Evaluation of the aesthetic outcome of implant single-unit restorations with titanium and zirconia abutments using aesthetic indexesa: pilot study

Abstract

OBJECTIVES: Compare the aesthetic outcome of patients receiving one single-unit implant restoration in the aesthetic zone with titanium or zirconia abutments by means of aesthetic indexes and the subjective evaluation of the patients’ satisfaction. MATERIALS AND METHODS: The list of patients who received dental implants in the Dental Clinic of the Faculty of Medicine of University of Coimbra between 2005 and 2012 was reviewed and those who fulfilled the eligible criteria were asked to participate: (1) One single-unit implant restoration in the aesthetic zone (14-24) in situ, (2) with titanium or zirconia abutments and (3) natural adjacent and contralateral teeth. All gave their opinion regarding the aesthetic outcome of their situation through a Visual Analog Scale (VAS). The control visit consisted of taking a radiograph, photographs, filling in a clinical aesthetic assessment grid and impressions. The same investigator responsible for the collection of the information above evaluated the aesthetic outcome, both clinical and photographically. The photographs were handled to several professionals and students of the Dental Clinic, along with a grid similar to the one used clinically and a document explaining the indexes used (the PES/WES, the ICAI and the CIS), in order to measure the specialization effect. RESULTS: There is considerable agreement between the two evaluations (clinical and photographs), as well as a correlation between the evaluations given clinically and the mean score of those given based on photographs. According to this pilot study, the PES/WES index is the one with most internal consistency (Cronbach’s α=0.85); Aided by the software Amos, the soft tissue contour (0.78), the soft tissue level (0.68), the colour (0.8) and characterization of the crown (0.76), the position of the vestibular margin of the peri-implant mucosa (0.6), the colour and surface of the mucosa (0.54), symmetry/harmony (0.8) and colour of the crown (0.78) are the most influential parameters regarding the aesthetic outcome (RMSEA=0.019); The cases with zirconia abutments were assessed as being more aesthetic than the ones with titanium abutments. CONCLUSION: (1) Within the limitations of this pilot study, the PES/WES index appears to be the most consistent and probably the best to be implemented for the aesthetic outcome assessment of implant single-unit restorations. However, it lacks aspects related to overall aesthetics, such as the evaluation of lip line and considerations regarding the smile and facial harmony; (2) The protocol proposed is suitable to be employed when planning future rehabilitations and their subsequent assessment; (3) The most influential aspects should probably be those to which professionals should give more emphasis when planning an implant-single unit restoration to ensure its successful aesthetic outcome.