the parameters "general satisfaction", "comfort", "stability", "aesthetics", "ability to speak" and "ability to chew".

Oral Health Impact Profile Instrument for edentulous subjects (OHIP-EDENT) in order to assess the impact of oral health conditions on quality of life of participants.

Masticatory efficiency will be assessed as a secondary outcome using a two-colored chewing gum test and a qualitative and quantitative colourimetric method to measure the color-mixing ability.

Inclusion Criteria: No contraindications for implant surgery (mainly related to uncontrolled systemic diseases) Present enough bone volume in the mandible for implant placement without the need of bone augmentation procedures. Be able to understand and answer the questionnaires used in the study Agree to participate by providing a written informed consent. Exclusion Criteria: Noncompliant participants Individuals who do not agree to be randomly allocated to the treatment study group Presence of signs of untreated temporomandibular disorders, uncontrolled systemic or oral conditions that require additional treatments

Nogueira TE, Esfandiari S, Leles CR. Cost-effectiveness analysis of the single-implant mandibular overdenture versus conventional complete denture: study protocol for a randomized controlled trial. Trials. 2016 Nov 4;17(1):533. doi: 10.1186/s13063-016-1646-0.