Study protocol for a randomized clinical trial to evaluate the effect of the use of Xylitol gum in the prevention of caries lesions in children living in Ladakh-the Caries Prevention Xylitol in Children (CaPreXCh) trial.

BACKGROUND: Xylitol use is reported to be able to reduce dental plaque amount and cariogenic bacteria and, as a consequence, the caries increment. Only few data on the oral health of Ladakh's population are available. The aim of the present protocol will be to record the caries prevalence of primary and permanent molars of schoolchildren living in Ladakh and to implement a school-based Xylitol programme, named the Caries Prevention Xylitol in Children (CaPreXCh) trial, using chewing gums. METHODS: The protocol is designed as a triple-blind randomized, controlled, parallel-group clinical trial in children aged 5-14 years. The study should have been carried out from August 2021 to August 2024 in Zanskar Valley (Ladakh), but the COVID-19 pandemic does not allow today to make predictions on the exact start. Participants will be randomly allocated into two groups: subjects who will receive a chewing gum with Xylitol (70% w/v) as only sweetener, and those who will receive a sugared chewing gum containing Maltitol (23% w/v). The subjects will be instructed to chew a total of 6 pellets for 5 min divided into 3 intakes a day (2 in the morning, 2 after the midday meal and 2 in the afternoon) for one school year. Clinical examination will comprise an oral examination in which caries index (ICDAS scores), bleeding on probing and plaque pH evaluation after sucrose challenge will be recorded at baseline (t0); the clinical examination will be repeated after 12 months since the beginning of the chewing gum administration period (t1), after another 12-month period (t2) and finally after further 12 months (t3) (24 months from the end of the chewing gum use). The primary outcome will be the caries increment measured both at enamel and dentinal levels on primary and permanent molars. Data analysis will be conducted through Kaplan-Meyer graphs to evaluate caries increment. A comparison of the methods will be carried out with Cox regression with shared frailty. The net caries increment for initial, moderate and severe caries levels, using ICDAS (Δ-initial, Δ-moderate and Δ-severe), will be calculated. DISCUSSION: This trial will be the first trial conducted in India assessing the efficacy of a school-based caries preventive programme through the use of chewing gum containing only Xylitol as a sweetener. The findings could help strengthen the evidence for the efficacy of Xylitol use in community-based caries prevention programmes in children. TRIAL REGISTRATION: Clinical trials.gov NCT04420780 . Registered on June 9, 2020.

Iota-carrageenan and xylitol inhibit SARS-CoV-2 in Vero cell culture.

Last year observed a global pandemic caused by SARS-CoV-2 (severe acute respiratory syndrome-coronavirus 2) infection affecting millions of individuals worldwide. There is an urgent unmet need to provide an easily producible and affordable medicine to prevent transmission and provide early treatment for this disease. Since the nasal cavity and the rhinopharynx are the sites of initial replication of SARS-CoV-2, a nasal spray may be an effective option to target SARS-CoV-2 infection. In this study, we tested the antiviral action of three candidate nasal spray formulations against SARS-CoV-2 in vitro. We determined that iota-carrageenan in concentrations as low as 6 µg/mL inhibits SARS-CoV-2 in vitro. The concentrations of iota-carrageenan with activity against SARS-CoV-2 in vitro may be easily achieved through the application of nasal sprays as commonly used in several countries. Recently a double-blind, placebo-controlled study showed that iota-carrageenan in isotonic sodium chloride reduces ca. five times the risk of infection by SARS-CoV-2 in health care personnel. Further, xylitol at a concentration of 50 mg/mL (ca. 329 mM) was found to exert some antiviral action, though this preliminary finding needs further confirmation.