Riley Philip, Moore Deborah, Ahmed Farooq, Sharif Mohammad O, Worthington Helen V
Cochrane Oral Health Group, School of Dentistry, The University of Manchester, JR Moore Building, Oxford Road, Manchester, UK, M13 9PL.
Cochrane Database Syst Rev. 2015 Mar 26;2015(3):CD010743. doi: 10.1002/14651858.CD010743.pub2.
Dental caries is a highly prevalent chronic disease which affects the majority of people. It has been postulated that the consumption of xylitol could help to prevent caries. The evidence on the effects of xylitol products is not clear and therefore it is important to summarise the available evidence to determine its effectiveness and safety.
To assess the effects of different xylitol-containing products for the prevention of dental caries in children and adults.
We searched the following electronic databases: the Cochrane Oral Health Group Trials Register (to 14 August 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2014, Issue 7), MEDLINE via OVID (1946 to 14 August 2014), EMBASE via OVID (1980 to 14 August 2014), CINAHL via EBSCO (1980 to 14 August 2014), Web of Science Conference Proceedings (1990 to 14 August 2014), Proquest Dissertations and Theses (1861 to 14 August 2014). We searched the US National Institutes of Health Trials Register (http://clinicaltrials.gov) and the WHO Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.
We included randomised controlled trials assessing the effects of xylitol products on dental caries in children and adults.
Two review authors independently screened the results of the electronic searches, extracted data and assessed the risk of bias of the included studies. We attempted to contact study authors for missing data or clarification where feasible. For continuous outcomes, we used means and standard deviations to obtain the mean difference and 95% confidence interval (CI). We used the continuous data to calculate prevented fractions (PF) and 95% CIs to summarise the percentage reduction in caries. For dichotomous outcomes, we reported risk ratios (RR) and 95% CIs. As there were less than four studies included in the meta-analysis, we used a fixed-effect model. We planned to use a random-effects model in the event that there were four or more studies in a meta-analysis.
We included 10 studies that analysed a total of 5903 participants. One study was assessed as being at low risk of bias, two were assessed as being at unclear risk of bias, with the remaining seven being at high risk of bias.The main finding of the review was that, over 2.5 to 3 years of use, a fluoride toothpaste containing 10% xylitol may reduce caries by 13% when compared to a fluoride-only toothpaste (PF -0.13, 95% CI -0.18 to -0.08, 4216 children analysed, low-quality evidence).The remaining evidence on children, from small single studies with risk of bias issues and great uncertainty associated with the effect estimates, was insufficient to determine a benefit from xylitol products. One study reported that xylitol syrup (8 g per day) reduced caries by 58% (95% CI 33% to 83%, 94 infants analysed, low quality evidence) when compared to a low-dose xylitol syrup (2.67 g per day) consumed for 1 year.The following results had 95% CIs that were compatible with both a reduction and an increase in caries associated with xylitol: xylitol lozenges versus no treatment in children (very low quality body of evidence); xylitol sucking tablets versus no treatment in infants (very low quality body of evidence); xylitol tablets versus control (sorbitol) tablets in infants (very low quality body of evidence); xylitol wipes versus control wipes in infants (low quality body of evidence).There was only one study investigating the effects of xylitol lozenges, when compared to control lozenges, in adults (low quality body of evidence). The effect estimate had a 95% CI that was compatible with both a reduction and an increase in caries associated with xylitol.Four studies reported that there were no adverse effects from any of the interventions. Two studies reported similar rates of adverse effects between study arms. The remaining studies either mentioned adverse effects but did not report any usable data, or did not mention them at all. Adverse effects include sores in the mouth, cramps, bloating, constipation, flatulence, and loose stool or diarrhoea.
AUTHORS' CONCLUSIONS: We found some low quality evidence to suggest that fluoride toothpaste containing xylitol may be more effective than fluoride-only toothpaste for preventing caries in the permanent teeth of children, and that there are no associated adverse-effects from such toothpastes. The effect estimate should be interpreted with caution due to high risk of bias and the fact that it results from two studies that were carried out by the same authors in the same population. The remaining evidence we found is of low to very low quality and is insufficient to determine whether any other xylitol-containing products can prevent caries in infants, older children, or adults.
