Biomedical subjects

E C Lo

Publications and source records attributed to E C Lo.

At least 37 records · Page 2Linked to original sources

PubMed1999

Geographic distribution of private dentists in Hong Kong in 1989 and 1998.

More than 80% of the dentists in Hong Kong are in private practice and third party payment schemes are uncommon. Thus, most dentists have to work according to the rules of a free market and have to respond to the demands of the population. Using official data, it was found that the geographic distribution of private dentists was highly uneven. In 1989, the dentist to population ratio in the commercial districts was below 1:2,500 while in the new towns the ratio was larger than 1:20,000. There has been an improvement in the availability of dentists in the under-served areas during the past 10 years although there are still a considerable number of dentists practising in the areas on both sides of the Victoria Harbour.

Dentists↗

PubMed1999

Patients' satisfaction with dental services provided by a university in Hong Kong.

This study was a consumer evaluation of the dental care services provided by a university dental clinic in Hong Kong which provides dental care to all university students and staff and their dependents. The objectives of this study were to study the consumers' satisfaction with the dental services; to identify their reasons for not using the dental services; and to compare the opinions of the students with those of the university staff and their spouses. A total of 140 students and 180 staff and their spouses were randomly selected for this study. The response rates were 100 per cent for students and 77 per cent for staff and their spouses. Results showed that both groups of respondents were satisfied with the quality of dental services provided by the university dental clinic. However, they were not satisfied with the long waiting time for an appointment. Students who had not attended the university dental clinic commonly stated that they were busy and had no time for a dental visit. Conversely, many staff and their spouses did not seek care from the university dental clinic because they thought that the fees were high. Although the overall Dental Satisfaction Index (DSI) scores for the students (64.5) and staff and their spouses (65.1) were similar, there were differences in the aspects of the services with which the two group were satisfied or dissatisfied. Thus if the university dental clinic wants to implement changes so as to improve consumer satisfaction and utilisation, a careful analysis of the specific opinions of its various consumer groups is required.

Chi-Square Distribution↗

PubMed1999

Dental caries status and treatment needs of 12-13-year-old children in Sichuan Province, southwestern China.

OBJECTIVE: To update information on the dental caries status of children living in the Southwestern part of China for planning appropriate dental care services and to obtain information on caries level in rural areas. METHOD: All first year students studying in seven secondary schools (two in urban, two in peri-urban and three in rural areas) in Sichuan Province were surveyed. The students were clinically examined in their schools using procedures and diagnostic criteria recommended by the World Health Organization. RESULTS: A total of 1,542 children, 12-13 years of age, were examined of which 660, 519 and 363 were from the urban, peri-urban and rural schools respectively. The prevalence of caries experience was highest in urban children (30%), followed by peri-urban children (21%) and lowest in rural children (13%). The respective DMFT index scores for the urban, peri-urban and rural children were 0.62, 0.38 and 0.18. The differences were statistically significant (P < 0.001). The major component of the DMFT index was untreated decay (DT) in all three areas. CONCLUSION: There was a clear trend of increasing prevalence and severity of dental caries in children as the survey sites moved from rural, through peri-urban to urban areas. Thus, estimates of dental caries in Chinese child populations of this age based on surveys conducted in urban areas will probably lead to gross over-estimation as over 80% of the people live in rural areas.

Adolescent↗

PubMed1999

Clinical investigation of a high-strength glass ionomer restorative used with the ART technique in Wuhan, China: one-year results.

