Pilocarpine alters caries development in partially-desalivated rats

The effect of pilocarpine on dental caries in patients with primary Sjögren's syndrome: a database prospective cohort study

Background

Primary Sjögren’s syndrome (pSS) is associated with dental caries. Pilocarpine, a salivary stimulant, can improve the amount and flow rate of saliva in patients with pSS. This study aimed to assess whether the risk of dental caries decreases with the use of pilocarpine in patients with pSS.

Methods

For this prospective cohort study, we identified pSS patients from the catastrophic illnesses registry of the National Health Insurance Research Database of Taiwan between 2009 and 2013. We divided participants into pilocarpine and non-user groups based on the pilocarpine prescriptions available during the first 3-month follow-up. The primary endpoint was dental caries. The secondary endpoints were periodontitis and oral candidiasis. We compared the risk of these oral manifestations using the Cox proportional hazard model.

Results

A total of 4973 patients with new-onset pSS were eligible for analysis. After propensity score matching, we included 1014 patients in the pilocarpine group and 2028 patients in the non-user group. During the mean follow-up of 2.6 years, the number of events was 487 in the pilocarpine group (48.0%) and 1047 in the non-user group (51.6%); however, the difference was not significant (hazard ratio [HR] 0.93, 95% confidence interval [CI] 0.82 to 1.06). Furthermore, there was no significant difference between groups regarding risk of periodontitis (HR 0.91, 95% CI 0.81 to 1.03) and oral candidiasis (HR 1.16, 95% CI 0.70 to 1.94).

Conclusion

Pilocarpine may have no protective effect on dental caries, periodontitis, or oral candidiasis in patients with pSS.

Susceptibility of partially desalivated rats to erosive tooth wear by calcium-supplemented beverages

OBJECTIVES

To investigate the susceptibility of partially desalivated rats to erosive tooth wear (ETW); the anti-erosive effect of a calcium-supplemented beverage; and the quantification of ETW by microcomputed tomography (micro-CT).

METHODS

The study population consisted of thirty-eight rats, divided into partially desalivated (n = 19) and normal salivary flow (n = 19). They were randomly allocated into three subgroups (n = 6-7): A-diet soda, B-diet soda + calcium, C-water (control). Solutions were provided ad libitum for 28 days, and the rats were euthanized afterwards. Each left hemi-mandible was scanned using micro-CT for enamel volume (three molars) calculation. Visual analysis of photographs of the lingual surface of first molars was performed independently by three blinded examiners. Data were statistically analysed (α = .05).

RESULTS

Micro-CT revealed no significant differences between partially desalivated or normal groups. Rats consuming A had more enamel loss than those consuming B or C, which did not differ from each other. For visual analysis, desalivation did not affect ETW. Rats consuming C showed the lowest ETW, followed by B and then A, for both partially desalivated and normal rats. Spearman correlation between the two ETW quantification methods was -.65.

CONCLUSIONS

Partial desalivation did not increase ETW. Ca-containing beverage prevented ETW. Micro-CT quantified ETW, although it was not as sensitive as visual analysis.

Sjogren's syndrome: Clinical aspects

Sjogren's syndrome (SS) is the 2nd most common chronic autoimmune rheumatic disease and associated with a high burden of illness. Morbidity arises not only from untreated xerostomia and keratoconjunctivitis sicca but also from extra-glandular manifestations including the development of non-Hodgkin's B cell lymphomas. Proper diagnosis of SS requires objective evidence of dry eyes and/or objective evidence of dry mouth as well as proof of autoimmunity. The recent development of new international classification criteria and clinical practice guidelines for SS should not only enhance the existing standards of care but also facilitate further studies to improve future diagnosis and outcomes.

