Objective: To investigate the argument’s validity that randomised control trials comparing high-viscosity glass-ionomer cement (HVGIC) placed using atraumatic restorative treatment, against amalgam or composite resin restorations (ART/RCTs) carry a confounder: a secondary comparison of incomplete against complete tooth excavation.
Methods: The logical validity of the relationships between the argument’s components was assessed. The empirical validity of its key-assumptions was appraised by systematic review. Key-assumptions were converted into 3 search questions: Do treatment techniques that rely on complete excavation using different materials follow the same treatment steps? Is incomplete excavation during ART directly related to the material properties of HVGIC? Do restorations placed, after incomplete excavation have a higher failure rate than after direct excavation? PubMed and GoogleScholar were search (December 28, 2016). Reference check, journal hand searching was conducted. Bias risk was assessed. Data was extracted from accepted trials and statistically analyzed.
Results: The relationship between the argument’s components was found logically valid but its underlying key-assumptions empirically invalid. The results suggest that: Differences in placement techniques are not unique to that between HVGIC/ART and amalgam or composite resin materials, but are also observable between that of amalgam and composite resin; HVGICs material properties appear appropriate to the consequences of incomplete excavation during ART; The current clinical evidence does not indicate a statistically significant higher failure rate of tooth restorations placed after incomplete excavation.
Conclusions: ART/RCTs appear not to contain a confounder. Future systematic reviews and future updates of existing systematic reviews, may consider the inclusion of ART/RCTs for appraisal.