To investigate current status of periodontal health in the population at the age of 15-74 in Guangdong province and provide information for oral health care in Guangdong.

A stratified multistage randomly sampling design was applied to obtain 4 provincially representative sample groups consisted of 2784 Guangdong residents, aged at 15, 35-44, 55-64 and 65-74 respectively, with a gender ratio of half to half. The status of probing depth (PD) and loss of attachment (LOA) of the whole mouth were assessed according to the Guideline for the fourth National Oral Health Survey by using a CPI probe, and the data obtained were analyzed with SAS9.2 package.

The prevalence of shallow periodontal pocket in the 15, 35-44, 55-64 and 65-74 years old group were 0.52%, 38.54%, 49.65%, 47.22% with 0.02, 2.05, 3.74, 2.80 affected teeth on average. The corresponding percentages of deep periodontal pocket in the 4 groups were 0.05%, 3.47%, 15.97%, 9.03% with 0, 0.07, 0.31, 0.16 affected teeth on average. Prevalence and the mean affected teeth of 4-5 mm LOA were 0.10%, 26.74%, 33.68%, 35.07% and 0, 1.54, 4.33, 4.05. The prevalence and the mean affected teeth of 6-8 mm LOA were 0, 6.94%, 32.29%, 27.08% and 0, 0.24, 1.23, 0.97. The prevalence of LOA≥4 mm were 0.10%, 35.07%, 79.17%, 74.65% and the prevalence of LOA≥6 mm were 0, 8.33%, 45.49%, 39.58%. In the 35-74 years old group, the prevalence and the mean teeth with PD and LOA increased with age and reached a peak in 55-64 years old group (P < 0.05). There were no significant differences in the prevalence and the mean teeth of PD and LOA between urban and rural areas. The mean teeth of PD in 35-44 and 55-64 years old groups were significant higher in the male than the female. The prevalence and the mean teeth with LOA were both significant higher in the male than the female.

The periodontal diseases indications are common in 35-74 years old people and most necessary at the age of 55-64 in Guangdong. The periodontal health may have extensive influence on oral health status in the middle-aged and the elder population in Guangdong.

To investigate the current status of remaining teeth and edentulous jaw arch of people aged 35-44, 55-64 and 65- 74 in Guangdong province.

An equal- sized stratified multi-stage randomly sampling design was applied to select a total of 288 Guangdong residents in urban and rural areas, and the subjects were between the age of 35-44, 55-64 and 65-74, with a gender ratio of half to half. The status of remaining teeth and edentulous jaw arch were assessed according to the Guideline for the 4^th National Oral Health Survey.

88.89% subjects in the 35-44 year group had more than 28 teeth and 100% subjects had more than 20 teeth, with an average of 29.88 teeth remaining and no edentulous jaw. The average remaining teeth was 26.06 in the group of 55-64 year, with 87.50% subjects having more than 20 teeth, 59.03% subjects having 28 or more teeth, 4.16% subjects having single edentulous jaw arch, and 1.04% subjects having both edentulous jaw arch. 73.96% and 35.07% subjects in the group of 65-74 year had 20 above or 28 above remaining teeth, respectively, and the average teeth was 22.94. There were 8.34% subjects having single edentulous jaw arch and 1.39% subjects having both edentulous jaws. In the 35-44 and 65-74 year group, the prevalence of missing teeth in the female was significantly higher than the male (P < 0.05), while no significant difference was found between urban and rural areas (P > 0.05). More remaining teeth were noticed in current survey (2015) when compared to the data in 2005 (P < 0.05).

The 35-44 year people have few lost teeth, and over half of the elderly people have several lost teeth. Elderly people with edentulous arch are very few.

To investigate the dental fluorosis status of permanent teeth of a 12-year-old population of Guangdong Province to provide informational support for oral health care in Guangdong.

An equal-sized cross-sectional random-sample assessment was carried out among 1920 urban and rural residents of Guangdong Province, half male and half female, aged 12 years. We examined the dental fluorosis status of complete permanent teeth crown based on a health survey and the criteria of clinical dental fluorosis from the fourth national oral health survey. The data were analyzed by SAS9.2 to investigate the prevalence and community fluorosis index as well as gender and urban and rural differences, and compared with the prevalence of fluorosis in Guangdong Province in 2005 and 1995.

In the 12-year-old population, the prevalence of dental fluorosis was 5.05%, and the community fluorosis index was 0.108. There was no significant difference between genders (P > 0.05), but there was a significant difference between subjects from urban and rural areas (P < 0.05). There were significant differences among prevalence of dental fluorosis and community fluorosis index in 1995, 2005 and 2015-2016 (P < 0.05).

The prevalence of dental fluorosis and the community fluorosis index of 12-year-old people of Guangdong Province are relatively low, but there is an upward trend.

To investigate the current status of gingival bleeding and dental calculus in the 12- to 74-year old population in Guangdong Province with the aim of providing information to support oral health care.

A stratified, multistage, random sampling design was used to obtain 7 provincially representative sample groups consisting of 8,544 Guangdong residents aged 12, 13, 14, 15, 35-44, 55-64 and 65-74 years old with a 50/50 gender ratio. The status of gingival bleeding and dental calculus in the whole mouth was assessed according to the Guidelines of the Fourth National Oral Health Survey using a CPI probe. The resulting data were analyzed using the SAS9.2 package.

The prevalence of gingival bleeding in residents aged 12, 13, 14, 15, 35-44, 55-64 and 65-74 years old was 43.75%, 42.76%, 49.06%, 39.38%, 81.94%, 90.97%, and 84.03%, respectively, while the average number of teeth with gingival bleeding per person was 1.95, 2.07, 2.59, 2.39, 9.62, 10.36, and 9.98, respectively. In the 12-, 13-, 14-, and 15-year-old groups, peak prevalence was observed at age 14 (P < 0.05). In the 35-74-year-old group, the prevalence and mean number of teeth with gingival bleeding per person increased with age, and both parameters reached a peak in the 55-64-year-old group. The prevalence of dental calculus in the 12-, 13-, 14-, 15-, 35-44-, 55-64- and 65-74-year-old group was 40.57%, 41.09%, 45.05%, 54.84%, 98.96%, 97.22%, and 92.01%, respectively, and on average, each person had 1.61, 1.71, 2.14, 3.52, 20.30, 20.55, and 17.26 teeth, respectively, with dental calculus. The prevalence and mean number of teeth with dental calculus increased with age. In the 35- to 74- year-old group, the prevalence of dental calculus was higher in urban areas than in rural areas and the mean number of teeth with dental calculus was higher in males than in females. Otherwise, there were no significant differences in the prevalence or the mean number of teeth with dental calculus or gingival bleeding between urban and rural areas or between males and females.

There is a high prevalence of both gingival bleeding and dental calculus in all 7 age groups in Guangdong, indicating that poor oral hygiene and gingival inflammation are common in Guangdong Province.