Effect of replacement of dental amalgam on oral lichenoid reactions

Objectives: The objectives of this study were to investigate (i) healing of oral lichenoid reactions (OLR) following the selective replacement of restorations of dental amalgam, (ii) whether there were differences in healing between contact lesions (CL) and oral lichen planus (OLP), and (iii) whether there was a difference in healing potential when different materials were selected as a substitute for dental amalgam. Methods: Patients included in the study presented with OLR confined to areas of the oral mucosa in close contact with amalgam restorations (CL; n = 142) or with OLR which involved other parts of the oral mucosa as well (OLP; n = 19). After examination, restorations of dental amalgam which were in contact with OLR in both patient groups were replaced. The effect of replacement was evaluated at a follow-up after 6-12 months. Results: In the CL group, the lesions showed a considerable improvement or had totally disappeared in 95% of the patients after replacement of the restorations of dental amalgam (n = 474). This effect was paralleled by a disappearance of symptoms, in contrast to patients with persisting CL (5%) who did not report any significant improvement. The healing response was not found to correlate with age, gender, smoking habits, subjective dryness of the mouth or current medication. However, the healing effect in patients who received gold crowns was superior compared to that of patients treated with metal-ceramic crowns (MC; P < 0.05). In the OLP group (n = 19), 63% of the patients with amalgam-associated erosive and atrophic lesions showed an improvement following selective replacement. OLP lesions in sites not in contact with amalgams were not affected. Most of the patients (53%) with OLP reported symptoms also after replacement. Conclusion: From these data it can be concluded that the vast majority of CL resolve following selective replacement of restorations of dental amalgam, provided that a correct clinical diagnosis is established. It is also noteworthy that MC crowns did not facilitate healing of CL to the same extent as gold crowns.