Effect of selected beta-blockers on supragingival calculus formation

Supragingival plaque and calculus indices, salivary flow rates, pH, ionic and total calcium concentrations, total phosphate concentration, and the number of cervical restorations and caries lesions were measured in 29 subjects using systemic beta-(beta) blockers and in 28 subjects who were not taking any systemic medication. After 8 weeks of normal oral hygiene following an oral prophylaxis, a second comparison of each of the above quantities was made. With the exception of the calculus indices and the incidence of cervical restorations, no significant differences were found for any of the measured quantities between the medicated and non-medicated groups at either examination. The medicated group showed significantly lower mean calculus values than the non-medicated group at both examinations and a higher incidence of cervical restorations at the baseline examination, suggesting that beta-blockers decrease the rate of mineralization in the oral cavity. Since beta-blockers did not appear to alter stimulated salivary pH, flow rate, phosphate, ionic calcium or total calcium concentrations, their effect on the mineralization processes must be attributed to other mechanisms. Two hypotheses appear plausible: changes in salivary mineralization rates caused by either direct physico-chemical effects of the secreted beta-blockers in the saliva, or by alterations in the salivary protein/glycoprotein composition, enzymes and oral bacterial flora owing to systemic pharmacological effects of beta-blockers.