Comparison of Powered versus Manual Tooth Brushing for Safety and Efficacy in Patients with Gingivitis: A Randomised, Multicentre Clinical Trial in China.

OBJECTIVE: To evaluate the effects of powered and manual tooth brushing on gingival inflammation in a Chinese population with mild to moderate gingivitis. METHODS: The present randomised, single-blind, parallel clinical trial was conducted in five cities in China. Generally healthy participants aged 18 to 65 years, who were non-smokers and had at least 20 sites of gingival bleeding, were included as eligible subjects. The subjects were randomly assigned to either the powered tooth brushing (PTB) group or standard manual tooth brushing (MTB) group. All subjects were supplied with a fluoride-containing toothpaste, Gingival Bleeding Index (GBI), Modified Gingival Index (MGI) and the Turesky modification of the Quigley-Hein Plaque Index (MPI) were used to evaluate the outcomes. RESULTS: A total of 235 subjects completed the study, 118 in the PTB group and 117 in the MTB group. The mean age and sex distribution for the PTB and MTB groups were 34.40 ± 9.99 years, 89 women and 29 men, and 34.20 ± 10.14 years, 82 women and 35 men, respectively. After 6 months, the percentage decrease in MGI was 26.150% ± 26.897% for the PTB group and 14.768% ± 38.544% for the MTB group (P = 0.0092). Statistically significant differences between types of tooth brushing were also observed at 6 months for GBI, and at all time points for MPI. CONCLUSION: Tooth brushing with a powered toothbrush twice a day was shown to be more effective than use of a manual toothbrush in reducing gingival inflammation, gingival bleeding and surface plaque after a 6-month period. Both kinds of toothbrushes were safe for the oral tissues.

Trend on dental caries status and its risk indicators in children aged 12 years in China: a multilevel analysis based on the repeated national cross-sectional surveys in 2005 and 2015.

BACKGROUND: This study aimed to explore the trend and risk indicators for dental caries of children aged 12 years in China based on national oral health survey data in 2005 and 2015. METHODS: Research data were from the two latest national oral health surveys conducted in mainland China, including 30 and 31 provinces, autonomous regions, and municipalities in 2005 and 2015, respectively. Children aged 12 years were clinically examined for dental caries and dental fluorosis according to the World Health Organization criteria. Sociodemographic characteristics and oral health-related behaviours were collected using questionnaires. Multilevel zero-inflated negative binomial regression model was used to investigate the association between dental caries severity and dental fluorosis, sociodemographic characteristics, and oral health-related behaviours. RESULTS: The final analyses included 12,350 and 27,818 children surveyed in 2005 and 2015, respectively. The standardized prevalence of dental caries increased from 27.05% (95% confidence interval [CI], 24.25-28.85) in 2005 to 37.92% (95% CI, 34.94-40.90) in 2015, and the respective standardized mean decayed, missing, filled teeth (DMFT) index scores increased from 0.50 (standard deviation [SD], 1.04) to 0.83 (SD, 1.45) (P < 0.001). Fujian province had the highest increase in dental caries, followed by Liaoning, Heilongjiang, Hainan, and Yunnan. Results revealed that children who were girls, more frequently experienced dental pain, and had more recent dental visits, had significantly higher DMFT scores after adjusting for the survey year and other variables (all P < 0.05). CONCLUSIONS: Dental caries of 12-year-old children in China deteriorated from 2005 to 2015, particularly in the northeast and southwest regions. Dental caries was associated with sex, dental pain, and dental service utilization.

Prevalence and Associated Factors of Tooth Wear in Shanghai.

OBJECTIVE: To estimate the prevalence and distribution of tooth wear among groups of adolescents and adults in Shanghai, China through an epidemiological survey, and explore the associated factors. METHODS: Multistage, stratified, constant volume and cluster sampling methods were used in an epidemiological survey conducted in Shanghai in 2014. The basic erosive wear examination (BEWE) index was used to screen for tooth wear in different age groups: 12 years, 15 years, 18 to 35 years, 36 to 49 years and 50 to 74 years. A previously published questionnaire collected information including dietary habits, oral hygiene habits and general conditions. RESULTS: This survey reports the results for 1806 participants in Shanghai. The prevalence of tooth wear was 59.7% in adolescents (BEWE ≥ 1) and 93.1% in adults (BEWE ≥ 2). The prevalence and severity of disease increased with age (P < 0.01). The teeth most susceptible to wear were the central incisors and first molars. Multivariate analysis of covariance (ANCOVA) results showed that soft drinks, alcoholic drinks, pickled vegetables and hard food, gastroesophageal reflux disease (GERD), xerostomia and poor tooth brushing habits were statistically correlated with tooth wear in different age groups. CONCLUSION: The prevalence of tooth wear appears to be high in adolescents and adults in Shanghai. Frequent consumption of soft or alcoholic drinks, GERD, xerostomia and poor tooth brushing habits were positively associated with tooth wear in different age groups.

