Iatrogenic Damage From Orthodontic Composite Removal: a 3D Metrology Pilot Study

Objectives: The resemblance in appearance between dental composites and natural teeth is crucial for aesthetic treatments. However, when composite restorations need to be drilled out, this similarity can lead to iatrogenic tooth damage or incomplete composite removal. Our research aimed to optimize the use of intraoral scanning and 3D metrology to evaluate composite removal and potential factors contributing to iatrogenic tooth damage.
Methods: Nine experienced dentists were asked to remove composite restorations from upper anterior artificial teeth. Intraoral scanning captured tooth surfaces before and after composite removal, generating STL files for 3D mesh comparison. A mixed statistical analysis model evaluated potential factors affecting composite removal, including the type of tooth, burr, and composite shade.
Results: All teeth showed some degree of iatrogenic tooth damage and remanence of composite. An average of (2.69 ± 1.86) mm³ remaining composite per tooth was observed, while the average volume of the damaged tooth structure per tooth was (1.29 ± 1.35) mm³. Tooth type, composite shade, and dentist showed no significant associations with iatrogenic damage or remanence of composite (p>0.05), while bur type was significantly associated (p=0.012).
Conclusions: The use of intraoral scanning and 3D metrology allows for assessing the success of composite removal procedures. This study revealed that complete composite removal without causing iatrogenic tooth damage is unavoidable. Moreover, the type of bur used can significantly affect the success of such procedures.