The present study concentrated on all the articles reporting the prevalence of dental caries among Pakistan population. Thirty studies met the inclusion requirements and was included in this systematic review.
Even though the current research reported useful information in term of prevalence and seriousness of dental caries in Pakistani individuals, it is clear that most of the studies were conducted in Punjab and Sindh, with some studies conducted in Baluchistan, KPK, and Islamabad. The present meta-analysis, however, may not be indicative of the population as a whole. It may, however, be argued that there are similar socio-economic and cultural backgrounds among the participants.
The utilize of numerous methodologies such as: diagnosis, sample size, and recording procedures, randomization and form of study was another potential weakness that is typical in the dental caries studies. Heterogeneity and publication bias are other inevitable shortcomings of most meta-analysis research, which was also evident in current meta-analysis. We used Cochran’s Q test (χ2) and the I2 statistic for verifications: the funnel plots showed asymmetrical shape at the bottom in prevalence studies indicating presence of publication bias, which was confirmed by insignificant result of Cochran’s Q test (χ2) and the I2 statistic.
DMFT index is the most used index for measurement of dental caries at population level. According to Castro et al. [49] most of the study participant was of the opinion to use some other index yet continued to use it as according to them, they could not found more reliable method of measurement of dental caries. Almost all indices have limitation. Till date DMFT is widely used and accepted method of measuring dental caries at community level. It can only detect cavitated lesion and cannot account for incidence [50].
The overall quality of evidence in the selected studies was classified as moderate, with the majority of the studies achieving a moderate risk of bias. Seven studies was found to have low risk. The prevalence estimate of the proportion of dental caries (random effect model) was 56.32%. The identified factors for the dental caries are poor oral hygiene habits, intake of cariogenic diet and low socioeconomic status. The above findings demonstrated clearly high levels of both incidence and severity in terms of caries. In various included studies, prevalence of dental caries was reported to be varied . This is in agreement with the finding of Richardson et al. [51] that reported the frequency of dental caries in various studies differs significantly, because of many factors, including: (1) subjects studied; their age and the accessibility for examination; (2) racial and cultural factors; (3) socio-economic status; and (4) diagnostic criteria. In addition, the incidence of dental caries is typically incomparable with another in one region, so it is not possible to extrapolate findings from one ethnic group within that group [51].
As a result of many clinical studies and preventive initiatives focused on caries prevention, developed countries have less caries prevalence and a decrease in caries levels in contrast countries with good oral health system such as the Scandinavian countries, dental caries are still a continuing oral health issue [52]. There exist a continuous need of measuring incidence/prevalence of dental caries. The findings of the 2013 Child Dental Health Survey in England , Wales and Northern Ireland showed that the prevalence of caries was 31% in five-year - old kids [53]. Treatment needs for dental caries depends upon changing pattern of a disease over a time. A study from United States reported that prevalence of dental caries in school going children was low since 1960s, however incidence seems to be slightly increased from 24 % to 28% during late 1980s to 2004. [54].That is why regular monitoring of disease prevalence's over time is of essential importance. A study on 2214 Australian children aged 5 to 8 years reported prevalence of dental caries to be lower than the current pooled prevalence of 56.32% [55].
Generally, the prevalence of dental caries in the current study was 56.32%. There was high differences within the included studies with the lowest of 8% stated by Malik et al. [24] and the highest of 97% exhibited by Badar et al [32]. In general low level of reported prevalence can be because of widespread usage of fluoridated toothpaste [56] and introduction of a national oral health program [57]. Other probable reasons for such variance can be due to the various geographical areas, the variations between the individuals included in the analysis, and sample size. Oral health policies, fluoridation of community water and oral hygiene products often play a role in the variability between countries [58]. In most provinces of Pakistan, low levels of water fluoridation was observed, likewise only 22 percent of the Libyan population receives fluoridated water [59]. Consumption of foods containing sugar is high and easily available everywhere like schools, offices in Pakistan which can be one of the probable causative factor for higher rate of dental caries in the country.
The present meta-analysis found studies with certain methodological flaws such as sampling technique, sample size. Besides that we also noticed a strong publication bias. Other probable limitation observed was the geographical distribution of studies that contain data on prevalence was mainly reported from larger cities of country. A substantial region of Pakistan is still unexposed, and there still can be unexplained prevalence of dental caries. It could therefore be assumed that the findings obtained could not present the accurate picture of the prevalence of dental caries in Pakistan. There is a need for the national level population based studies with equal representation from urban and rural areas of country. In addition, future epidemiological studies should also be conducted to explore various determinant factors of dental caries in the countries. It will help the policy maker in managing the burden of dental caries in Pakistani population.