Influence of the irradiation distance and the use of cooling to increase enamel-acid resistance with Er:YAG laser

Objectives

The aim of this study was to assess the influence of irradiation distance and the use of cooling in the Er:YAG laser efficacy in preventing enamel demineralization.

Methods

84 enamel blocks were randomly assigned to seven groups (n = 12): G1: control group – no treatment, G2–G7: experimental groups treated with Er:YAG laser (80 mJ/2 Hz) at different irradiation distances with or without cooling: G2: 4 mm/2 mL; G3: 4 mm/no cooling; G4: 8 mm/2 mL; G5: 8 mm/no cooling; G6: 16 mm/2 mL; G7: 16 mm/no cooling. The samples were submitted to an in vitro pH cycles for 14 days. Next, the specimens were sectioned in sections of 80–100 μm in thickness and the demineralization patterns of prepared slices were assessed using a polarized light microscope. Three samples from each group were analyzed with scanning electronic microscopy. Analysis of variance and the Fisher test were performed for the statistical analysis of the data obtained from the caries-lesion-depth measurements (CLDM) (alpha = 5%).

Results

The control group (CLDM = 0.67 mm) was statistically different from group 2 (CLDM = 0.42 mm), which presented a smaller lesion depth, and group 6 (0.91 mm), which presented a greater lesion depth. The results of groups 3 (CLDM = 0.74 mm), 4 (CLDM = 0.70 mm), 5 (CLDM = 0.67 mm) and 7 (CLDM = 0.89 mm) presented statistical similarity. The scanning electronic microscopy analysis showed ablation areas in the samples from groups 4, 5, 6 and 7, and a slightly demineralized area in group 2.

Conclusions

It was possible to conclude that Er:YAG laser was efficient in preventing enamel demineralization at a 4-mm irradiation distance using cooling.     

Detection of mutans streptococci in plaque samples from Mongolian preschool and school children

Mutans streptococci, in particular Streptococcus mutans and Streptococcus sobrinus, are generally considered to be the principal microbial pathogen of dental caries. The objective of the study was to isolate S. mutans and S. sobrinus, identify them by PCR, and to compare their presence with the caries status and caries risk in Mongolian preschool and school children. Forty one preschool children aged 3–5 years and 40 school children aged 12–15 years were enrolled in this study. As assessed using Cariostat test, 75.6% of preschool children had high caries risk and 37.5% of school children had high caries risk. In preschool children, the prevalence of S. mutans and S. sobrinus were 100% and 36.6%, respectively; 63.4% were positive for S. mutans alone and 36.6% were positive for both S. mutans and S. sobrinus. In school children, the prevalence of S. mutans and S. sobrinus were 100% and 25.0%, respectively; 75.0% carried S. mutans alone and 25.0% had both S. mutans and S. sobrinus. The percentage of children positive for both S. mutans and S. sobrinus in the high caries risk group were significantly higher than those in the low risk group of either preschool (42.0% vs. 10.0%, P< 0.001) or school children (46.6% vs. 12.0%, P<0.001). Moreover, the caries status of children positive for both S. mutans and S. sobrinus were significantly higher than those positive for S. mutans alone (P< 0.01 for preschool children, and P< 0.05 for school children).     

广州市5岁儿童乳牙龋病相关因素分析

目的调查5岁儿童乳牙患龋情况及相关影响因素,为儿童龋病预防提供资料。方法采用多阶段、分层、等容量、随机抽样的方法抽取720名5岁儿童进行乳牙龋病检查,同时对其家长进行现场问卷调查。对调查结果先采用卡方检验行单因素分析,再行多因素非条件Logistic回归分析。结果乳牙患龋率和龋均分别为57.50%、2.90,男女间差异无统计学意义（P〉0.05）。单因素分析表明家庭的孩子数、儿童进食甜食的习惯、儿童开始刷牙的年龄、每天刷牙的次数、父母是否检查孩子的刷牙效果、对含氟牙膏的知晓率、对孩子口腔健康的评价、家长的学历等相关因素都对乳牙患龋有明显影响。多因素非条件Logistic回归分析表明儿童进食糖水的频率、家长对口腔健康的评价、家长的学历是儿童乳牙患龋的危险因素。结论儿童家长应提高对口腔健康知识的知晓率,主动采取利于口腔健康的行为,以帮助儿童建立健康的口腔行为。     

Essential health care package for children ‐ the ‘Fit for School’ program in the Philippines

High prevalence of poverty diseases such as diarrhoea, respiratory tract infection, parasitic infections and dental caries among children in the developing world calls for a return to primary health care principles with a focus on prevention. The ‘Fit for School’ program in the Philippines is based on international recommendations and offers a feasible, low‐cost and realistic strategy using the principles of health promotion outlined in the Ottawa Charter. The cornerstone of the programme is the use of school structures for the implementation of preventive health strategies. ‘Fit for School’ consists of simple, evidence‐based interventions like hand washing with soap, tooth brushing with fluoride toothpaste and other high impact interventions such as bi‐annual de‐worming as a routine school activity for all children visiting public elementary schools. The programme has been successfully rolled‐out in the Philippines covering 630,000 children in 22 provinces and it is planned to reach 6 million children in the next three years. The programme is a partnership project between the Philippine Department of Education and the Local Government Units with support for capacity development activities from the German Development Cooperation and GlaxoSmithKline.     