龋齿是一种非常普遍的慢性病，影响着大多数人。据推测，食用木糖醇有助于预防龋齿。关于木糖醇产品效果的证据尚不明确，因此总结现有证据以确定其有效性和安全性很重要。
评估不同含木糖醇产品对儿童和成人预防龋齿的效果。
我们检索了以下电子数据库：Cochrane口腔健康组试验注册库（截至2014年8月14日）、Cochrane对照试验中心注册库（CENTRAL）（《Cochrane图书馆》，2014年第7期）、通过OVID检索的MEDLINE（1946年至2014年8月14日）、通过OVID检索的EMBASE（1980年至2014年8月14日）、通过EBSCO检索的CINAHL（1980年至2014年8月14日）、科学网会议论文（1990年至2014年8月14日）、Proquest学位论文（1861年至2014年8月14日）。我们检索了美国国立卫生研究院试验注册库（http://clinicaltrials.gov）和世界卫生组织临床试验注册平台以查找正在进行的试验。检索电子数据库时对语言或出版日期没有限制。
我们纳入了评估木糖醇产品对儿童和成人龋齿影响的随机对照试验。
两位综述作者独立筛选电子检索结果、提取数据并评估纳入研究的偏倚风险。如有可能，我们试图联系研究作者获取缺失数据或进行澄清。对于连续性结果，我们使用均值和标准差来获得平均差和95%置信区间（CI）。我们使用连续性数据计算预防率（PF）和95%CI以总结龋齿减少的百分比。对于二分法结果，我们报告风险比（RR）和95%CI。由于纳入荟萃分析的研究少于四项，我们使用固定效应模型。如果荟萃分析中有四项或更多研究，我们计划使用随机效应模型。
我们纳入了10项研究，共分析了5903名参与者。一项研究被评估为低偏倚风险，两项被评估为偏倚风险不明确，其余七项为高偏倚风险。综述的主要发现是，在使用2.5至3年期间，与仅含氟牙膏相比，含10%木糖醇的含氟牙膏可能使龋齿减少13%（PF -0.13，95%CI -0.18至-0.08，分析了4216名儿童，低质量证据）。关于儿童的其余证据来自存在偏倚风险问题且效应估计存在很大不确定性的小型单项研究，不足以确定木糖醇产品的益处。一项研究报告称，与每天食用2.67克的低剂量木糖醇糖浆相比，木糖醇糖浆（每天8克）食用1年后龋齿减少58%（95%CI 33%至83%，分析了94名婴儿，低质量证据）。以下结果的95%CI与木糖醇相关的龋齿减少和增加均相符：儿童木糖醇含片与不治疗相比（证据质量极低）；婴儿木糖醇咀嚼片与不治疗相比（证据质量极低）；婴儿木糖醇片与对照（山梨醇）片相比（证据质量极低）；婴儿木糖醇擦拭巾与对照擦拭巾相比（证据质量低）。仅有一项研究调查了成人木糖醇含片与对照含片相比的效果（证据质量低）。效应估计的95%CI与木糖醇相关的龋齿减少和增加均相符。四项研究报告称任何干预措施均无不良反应。两项研究报告研究组之间的不良反应发生率相似。其余研究要么提及了不良反应但未报告任何可用数据，要么根本未提及。不良反应包括口腔溃疡、痉挛、腹胀、便秘、肠胃气胀以及腹泻或稀便。
我们发现一些低质量证据表明，含木糖醇的含氟牙膏在预防儿童恒牙龋齿方面可能比仅含氟牙膏更有效，且此类牙膏无相关不良反应。由于偏倚风险高且该效应估计来自同一作者在同一人群中进行的两项研究，因此对效应估计应谨慎解读。我们发现的其余证据质量低至极低，不足以确定任何其他含木糖醇产品是否能预防婴儿、大龄儿童或成人的龋齿。
