Literature has shown that endodontic treatment is rendered most commonly following microbial aggression to the dental pulp . Recently, there has been increase in overall endodontic treatments across the world due to more patient awareness and desire to save the natural teeth. The study of endodontic epidemiology may help prediction of future needs for dental treatment in a growing dentate population since the endodontic status of a tooth is important for its survival. It may also be a useful tool in the evaluation and planning of dental education in a particular country. There are many epidemiological studies which have reported prevalence of endodontically treated teeth in respective populations by evaluating either the total number of treated teeth or the number of individuals with endodontic treatment [2-17].These studies showed that 2.3% to 21.4% of all teeth had endodontic treatment and the variation is seen along with the geographic variation of population (Table 1).
To our knowledge, the prevalence of endodontically treated teeth in the Malaysian population has never been investigated. The estimates on their prevalence have mainly been based on studies from other countries. Hence, the purpose of this study was to use radiographic examination to investigate the prevalence of endodontic treatment in an adult Malaysian population with respect to age, sex, ethnicity and type of tooth.
Materials and Methods
The sample of this cross-sectional study examined the records of total 1663 patients visiting the dental clinics of an AIMST University in Kedah state of Malaysia from July 2015 to November 2020. The patients belonged to all the states of Malaysia and satisfied the inclusion criteria which were as follows, irrespective of sex and ethnicity: Malaysian nationality, age group 18 to 75 years, visited the dental clinic in last 5 years, minimum 7 teeth present. Orthopantograms (Cranex 3d, Kavo), were retrieved from records of patients. Any radiographic evidence of presence of radio-opaque material such as root canal filling material, endodontic post or restorative material in pulp chamber was considered as Endodontic Treatment or Therapy (ET) of the tooth . Teeth were excluded whenever it was not possible to differentiate from a restoration of intact tooth without any pulpal involvement. Third molars, supernumerary teeth and faulty radiographs were also excluded.
Four independent dental professionals were designated for observation and recording the data under supervision of an experienced endodontist. The interpretation criteria were discussed while examining the radiographs. First 150 radiographs were initially examined by the observers for calibration and standardization of evaluation criteria. When a consensus was not reached after the four observers examined the radiographs, the endodontic specialist made the final decision. The interpretation of radiographs in terms of tooth showing the evidence of endodontic treatment or therapy was recorded as data along with the age, sex, ethnicity of the patients and the type of tooth. From 1663 records, a total of 33462 teeth were examined with mean 20.12 teeth per patient. A total of 16061 teeth were examined from male patients while 17401 teeth were examined from female patients (Table 2). Among the age groups, 6960 teeth were examined for patients less than 30 years of age and 4620 teeth were examined for patients above 60 years of age. Age group 31 to 40 years had maximum number of teeth examined being 11645 (Table 3).
and Indian population had 11727, 10930 and 9543 teeth examined respectively
according to ethnic groups (Table 4).
Upper left canines were the most examined teeth for the tooth-wise category
while lower left first molar were least in number to be examined when compared
to other teeth (Table 5). Data was
analysed statistically using Odds ratio, logistic regression and chi-square
test. Significance level was set at p<0.05. Interobserver agreement was
assessed using kappa (k) values.
Out of 33462 included teeth, 7856 (23.48 %) teeth showed evidence of endodontic therapy. Table 2 to table 5 shows the prevalence of the distribution of endodontically treated teeth according to gender, age groups, ethnicity and tooth type respectively. There was a significant difference among the various groups. Females (60.5%, p<0.001) showed the greater prevalence than males (Table 2). The largest number of endodontic cases were found among individuals aged 31 to 40 years (35.2%, P<0.001) (Table 3). Malay population had higher prevalence of overall ET teeth, while Indian population showed highest percentage of ET teeth within any ethnic group (Table 4). Maxillary molars and mandibular molars were the teeth in which endodontic treatment was most frequent, whereas canines showed the lowest prevalence (Table 5).These findings were in similar fashion among most of inter groups and intra groups comparison, i.e. compared to males, the females had higher prevalence of ET teeth from all ET teeth examined (27.31%) in both groups as well as all teeth examined in female group (60.5%). Interobserver agreement was excellent, since kappa values were greater than 0.9.