Efficacy and economic evaluation of pilocarpine in treating radiation-induced xerostomia

Xerostomia, resulting from therapeutic irradiation of the head and neck, can be debilitating and destructively impact the patient's quality of life. The first priority of treatment of radiation-induced xerostomia should be to preserve oral and dental health. Therapeutic doses of fluoride and meticulous dental hygiene are the treatments of choice for this purpose. Measures taken to prevent superinfection with cariogenic bacteria and fungi are also important. In addition to minimising damage to the dentition, it is important to provide palliative therapy to help the patient live a more normal life. Salivary substitutes help some patients but muscarinic, cholinergic sialogogues provide a more physiological replacement in those patients who have measurable residual salivary function. An oral formulation of pilocarpine hydrochloride is approved to treat radiation-induced xerostomia. In such cases, it has been shown to effectively stimulate salivary flow and relieve subjective symptoms associated with oral dryness. Administration of this drug is associated with predictable, but generally tolerable, adverse effects. Similar drugs, approved for other indications, have been shown to produce comparable results. These drugs are generally less expensive than the oral formulation of pilocarpine. As treatment of irradiation-induced xerostomia with muscarinic, cholinergic sialogogues is palliative, not curative, administration of these drugs should be individualised and guided by the patient's willingness to balance symptomatic efficacy with adverse effects and the expense of treatment.

Effect of pilocarpine mouthwash on salivary flow

Pilocarpine is a cholinergic agonist that increases salivary flow and has been used to treat xerostomia. Oral intake is the most frequent route of administration. Adverse effects are dose-dependent and include sudoresis, facial blushing and increased urinary frequency. The objective of the present study was to evaluate the effects of topical pilocarpine solutions as mouthwashes on salivary flow and their adverse effects on healthy subjects. Forty volunteers received 10 ml 0.5, 1 and 2% pilocarpine solutions or 0.9% saline in a randomized, double-blind, placebo-controlled manner. Salivation was measured before and 45, 60 and 75 min after mouth rinsing for 1 min with 10 ml of saline or pilocarpine solutions. Vital signs were measured and ocular, gastrointestinal and cardiovascular symptoms, anxiety and flushing were estimated using visual analog scales. There was a dose-dependent increase in salivation. Salivation measured after 1 and 2% pilocarpine (1.4 +/- 0.36 and 2.22 +/- 0.42 g, respectively) was significantly (P<0.001) higher than before (0.70 +/- 0.15 and 0.64 +/- 0.1 g), with a plateau between 45 and 75 min. Cardiovascular, visual, gastrointestinal and behavioral symptoms and signs were not changed by topical pilocarpine. Mouth rinsing with pilocarpine solutions at concentrations of 1 to 2% induced a significant objective and subjective dose-dependent increase in salivary flow, similar to the results reported by others studying the effect of oral 5 mg pilocarpine. The present study revealed the efficacy of pilocarpine mouthwash solutions in increasing salivary flow in healthy volunteers, with no adverse effects. Additional studies on patients with xerostomia are needed.

The treatment of Sjögren's syndrome patients with pilocarpine-tablets

Therapeutic progress in Sjögren's syndrome has lagged behind our recognition and understanding of clinical manifestations and disease pathogenesis. Past treatment of sicca symptoms with immunosuppressives has been unsuccessful. The use of secretagogues (e.g. pilocarpine-HCl) to stimulate flow from exocrine glands represents a novel approach that has dramatically altered our management strategy for Sjögren's syndrome. Clinical studies with pilocarpine (Salagen) tablets in the United States have demonstrated significant subjective and objective benefit for xerostomia and related oral symptoms at doses of 20 mg/day or more. Symptomatic relief of xerophthalmia and other xeroses due to Sjögren's syndrome may also occur. Data from human and animal models suggest that regular use of pilocarpine may not only improve patient quality of life but potentially prevent complications as well. Better methods of patient selection for therapy are needed since clinical response to pilocarpine cannot be predicted based on the duration of patient symptoms.

High-resolution electrophoretic analysis of rat parotid salivary proteins

Silver staining and high-resolution electrophoretic methods have been used to compare the protein composition of rat parotid saliva evoked in response to (i) parasympathetic stimulation (including the nonadrenergic, noncholinergic, atropine-associated secretion), (ii) sympathetic stimulation, or (iii) the infusion of neuropeptides with secretagogue activity (substance P, calcitonin gene-related peptide, neuropeptide Y, or vasoactive intestinal peptide). The different stimuli influenced the protein concentration and flow rate of the evoked secretion but had little effect upon the protein composition of the saliva. In contrast to earlier studies using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Coomassie blue staining, the combination of silver staining and two-dimensional electrophoresis (2-DE) revealed many newly detected proteins. The results indicate that the protein composition of rat parotid saliva is more complex than previously reported but is unaffected by the mode of stimulation.