Relationship between periodontal disease and male infertility: A case-control study.

OBJECTIVES: To compare the prevalence of chronic periodontitis between men who had semen abnormalities and those who had normozoospermia through a case-control study. MATERIALS AND METHODS: Male patients who visited the assisted reproduction clinic of a large general hospital and were diagnosed with semen abnormalities were included in the case group. The control group was composed of patients of the same clinic with normozoospermia. The semen analysis included sperm concentration, count and progressive and total motility, which were measured in the laboratory. A questionnaire and clinical periodontal examination were conducted for all participants. Logistic regression was performed to explore the relationship between chronic periodontitis and male infertility. RESULTS: A total of 192 participants were included: 63 participants (32.8%) had some type of semen abnormality (case group), while 129 participants (67.2%) had normozoospermia (control group). The case group had a significantly higher prevalence of moderate/severe periodontitis than the control group (33.3% vs. 17.8%, p = .012). The logistic regression showed that participants who had moderate/severe periodontitis had a greater chance of having semen abnormalities after adjusting for other confounding factors (OR = 3.377, p = .005). CONCLUSIONS: Periodontitis is associated with semen abnormalities and sperm motility in men.

The 4th National Oral Health Survey in the Mainland of China: Background and Methodology.

Oral disease patterns change over time and it is important to conduct epidemiological surveillance population surveys regularly to monitor the situation. The overall objectives of the present survey were: (1) to describe the oral health status of Chinese children and adults in the 2015-2016 4th National Oral Health Survey; (2) to investigate the oral health knowledge, attitudes, and behaviours among children and adults; (3) to explore the association among sociodemographic characteristics, oral health behaviours, and the oral health status of Chinese children and adults. A national oral health survey was conducted among a representative sample of Chinese children and adults. Local residents from the five age groups - 3 to 5 years, 12 to 15 years, 35 to 44 years, 55 to 64 years, and 65 to 74 years - were selected. A multi-stage cluster sampling method was adopted for the identification of participants. All 31 provinces, autonomous regions and municipalities of the mainland of China were included. All participants were clinically examined and information on their oral health status, including oral mucosal lesions, dental caries experience, periodontal health status, dental fluorosis, and dental prosthesis status, was collected according to the procedures and criteria recommended by the World Health Organization (WHO). A calibration training programme and quality control procedures were conducted to ensure the reliability of the findings. Information on sociodemographic background, oral health behaviours, knowledge and attitude was also collected from all five age groups through a questionnaire survey.

[A survey on knowledge, attitude and practice related to evidence-based dentistry among dental students].

PURPOSE: To investigate the knowledge, attitude and practice related to evidence-based dentistry among dental students, and to provide a reference for targeted evidence-based dentistry teaching and practice evidence-based dentistry in dental students. METHODS: Dental students who attended the internship in Shanghai Ninth People's Hospital and Pudong People's Hospital were invited to attend this survey. Information on knowledge, attitude and practices related evidence-based dentistry was collected through questionnaires. SPSS 21.0 software package was used for data analysis. RESULTS: A total of 62 dental students attended this survey. Evidence-based dentistry related knowledge and attitude scores were 5.5±1.9 and 5.1±1.0, respectively. Over three quarters of students took courses on evidence-based medicine, while around half of students (56.5%) self-reported that they knew little about evidence-based medicine. 70.5% students practiced evidence-based dentistry less than once in the process of clinical decision making per week. The majority of students (80.3%) used MEDLINE or other databases to search for practice-related literature less than once per week. 63.9% students used practice guideline. The top three barriers to practice evidence-based dentistry were lack of information resources, insufficient time and lack of search skills. CONCLUSIONS: Evidence-based dentistry related knowledge and practice among dental students is deficient, whereas they hold positive attitude on practice. The top three barriers to practice evidence-based dentistry are lack of information resources, insufficient time and lack of search skills.

[Clinical study on the effect of anti-gingivitis IgY toothpaste in control of gingivitis and dental plaque].

PURPOSE: To observe the effect of anti-gingivitis IgY toothpaste in control of gingivitis and plaque. METHODS: The study was a double-blind, randomized, parallel-controlled clinical trail with a total of 100 subjects who were divided into two groups, experimental group and control group. The subjects in experimental group used anti-gingivitis IgY toothpaste to brush twice daily for 3 minutes, and the subjects in control group used none anti-gingivitis IgY toothpaste. The examiner recorded GI, PI and BOP index of all subjects at the baseline, 6-weeks and 12-weeks. SPSS21.0 software package was used for statistical analysis. RESULTS: Twelve weeks later, there were significant differences in GI and BOP between the two groups. Yet no significant difference was found in PI. CONCLUSIONS: Anti-gingivitis IgY toothpaste is effective in control of gingivitis.

