Effect of improved periodontal health in renal recipients

Sir,

Dental and periodontal infections are considered risk factors for chronic kidney disease and can affect the successful outcome of renal transplantation. This prospective cohort study was undertaken to assess the effect of improved oral and periodontal status by nonsurgical periodontal therapy (NSPT) prior to renal transplantation in renal recipients. This study comprised 30 patients, posted for renal transplantation. They received NSPT prior to transplantation and were under triple drug therapy (tacrolimus,mycophenolate and corticosteroid). Systemic parameters (serum creatinine, serum albumin, IgM cytomegalovirus [CMV]), periodontal parameters (modified gingival index, plaque index, oral hygiene index, probing pocket depth [PPD], clinical attachment level [CAL]), gingival and oral mucosal changes before and six months after transplantation were assessed. Improved oral hygiene status was observed at re-evaluation. All periodontal parameters, except PPD and CAL showed significant improvement six months after renal transplantation whereas PPD (0.2 mm) and CAL (0.21 mm) increased significantly. IgM CMV was negative at baseline and six months after transplantation. Only 16.6% of the patients presented with gingival overgrowth and 13.3% with oral mucosal lesions six months after renal transplantation [Table 1].

Table 1 Comparison of oral and periodontal parameters at baseline and re-evaluation

In this study, even though our patients were maintaining a good oral hygiene after periodontal therapy, PPD, CAL and gingival recession (GR) appeared to be increased six months after renal replacement therapy. Glucocorticoid is known to inhibit bone remodelling and stimulate osteoclast-mediated bone resorption.[1] So this increase in the PPD and CAL may be the effect of systemic administration of corticosteroids. Consistent with our study, Oshrain et al.[2] reported that the mean periodontal disease index and gingival index of the healthy individuals were lower than those of patients on dialysis and transplant recipients. Low incidence of gingival overgrowth and the mucosal lesion observed in our study group may be due to the effect of tacrolimus, nonsurgical periodontal treatment and maintenance of good oral hygiene. Renal transplant patients affected with periodontitis might be at risk of viral amplification within the periodontal pocket despite antiviral therapy.[3] Nonsurgical periodontal treatment and antiviral therapy decrease the chance of replication of virus.[4]

The mean difference in the pocket depth (0.2 mm) observed in this study cannot be ignored, because recolonization of pathogens can occur in the periodontal pocket within 60 days of scaling and root planning. Gram-negative anaerobic bacteria in the periodontal pocket can serve as a large reservoir and may act as foci for infections. Thus periodontal pathogen can potentiate bacteremia/viremia in immunosuppressed patients that may affect the survival of the transplant. Re-evaluation and maintenance phase of periodontal therapy may effectively reduce the number of pathogens colonized in the sub gingival biofilm and thereby reduce systemic dissemination. Maintenance phase of periodontal therapy is mandatory because recolonization of pathogens can occur in the periodontal pocket. In order to eliminate such covert source of inflammation and better graft survival, periodontal therapy should become a part of institutional protocol for renal transplantation.