PURPOSE: To evaluate periodontal health after allogeneic haematopoietic cell transplantation (HCT), and its association with conditioning regimen intensity.

METHODS: This single-centre retrospective cohort study included 82 allogeneic HCT recipients between 01/08/2017 and 31/03/2022. Probing pocket depth (PPD), bleeding on probing (BOP), periodontal epithelial surface area (PESA) and periodontal inflamed surface area (PISA) were assessed pre- and post-HCT. Change scores were calculated, and regression models were applied to analyse associations with conditioning intensity. Conditioning regimens were categorised based on intensity as non-myeloablative (NMA), reduced intensity (RIC) or myeloablative (MA).

RESULTS: HCT recipients had a median age of 59 years (IQR 48-66); 63% were male. Median time to HCT was 53 days (IQR 29-89), median follow-up was 279 days (IQR 183-349). Severe periodontitis (≥ 1 site with PPD ≥ 6 mm) was observed in 37% of patients pre-HCT and 20% of patients post-HCT. PPD, BOP, PESA and PISA decreased from pre- to post-HCT, by 0.26 mm [95%CI 0.16;0.37], 8% [95%CI 5;12], 140 mm² [95%CI 89;190] and 123 mm² [95%CI 83;185], respectively. Prevalence of severe periodontitis decreased from pre- to post-HCT in all groups: NMA 50% to 27%, RIC 32% to 19%, MA 31% to 13%. Conditioning intensity was statistically significantly associated with post-HCT PPD and PESA; however, differences were small. No statistically significant differences were observed in post-HCT PISA between conditioning regimens.

CONCLUSION: Periodontal health improved marginally in the short-term following HCT and supportive oral care. Differences in post-HCT periodontal health between patients conditioned with NMA, RIC, and MA were not clinically relevant.