[Preparation and identification of polyclonal antibody of Streptococcus salivarius 57.I urease].

PURPOSE: To prepare and identify polyclonal antibody of Streptococcus salivarius 57.I urease. METHODS: The biggest structural subunit of Streptococcus salivarius 57.I urease, UreC, was obtained by gene clone, IPTG-induced expression, and purification through affinity chromatography. Anti-sera and polyclonal antibody were raised by immunizing rabbits with purified UreC. Western blot was utilized to detect the specific combination of polyclonal antibody with UreC. RESULTS: Purified UreC protein was prepared and used as antigen to immunize rabbits. Polyclonal antibody was obtained， and Western blot displayed a specific band of the polyclonal antibody with UreC about 62 kD as anticipated. CONCLUSIONS: Polyclonal antibody against Streptococcus salivarius 57.I urease is obtained, which provides an important tool to explore the function of urease and its relationship with dental caries.

Dental erosion among children aged 3-6 years and its associated indicators.

OBJECTIVES: To analyze the status quo of dental erosion in 3- to 6-year-old children in Shanghai. METHODS: A stratified, cluster, multistage random sampling methods was applied to 3- to 6-year-old children in Shanghai in 2012. Both questionnaire and clinical oral examination were performed in the survey. The questionnaire included general information, such as age, gender, parental education, dietary habit, oral health behavior, general medical health, and socioeconomic status. The clinical examination focused on the eroded tooth surface and dental erosion extent. SPSS v19.0 software package was utilized for statistical analysis. RESULTS: A total of 1,837 children aged 3-6 years were randomly selected in Shanghai. The overall dental erosion prevalence was 15.1 percent. Among different age groups, a relatively high prevalence of 17.1 percent was found in the 4-year-old group, and a relatively low prevalence of 12.0 percent was observed in the 3-year-old group. Surprisingly, there was no significant difference among the four age groups. The occurrence of dental erosion was influenced by habits of vinegar/coffee/tea consumption, mother's educational background, birthplace, and regurgitation (P < 0.05). CONCLUSION: The dental erosion prevalence in 3- to 6-year-old children in Shanghai appears to be close to that of other Chinese provinces as well as that observed in most of surveys carried out in different parts of the world. Efforts should be made to raise public awareness about the disease. Moreover, further studies targeted to explore the relationship between dental erosion and risk factors are needed. It is also necessary to establish a unified diagnostic standard for future epidemiological investigations.

[Relationship between ureolytic activity expression of Streptococcus salivarius urease genes ureIABCEFGD in Escherichia coli and nickel ions].

PURPOSE: To obtain the clone of Streptococcus salivarius 57.I urease genes ureIABCEFGD and investigate the relationship between ureolytic activity expression of this clone in Escherichia coli and nickel ions. METHODS: The target gene was cloned by polymerase chain reaction in 2 parts separately. Then, 2 plasmids were digested by specific restriction enzymes and ligated together. The obtained plasmids were subjected to nucleotide sequence analysis and transformed into E.coli TG-1. The recombinant E.coli was added without or with different level of NiCl2. The amount of ammonia generated by ureolytic activity of each sample was measured by Nessler's assay. SPSS 17.0 software package was used for correlation analysis. RESULTS: The clone of urease genes ureIABCEFGD was proved by sequence analysis and BLAST search. The amount of ammonia generated by the recombinant strain had a positive correlation with the level of NiCl2(r=0.9714,P<0.01). When the level of NiCl2 was 50 µmol/L, the amount of ammonia reached maximum and would have little variance despite the increase of NiCl2 level. CONCLUSIONS: Ureolytic activity expression of ureIABCEFGD has a positive correlation with the level of added NiCl2 not exceeding 50 µmol/L. The present clone can be used to further investigate the regulation of the ureolytic activity expression of Streptococcus salivarius urease gene. Supported by Natural Science Foundation of Shanghai Municipality(08ZR1416800) and Research Fund of Science and Technology Committee of Shanghai Municipality(11411950900).

[Practice and experience in early clinical education of dental students in preventive dentistry].

To help dental students acquaint the medical environment, doctor-patient communication and relationship, early clinic education was arranged in our college of stomatology. The interesting topics were chosen to enhance the learning enthusiasm of the students in the teaching practice of preventive dentistry. Students were encouraged to practice the skill of doctor-patient communication. To obtain the satisfactory teaching effect and aim, it was important to pay attention to the aspects in the groups and clinical practice. Early clinic education in preventive dentistry help the students understand the specialty of preventive dentistry.

A randomized trial on the inhibitory effect of chewing gum containing tea polyphenol on caries.