幼儿期唾液中变形链球菌数与患龋状况关系的研究——同所幼儿园5年追踪观察

目的：探讨幼儿期唾液中S.mutans菌数情况,分析其与乳牙患龋状况的关系。方法：以同所幼儿园3～5岁幼儿（累计854名）为对象,连续5年作乳牙龋病检查,用Dentocult SM作唾液中S.mutans菌数检测,统计分析Dentocult SM各度的患龋状况及两者间的相关关系。结果：5年间854名幼儿患龋率为58.90%,dft为3.00±3.70,CSI为10.05±13.99,男女性别间无差异,患龋状况在各年间无差异,854名幼儿Dentocult SM0度之人数占36.8%,1度占24.5%,2度占27.9%,3度占10.9%。Dentocult SM各度间患龋率、dft、CSI均有明显差异。Dentocult SM分度与dft、CSI之相关性有统计学意义。DentocultSM检测法一致度74.63%,敏感度79.02%。结论：幼儿患龋状况仍很严峻,幼儿期唾液中S.mutans菌数与患龋状况有相关性,DentocnltSM是一种简便而有效的龋病活跃性检测方法。     

窝沟封闭材料防治老年根面龋的临床观察

目的：考察窝沟封闭材料防治老年根面龋的临床效果。方法：选用3Mclinpro变色窝沟封闭剂作实验材料.复合树脂作对照,对60岁以上临床诊断有活动性根面龋的老年患者进行封闭治疗。结果：1年封闭剂涂膜保留率为79％,复合树脂的保留率为64.44％,两者相比差异有统计学意义,P〈0.05。结论：3Mclinpro变色窝沟封闭剂,防治老年根面龋的效果良好。     

Caries infiltrant combined with conventional adhesives for sealing sound enamel in vitro

Objective:To test the null hypothesis that combining low-viscosity caries infiltrant with conventional adhesive resins would not improve sealing of sound enamel against demineralization in vitro.Materials and Methods:Bovine enamel discs (N  =  60) with diameter of 3 mm were randomly assigned to six groups (n  =  10). The discs were etched with 37% phosphoric acid for 30 seconds and treated with resins of different monomer content forming the following groups: (1) Icon (DMG), (2) Transbond XT Primer (3M ESPE), (3) Heliobond (Ivoclar Vivadent), (4) Icon + Transbond XT Primer, and (5) Icon + Heliobond. Untreated etched samples served as the negative control. Specimens were subjected to demineralization by immersion in hydrochloric acid (pH 2.6) for 80 hours. Calcium dissolution into the acid was assessed by colorimetric analysis using Arsenazo III method at 16-hour intervals. Groups presenting high protection against demineralization were subjected to further acidic challenge for 15 days with calcium measurements repeated at 24-hour intervals. Data were analyzed by Kruskal-Wallis test and Mann-Whitney U-test.Results:Untreated specimens showed the highest amount of demineralization. Icon and Transbond XT primer decreased the mineral loss significantly compared to the control. Heliobond performed significantly better than both Icon and Transbond XT primer. Combination of Icon both with Transbond XT primer or Heliobond served as the best protective measures and maintained the protective effect for the additional 15-day acidic challenge.Conclusions:Within the limitations of this in vitro study, it could be concluded that the use of low-viscosity caries infiltrant prior to application of the tested conventional adhesives increases their protective effect against demineralization.     

广东南海两镇人群龋病抽样调查报告

目的 了解南海市南庄镇和小塘镇人群龋病流行病学状况，作为制订防龋计划的依据和防龋项目评价的基线资料。方法 按照第二次全国口腔健康流行病学调查标准，对两镇３～７４岁人群进行龋病流行病学抽样调查。结果 ５岁组乳牙龋均为３．５８５（南庄）和５．２３９（小塘）；１０岁组恒牙龋均为１．１９６（南庄）和１．４３８（小塘）；在年龄较大的人群两镇患龋情况差别不大，在青少年中患龋情况小塘镇高于南庄镇。结论 ①南海市小塘镇和南庄镇人群龋病情况均符合全身用氟项目的试点研究的条件；②两镇龋病状况处于低等级水平，与广东省患龋水平接近，高于全国平均水平；③两镇患龋情况在青少年中小塘镇稍高于南庄镇。     

Accidental ingestion of foreign object: Systematic review,recommendations and report of a case

One of the serious complications during a routine endodontic procedure is accidental ingestion/aspiration of the endodontic instruments, which can happen when proper isolation is not done. There are at present no clear guidelines whether foreign body ingestion in the gastrointestinal tract should be managed conservatively, endoscopically or surgically. A 5 year old boy reported to the Department of Pediatric and Preventive Dentistry, D.A. Pandu Memorial R.V. Dental College, Bangalore, India, with a complaint of pain and swelling in the lower right back teeth region. Endodontic therapy was planned for the affected tooth. During the course of treatment the child accidentally swallowed a 21 mm 15 size K file. Endoscopy was performed immediately but the instrument could not be retrieved. The instrument passed out uneventfully along with the stools 48 h after ingestion.Careful evaluation of the patient immediately after the accident helps in managing the patient effectively along with following the recommended guidelines.     

食物在龋病四联因素中作用的研究

本文对119例龋病的初发部位与年龄的关系及78例成人第二磨牙龋病的初发部位与第三磨牙生长位置关系进行了研究，结果显示：四联因素（即：细菌、食物、时间和宿主）在龋病的形成过程中并非等列。食物在四种因素中可能起着主导作用。提示：在龋病的预防中，如果重视解决食物嵌塞问题，其效果可能较其它方法会更好。