OBJECTIVE: To evaluate the safety and effectiveness of a new glass ionomer restorative, ChemFlex, and to compare its clinical performance and wear to another popular material, Fuji IX GP, when used with the atraumatic restorative treatment (ART) approach in posterior teeth in school children. METHODS: Ninety-two subjects aged between 6 and 14 years who had bilateral matched pairs of carious posterior teeth were selected. A split-mouth experimental design was used in which the two restorative materials were randomly placed on contralateral sides. The restorations were assessed directly and also indirectly from color transparencies and die replicas. RESULTS: After one year, the success rates of ART restorations in the primary teeth were 96.6% for ChemFlex restorations and 89.7% for Fuji IX GP restorations placed in the Class I cavity preparations, whereas only 46.2% (ChemFlex) and 61.5% (Fuji IX GP) of Class II restorations were assessed as clinically satisfactory. In the permanent dentition, the success rates were 94.6% and 98.2% for ChemFlex and Fuji IX GP, respectively; however, there was no statistically significant difference between the two restoratives for either the permanent or primary teeth. The mean occlusal wear after one year in the permanent teeth was 53.2 microns for ChemFlex and 56.3 microns for Fuji IX GP. Again, there were no statistically significant differences in wear between the two materials (P > 0.05). CONCLUSION: The clinical performance of both ChemFlex and Fuji IX GP over a 12-month period was highly satisfactory and completely adequate for the ART technique, particularly in Class I cavities.

Adolescent↗

PubMed1998

Arresting dentine caries in Chinese preschool children.

OBJECTIVES: To investigate the incidence of rehardening of caries lesions in children in Southern China taking part in a preventive programme. DESIGN: Longitudinal study. SAMPLE AND METHODS: A prevention programme was established for 168 3-6-year-old children in a kindergarten (KG1), which included regular oral health education sessions and a daily toothbrushing exercise using fluoridated toothpaste (1000 ppm F). A group of 121 children studying in two other kindergartens without a preventive programme formed the controls. Due to lack of resources and dental personnel, restorative and other curative treatments were not provided. RESULTS: Rehardening of dentine caries (arrested caries) was found in children in both test and control groups. At the third annual examination, 45% of the caries lesions on the proximal surfaces of primary anterior teeth in KG1 children found at the baseline and previous annual examinations had become arrested. A multiple linear regression analysis indicated that baseline ds score and its interactions with the prevention programme, gender and the child's oral hygiene all had significant effect on the number of tooth surfaces with arrested caries at the third annual examination. CONCLUSION: Results from this study support the use of simple prevention programmes to stabilize the caries situation in communities where intensive use of trained dental personnel is not feasible.

Chi-Square Distribution↗

PubMed1998

Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in young Chinese adults.

The aim of this study was to determine the presence or absence of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in young Chinese adults and to examine the A. actinomycetemcomitans isolates from positive subjects with regard to the serotype distribution, presence of the leukotoxin gene lktA and the promoter for the leukotoxin operon as well as the incidence of phage Aa phi 23. Sixty subjects, working in a knitting factory in the Province of Guangzhou, People's Republic of China, were investigated. Subgingival microbial samples were taken from both upper first molars. They were cultured both anaerobically and in 5% CO2. P. gingivalis was found in 33 subjects. On average, it constituted 7% of the total anaerobic cultivable counts. A. actinomycetemcomitans was detected in 37 subjects of which seven yielded counts > 10(5). Twenty-one subjects were positive for both organisms. A. actinomycetemcomitans serotype a was found in 9 subjects, serotype c was found in 23 and serotype e in 5. A. actinomycetemcomitans serotypes b and d were not detected in any subjects. Presence of the leukotoxin gene lktA was demonstrated for all A. actinomycetemcomitans isolates; however, none of the A. actinomycetemcomitans strains from the present study had a deletion in the promoter region of the leukotoxin operon. The results of this investigation show a high frequency of the putative periodontal pathogens P. gingivalis and A. actinomycetemcomitans and corroborate the concept that there is variation in virulence and pathogenic potential among isolates from different subjects.

Adolescent↗

PubMed1998

Prevention of early childhood caries--results of a fluoride toothpaste demonstration trial on Chinese preschool children after three years.