OBJECTIVE: The purpose of the study was to determine the cariostatic potential of a chewing gum containing tea polyphenol. STUDY DESIGN: A total of 157 schoolchildren aged 8-9 years were randomly allocated into three groups. Two groups received chewing gum with or without tea polyphenol. A third group did not receive any chewing gum. A single examiner assessed the caries status for all participates at baseline, 12 months and 24 months. A one-way analysis of variance (ANOVA) was performed to evaluate differences among the groups at each interval The Chi-square test was used to compare the caries-free rate among the three groups. RESULTS: The mean DMFT increment was 0.17 for the polyphenol gum group, 0.60 for the control gum group, and 1.15 for the no gum group. Children who chewed gum containing tea polyphenol had a significantly lower mean DMFS increment over the 24-month period than did the other two groups (p < 0.05). The caries-free rate in the polyphenol gum group was significantly higher than that in the other two groups (p < 0.05) after two years. CONCLUSION: These findings indicated that the oral application of chewing gum with tea polyphenol has an inhibitory effect on dental caries.

[Cloning and expression of Streptococcus salivarius urease gene in Escherichia coli].

OBJECTIVE: To clone Streptococcus salivarius (Ss) 57. I urease gene, which can express ureolytic activity in Escherichia coli (Ec) without adding extra nickel ions. METHODS: Urease gene was cloned by polymerase chain reaction in three separate parts. The three separate plasmids were digested by specific restriction enzymes and ligated together. The expression of the complete urease gene in Ec was detected by phenol red assay and pH analysis. RESULTS: Urease gene of Ss 57.I was eventually cloned and proved correct. Urease activity of the obtained clone was positive in Ec. Without adding extra NiCl(2), the recombinant Ec could hydrolyze urea to produce ammonia, resulting in the increase of pH value. CONCLUSIONS: The clone of Ss urease gene obtained in this study could express ureolytic activity in Ec without adding extra nickel ions. The current clone can be used to construct ureolytic effector strain used in replacement therapy in caries prevention.

[The relationship of halitosis and Helicobacter pylori].

PURPOSE: The aim of the study was to investigate the relationship between halitosis and Helicobacter pylori infection in stomach. METHODS: Fifty subjects without periodontal diseases and systematic disease (exclude gastrointestinal diseases) were included. Infection of H.pylori was diagnosed by biopsy and (14)C-urea breath test. SPSS11.5 software package was used to analyze the data. RESULTS: All the subjects were periodontal healthy according to the periodontal index. The prevalence of H.pylori infection in halitosis subjects was significantly higher than that in the normal subjects (57.1% VS 18.2%, P<0.01). Logistic regression analysis showed that H.pylori was the only significant variable in the equation(P<0.05). CONCLUSIONS: H.pylori in stomach may be involved in the presence of halitosis in periodontal healthy subjects.

[Effect of two kinds of chewing gums on dental plaque pH].

PURPOSE: The aim of the study was to evaluate the change of plaque pH after chewing 2 kinds of gums. METHODS: The investigation consisted of 8 healthy subjects (aged 23-27 years, 4 males and 4 females) who refrained from toothbrushing for 24 hours before the test. The pH of dental plaque was measured using a Beetrode pH microelectrode before and after sucrose challenge with a 10% sucrose solutions at 5, 10, 15, 20 minutes as the baseline data. One week later the pH of dental plaque was measured again before the rinse and then the subjects rinsed with a 10% sucrose solutions. After 1 minute the sugar-free chewing gum was given and started to chew for 5, 10, 15, 20 minutes. The pH of dental plaque was measured at the same time on the non-chewing side. One week later the same test was carried out but the chewing gum was changed to tea polyphenol gum. Dental plaque pH value were analyzed by one-way ANOVA and SNK using SPSS 10.0 software package. RESULTS: Compared with the baseline chewed either tea polyphenol gum or sugar-free gum could increase the plaque pH recovery due to the sucrose rinsing challenge and it could maintain the dental plaque pH above the resting value. There was no statistically significant difference between tea polyphenol gum and sugar-free gum (P>0.05). CONCLUSION: Both gums can increase the plaque pH and decrease the risk of caries.

[The effect of chewing gum containing tea polyphenol on salivary flow rate and pH].

PURPOSE: To investigate the change of saliva flow rate and pH after chewing tea polyphenol gum. METHODS: Saliva was collected before and after chewing tea polyphenol gum and the control gum. Both the salivary flow rate and pH value were measured and analyzed by one-way ANOVA and SNK. RESULTS: The chewing gum significantly increased the flow rate as well as pH value of the saliva. The flow rate of the tested and control gum reached peak in the first minute. They were 3.15+/-1.05 and 3.30+/-0.87 ml respectively. There was no significant difference between the chewing gums. CONCLUSION: Chewing gum can increase the secretion and elevate the pH value of the saliva which benefits oral health care.