Twetman S, Frostner N
Department of Pedodontics, Länssjukhuset, Halmstad, Sweden.
Swed Dent J. 1991;15(3):145-51.
The aim of this study was to obtain cross-sectional information about the quantitative distribution of salivary mutants streptococci assessed with a clinically applicable microbiological method and the relation to dental caries in young schoolchildren. A total of 355 8-year-old children were examined for the presence and number of mutants streptococci in saliva by a specially prepared strip, the "Strip-mutans" method, cultivated in a selective broth. The strips were first visually examined and grouped by aid of a templet provided by the manufacturer and thereafter transferred to a laboratory for enumeration of colony forming units (CFU) with aid of a stereomicroscope. Caries scores were obtained from the dental records. Mutans streptococci were identified in 70% of all children. 46% were free from the bacterium or harboured low levels (0-10 CFU) while high levels (greater than or equal to 500 CFU) were found only in 6% of the material. Strong positive correlations (p less than 0.001) were found between different levels of mutans streptococci infection and the caries experience in both the primary (dmfs) and the permanent (DMFS) dentition. A statistically significant correlation between the direct examination and the microscopic enumeration was disclosed (r = 0.84). The bacterial culturing technique used in this study proved to be practical and reliable and thus useful in clinical routines of pediatric dentistry.
本研究的目的是通过一种临床适用的微生物学方法，获取有关儿童唾液中变形链球菌定量分布的横断面信息，以及其与年轻学童龋齿的关系。通过特制的试纸条（“变形链球菌试纸条”法）在选择性肉汤中培养，对355名8岁儿童的唾液进行了变形链球菌的存在情况及数量检测。首先对试纸条进行目视检查，并借助制造商提供的模板进行分组，然后将其转移至实验室，借助体视显微镜对菌落形成单位（CFU）进行计数。龋齿评分来自牙科记录。在所有儿童中，70%检测到变形链球菌。46%的儿童未感染该细菌或携带低水平（0 - 10 CFU）的变形链球菌，而高水平（大于或等于500 CFU）仅在6%的样本中发现。在原发性（dmfs）和恒牙列（DMFS）中，不同水平的变形链球菌感染与龋齿经历之间均发现了强正相关（p < 0.001）。直接检查与显微镜计数之间存在统计学显著相关性（r = 0.84）。本研究中使用的细菌培养技术被证明是实用且可靠的，因此在儿童牙科临床常规中很有用。