OBJECTIVES: This field demonstration trial evaluates the long-term effects of introducing daily toothbrushing with fluoride toothpaste in a Chinese kindergarten (test group) compared to caries development in children who had no organized preventive program (control group). METHODS: In the test group teacher-supervised toothbrushing was initiated with 1,000 ppm MFP toothpaste in addition to oral health education activities. Test and control children were examined at baseline (n = 289, aged 3 years) and annually thereafter. RESULTS: After three years, 251 children (87%) were still in the trial. Caries development (dmfs) calculation included only those children who were present at both baseline and subsequent annual examinations. At baseline the mean dmfs was 4.8 in the test group and 6.5 in the control group (NS). After three years the caries increment was 6.2 and 8.4 in the test group and the control group, respectively (P < .05). Adjusting for reversals, the net caries increment was 3.6 and 6.3, respectively (P < .01). Additionally, multiple linear regression analysis indicated that both baseline dmfs, the program and plaque level had a significant effect on the net caries increment. The use of hierarchical caries severity zones was useful for the identification of those children most at risk for further caries development. CONCLUSIONS: We conclude that a daily toothbrushing with limited involvement of professional staff was feasible in a Chinese kindergarten and that caries development was significantly slowed in the test children. Caries severity zones may possibly assist in determining levels of intervention.

Cariostatic Agents↗

PubMed1998

Determinants for dental visit behavior among Hong Kong Chinese in a longitudinal study.

OBJECTIVES: The aim of this research was to study the major determinants for dental services utilization among middle-aged Hong Kong Chinese in a longitudinal study using an expanded Andersen and Newman model as the theoretical framework. METHODS: A random sample of 372 middle-aged Hong Kong Chinese were interviewed and clinically examined in an oral health survey. The findings were explained to the subjects and they were advised to seek care from their own dentist as appropriate. RESULTS: A total of 322 subjects were interviewed over the telephone after 12 months. About half had visited a dentist within the study period. Results of the bivariate analysis showed that proportionally more subjects who had dental benefit coverage, had prevention-oriented attitudes, were regular users of dental services, had received counseling from a dentist, or had more filled teeth at the baseline examination had visited a dentist within the study period. Logistic regression analysis produced a final model consisting of seven factors and three interaction terms that was able to classify 68 percent of the subjects into the correct user category. CONCLUSION: The expanded Andersen and Newman model was useful as a theoretical framework in studying the dental services utilization behaviors of the Hong Kong adults.

Adult↗

PubMed1997

Patterns of dental caries severity in Chinese kindergarten children.

The dental caries status of a population group is traditionally described by mean values of decayed, missing and filled teeth or surfaces (DMFT or S). Because of the limitations of the DMF values alone, additional measures of dental caries become important. A system of describing the pattern of dental caries attack hierarchically according to severity of caries was suggested by Poulsen & Horowitz (Community Dent Oral Epidemiol 1974;2:7-11). The purpose of the present study was to analyze caries data from a group of 3-6-year-old Chinese kindergarten children according to this hierarchical system, assess the hierarchical assumptions of the system with deciduous teeth and evaluate its usefulness as an additional caries description for a kindergarten population. As part of a longitudinal field trial, baseline caries data were collected from 452 children. Caries was registered by tooth surface without the use of radiographs. Each child was assigned to one of six mutually exclusive zones of increasing caries severity, from zone 0=caries free through zone 5, the most severe, assuming that once a child was classified into a given zone it automatically belonged to all zones of lesser severity (except zone 0). On the basis of the original six zones, 61% of the children were classified correctly according to the hierarchical concept, but different alternative models which merged one or more zones together demonstrated varying percentages of correct classification, the cariologically most acceptable one placing 83% correctly. For each age group there was a close correlation between mean dmfs and increasing severity. The hierarchical model provides a valuable additional description of the caries status in deciduous teeth and is consistent with professional and epidemiological knowledge of caries attack patterns.

Age Factors↗

PubMed1997

Therapeutic effects of supervised chlorhexidine mouthrinses on untreated gingivitis.

