# The effect of conditioning regimen intensity on periodontal health in haematopoietic cell transplantation recipients: a 5-year multicentre prospective cohort study

## TL;DR

This study found that the intensity of conditioning regimens before transplants does not significantly affect periodontal health over five years.

## Contribution

The study provides new long-term evidence on the lack of association between conditioning intensity and periodontal outcomes in transplant recipients.

## Key findings

- Conditioning intensity was not significantly associated with changes in probing pocket depth, bleeding on probing, or gingival recession over five years.
- Periodontal changes observed were small and not clinically significant, with some parameters returning to baseline levels by five years post-transplant.

## Abstract

To evaluate periodontal health and its association with conditioning intensity over five years post-HCT.

This multicentre prospective study included 104 patients from two Dutch centres. Probing pocket depth (PPD), bleeding on probing (BOP), and buccal gingival recession (GR) were assessed pre-HCT and at three (n = 34), six (n = 45), twelve (n = 46), eighteen months (n = 30), and five years (n = 36) post-HCT. Regression models evaluated associations with conditioning intensity and time since HCT.

HCT recipients had a median age of 58 years; 56% were male, and 59% received an allogeneic transplant. At baseline, mean PPD was 2.3 mm (31% had PPD ≥ 6 mm), mean BOP was 23%, and the median number of teeth with GR ≥ 1 mm was nine. Conditioning intensity was not significantly associated with PPD, GR, or BOP over time. Mean PPD decreased slightly at twelve months post-HCT (-0.21 mm (95%CI -0.28, -0.14)) but increased marginally at five years (0.12 mm (95%CI 0.08, 0.16)) compared to baseline. GR increased gradually with 0.13 mm (95%CI 0.07, 0.19) at twelve months, and 0.16 mm (95%CI 0.10, 0.23) at five years. BOP declined at twelve months (-11% (95%CI -15, -8)) but returned to baseline at five years (-1% (95%CI -5, 4)).

Our results suggest that conditioning intensity does not affect long-term periodontal health. Periodontal changes up to five years post-HCT were small.

Conditioning intensity may not be a key determinant of post-HCT periodontal health. Post-HCT periodontal deterioration was not found in our study.

The online version contains supplementary material available at 10.1007/s00784-025-06393-3.