AIM: The aim of the present study was to test the presumptive therapeutic effect of chlorhexidine digluconate in a population with untreated gingivitis and presence of abundant calculus. SETTING AND STUDY DESIGN: Sixty subjects (approximately mean age of 23.4) were recruited from a knitting factory in the Province of Guangdong, People's Republic of China. By applying a double-blind clinical trial design the participants were divided into two groups (Test and Control) and matched according to their mean GI scores. The Test group (n = 20) was assigned to two daily mouthrinses for 6 days per week using 0.12% chlorhexidine digluconate (Peridex). The Control group (n = 40) rinsed twice daily with a placebo solution. All the rinsings were supervised and timed for 45 s. No attempt was made to influence the oral hygiene habits of the participants. Prior to and after 3 months of the supervised rinsing, plaque was scored using the Plaque Index system (PII), and gingivitis was assessed using the criteria of the Gingival Index system (GI). Calculus was scored according to the Calculus Surface Severity Index system (CSSI), and stain was also graded by the Discoloration Index system (DI). RESULTS: After 3 months, the Test group (n = 13) showed significant reduction in mean PII, GI and percentage of gingival bleeding (GB%), while significant increases in mean DI were observed. The improvement in gingival health was observed at all regions with marked reduction in mean GI (from GI = 1.40 to 1.08) and GB% reduction by 24-52%. The proportion of GI = 2 was also reduced significantly from 50-36%. The Control group (n = 23) also showed a decrease in mean PII but significant increases in the mean GI and GB%. Intergroup comparison showed statistically significant differences between mean GI, percentage of gingival bleeding (GB%) and mean DI for the test and control groups after 3 months of supervised rinsing. However, there were no significant intergroup differences for mean PII. CONCLUSION: In conclusion, there was a significant effect of chlorhexidine on gingivitis, although the effect may be too limited to assure prognostic benefits in the prevention of future disease progression.

Adolescent↗

PubMed1996

The oral prevalence of aerobic and facultatively anaerobic gram-negative rods and yeasts in semi-recluse human vegetarians.

Limited data exist on the oral ecology of vegetarians. Hence the dental and periodontal status, and the oral prevalence of aerobic and facultatively anaerobic Gram-negative rods (AGNR) and yeasts, were studied in 36 semi-recluse, vegetarian, Buddhist monks and nuns in Hong Kong. The oral prevalence of AGNR and yeasts was 61.1% and 33.3%. There was no correlation between the prevalence of AGNR and/or yeasts and the incidence of carious or filled teeth and the health status of the periodontium. Rather, the results of this study combined with those of previous studies suggest that increasing age and the consumption of food prepared in communal kitchens might be more important contributory factors in the oral prevalence of AGNR than the nature of the diet itself or the health of the dentition and periodontium.

Adult↗

PubMed1995

Oral health and dental care in Hong Kong.

With a population of six million people and situated at the South-eastern corner of mainland China, Hong Kong is considered as the gateway between East and West, often playing a role disproportionate to its territorial or population size. The FDI World Dental Congress 1995 provides an impetus to familiarise colleagues worldwide with the oral health and dental care situation in Hong Kong. Water fluoridation was introduced in 1961, which has achieved a continuous low and stable caries prevalence in children as well as in adults. Edentulousness among adults is usually not apparent until after age 55, but at much lower rates than in comparable western industrialised populations. Periodontal conditions in adults are dominated by calculus and shallow pockets. Overall, treatment needs are mainly oral hygiene and simple restorative treatment. Dental awareness is considered low with only a minority of the population seeking dental care on a regular basis. Traditional Chinese health beliefs are common and may influence health behaviour in terms of self- or professional care. Dental care is mainly provided by around 1000 private dental practitioners but special government dental programmes are established for primary school children, who are mainly treated by dental therapists, and for civil servants and their dependents. Dental hygienists are trained in very limited numbers. Dental specialties are under development as part of a newly established Academy of Medicine. Developments are under way to introduce new preventive oriented programmes for pre-school and secondary school age groups.

Adult↗

PubMed1994

The Hong Kong adult oral health survey--1991: background, study population, and methods.

This second adult oral health survey was conducted with the following main aims: 1) to describe the oral health conditions and to analyse the oral health care needs and demands of 65-74-yr-olds in Hong Kong, and to propose appropriate strategies for meeting their needs in the light of societal obligations; 2) to describe the oral health conditions and to analyse the oral health care needs and demands of 35-44-yr-olds in Hong Kong with special emphasis on assessment of changes in this age group since 1984 (when the first adult oral health survey was conducted); 3) to assess the impact of sociodemographic and dental care system factors on the oral health status of selected adult age groups: and 4) to utilize survey data to refine curriculum development and research strategies in the Faculty of Dentistry, as well as in the proposal of appropriate action to governmental committees on dental health policy. For enhanced comparability with the previous study, the 35-44-yr-olds were selected from the same geographic areas of Hong Kong Island. Multistage cluster sampling was used to recruit the study population, defined geographic units and addresses being used as the starting-point. A sample of 398 subjects was selected, of whom 93% were both interviewed and clinically examined. The 65-74-yr-olds were recruited from housing estates in all principal areas of Hong Kong, yielding a sample of 559 subjects, of whom 96% were both interviewed and clinically examined.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Dental health knowledge and attitudes among the middle-aged and the elderly in Hong Kong.

Previous studies on adult Hong Kong Chinese have indicated that their level of knowledge of and attitudes toward dental health might be a potential barrier to effective oral preventive efforts. The knowledge and attitudes of elderly Chinese have not previously been studied. The objectives of this study were to describe Hong Kong adults' knowledge of the causes of the two main oral diseases, caries and periodontal disease, and possible preventive measures, and to analyse possible relationships between knowledge and attitudes and selected sociodemographic and utilization variables. Two populations aged 35-44 yr (n = 398) and 65-74 yr (n = 559) were selected for the study, which was conducted as structured interviews. A knowledge score was constructed from questions on caries and periodontal disease development and prevention. Attitudes were measured in the younger group by beliefs and evaluations of those beliefs according to the theory of reasoned action (the higher the score, the more positive the attitude). Knowledge scores were almost normally distributed in the younger respondents, but were heavily skewed toward 0 in the older group. In both age groups, increased level of education and regularity or recency of dental visits were strongly associated with dental knowledge. Women, regular dental care users, and prevention-oriented respondents had higher attitude scores. There was no correlation between knowledge and attitudes. Some improvement in knowledge seems to have taken place, especially on the cause of caries, with fewer 35-44-yr-old respondents claiming lack of knowledge of the causes of caries and gum disease than in a previous study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Chinese health beliefs and oral health practices among the middle-aged and the elderly in Hong Kong.

The purpose of this paper was to study possible relationships between traditional Chinese health beliefs and health practices in adult Chinese in a modernized society. The study populations comprised 398 35-44-yr-old and 559 65-74-yr-old Hong Kong Chinese. The respondents were categorized into three groups with weak, moderate, or strong Chinese beliefs on the basis of interview questions on the causes of gum disease. Chinese preventive practices and Chinese pain practices were defined according to respondents' reported use of recommended traditional cures. Questions on generally accepted oral practices were phrased in terms of frequency of daily brushing of teeth, use of toothpicks the previous day, and whether or not teeth were flossed the previous day. Around one-third of the respondents had weak, almost one-half had moderate, and around one-quarter expressed strong Chinese health beliefs. No significant differences in Chinese health beliefs were found between men and women in either age group, or between the age groups. In the 35-44 age group, more of those with a higher education were in the "weak" Chinese health belief category, whereas, conversely, more of those with a lower education expressed stronger Chinese health beliefs (P < 0.05). Women in both age groups reported significantly more frequent brushing. Toothpicks were used by around three-quarters of both age groups, but flossing was extremely rare.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Attitudes toward dentists and the dental care system among the middle-aged and the elderly in Hong Kong.

A sample of 398 35-44-yr-old and 559 65-74-yr-old Hong Kong Chinese were interviewed by trained interviewers using a structured questionnaire in an oral health survey conducted in 1991. The present analysis aimed to describe the dental-care-seeking behaviour and attitudes of these subjects. It was found that 43% of the younger and 23% of the older age group had visited a dentist within the past year. More than half of the elderly and a quarter of the adults had not been to a dentist for 3 yr or more, and the main reason given by these subjects was that they felt that nothing was wrong. The vast majority of the subjects consulted a dentist only when they had toothache or other dental problems. Less than 20% of the 35-44-yr-olds visited a dentist for a check-up or teeth cleaning, and these subjects were described as having a prevention-oriented attitude toward oral care. The result of a logistic regression analysis showed that there was a higher chance for subjects to have this attitude if they had dental programme coverage, perceived their teeth to be good, had better dental health knowledge, had a more positive dental attitude, and were less anxious about dental care. However, the influence of these factors was quite weak, because the overall percentage of correct classification of the model was 83.7% and the sensitivity was only 23.3%.

Adult↗

PubMed1994

Use of dental services by the middle-aged and the elderly in Hong Kong.

The objectives of this analysis were to describe the dental service use pattern of the 35-44- and 65-74-yr-old age groups and to determine to what extent this pattern could be explained by selected sociodemographic and attitudinal variables. The study populations comprised 398 35-44-yr-old and 559 65-74-yr-old Hong Kong Chinese. Use of dental services was determined on the basis of the respondents' own perception of the regularity of their dental visits and by the time since the last dental visit. The younger groups was categorized into regular users, irregular users, and nonusers, and the older group was categorized into three groups according to last dental visit (within 2 yr, 2-5-yr, 5 yr or more). A modification of the Andersen and Newman model for individual determinants of health care use was used as the framework for a logistic regression analysis. Predisposing variables were sex, education, occupation, attitudes, knowledge, preventive orientation, and dental anxiety; enabling variables were Family Possession Index, income, family support and access to a dental programme; need variables were perceived conditions of teeth, dental problems, dental pain, need for treatment, normative need for treatment, and denture wearing. In general, use of dental services was low. For the 35-44-yr-olds, the best regression model (sensitivity: 62%, specificity: 95%, overall correct classification: 88%) indicated that there was an increased probability of having a regular dental care pattern if respondents were prevention oriented, had access to a dental benefit programme, had not experienced pain, had a higher income, perceived their teeth as fair or poor, and perceived a need of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Tooth and root conditions in the middle-aged and the elderly in Hong Kong.

In an oral health survey of Hong Kong Chinese conducted in 1991, a sample of 372 35-44-yr-olds and 537 noninstitutionalized 65-74-yr-olds were interviewed and clinically examined. The examination procedures, instruments, and diagnostic criteria used to detect coronal caries followed those recommended by the World Health Organization (1987). The diagnostic criteria used to assess root-surface caries were based on those used in a national oral health survey of US employed adults (National Institute of Dental Research, 1987). Calibration of examiners was conducted before the survey and the interexaminer reliability was found to be very high; the kappa statistics were 0.93 and 0.91 for the younger and older age groups, respectively. None of the 35-44-yr-olds were edentulous and 96% had 21 teeth or more. The prevalence of edentulousness among the elderly was 12%. The DMFT indices of the younger and older age groups were 8.7 and 18.9, respectively. In both age groups, MT was the major component of the DMFT index, and female subjects had a slightly higher score. The prevalences of decayed/filled roots were 7% and 26% for the 35-44- and 65-74-yr-olds, respectively. As compared with previous surveys conducted in Hong Kong, there has been a 40% reduction in the DMFT index of the 35-44-yr-olds since 1968, but little change in the tooth and root conditions was noted between 1984 and 1991.

Adult↗