This study evaluated the prevalence of endodontically treated teeth in Malaysian sub-population with respect to sex, age, ethnicity and tooth type since no such study has been done earlier for this sub-continent. This methodology of this study was designed similar to many previous studies by examining radiographic images of a random sample from a database to calculate the number of endodontically treated teeth [6,7,9,18]. The inclusion criteria for cases stated the adult patients of age groups from 18 years to 75 years so that maximum number of permanent teeth could be included. The upper age limit also enabled to satisfy other inclusion criteria, minimum number of teeth present to be 7; which is one fourth of maximum 28 teeth
evaluated in a
patient. This was to avoid any false higher number of the endodontically
treated teeth per non treated teeth and to get the sample size with minimum
error . Evaluation of an orthopantograms (OPGs) was used to collect data
since these have been used very often used for such purpose in epidemiological
studies [7,18]. An OPG is an effective and more advantageous method to record
the large volume of patient data in university dental clinics where full-mouth
periapical radiographs are not used routinely [11,19]. It conveniently allows a
quick examination of all teeth using only one radiograph, thereby a lower
patient radiation dose. The ethical concept of this study did not involve any
further exposure of the patient to radiation; hence no new radiographs were
We examined a large number of patients’ records to collect a significant data that could get results closer to that truly exists. This was the main challenge faced during the study taking few years. A total of 33462 teeth from 1663 patient records were examined after excluding the cases which did not satisfy inclusion criteria. The mean number of remaining teeth per patient in this study was 20.1, which is lower than other reported in other studies [8,20,21]. This might be the reason for a higher overall percentage since lesser teeth were present per patient. Patients having seven or more teeth were counted so that teeth in function could be included and to rule out cases where teeth might have been removed following a severe periodontal disease. Had those teeth been counted, it would have resulted in far higher number of ET teeth. This studied showed that 22.81 % of examined teeth were endodontically treated, which is higher than any other population including European and American. Table 4 shows the results of the similar studies done in general populations of adult age groups from other geographic locations. Another study which revealed higher prevalence of endodontic treatment (20.5%) was done by Tsuneishi et al  for Japanese adult population. However, they used full-mouth intraoral radiographs instead of OPG which might be a factor of higher results [3,8].
The results from this study can be correlated to other studies in few areas. The percentage of root filled teeth was highest when compared to other populations but can be compared to those obtained from French and Brazilian studies [9,12] (Table 1). The high results of this study could also be related to the fact that a larger proportion of the patients attending dental school might be from lower socio-economic status having poorer oral health and available during operating dental school hours . Lack of referral to specialist might have led to extraction as the treatment of choice rather than root canal therapy for difficult cases; but this fact should not have any overall effect on percentage of ET since the extracted teeth will reduce the total number of teeth examined.
The results of this study showed that females had higher prevalence of ET cases as compared to males (P<0.01); however, the number of teeth evaluated were also more in females. The significant difference definitely suggests that females have more tendencies to undergo treatment and save the teeth, but it also might indicate that more females attended the dental clinic and additionally females have less missing teeth. These results were in agreement with previous studies [10,23], however some studies had showed that gender had no effect on frequency of ET [6,19,21]. These results are consistent with many other studies done across the globe in which males had significantly fewer remaining natural teeth than females and hence average number of root-filled teeth was also lower among males [6,7].
Among the age groups, 31 to 40 showed significantly highest prevalent ET cases while 51 to 60 years showed least (P<0.05). A study done in year 2015 for Nigerian subpopulation also revealed that younger age group patients had higher prevalence .The highest ET cases in the age group 31 to 40 can be related to the fact that it had highest number of teeth examined and other factors like higher cariogenic potential due to modern dietary habits and better awareness for saving teeth rather than choosing the extraction as treatment option. Also, younger patients have easier root canal morphology, thereby making endodontic therapy treatment of choice. This was in contradiction of findings from other studies which emphasised that younger people tend to visit the dentist more often when compared to elderly and thus they have a lower incidence of caries and periodontal diseases (14). However, in future studies this age group might present with higher prevalence due to increased awareness and dynamic nature of this disease prevalence .
Age group 51 to 60 years had lower prevalence, mainly due to lesser number of teeth present in this age group and treatment plan modification due to age needs. This was in contrary of the findings from other studies which showed the frequencies of endodontic treatment increased with age [6,12,19]. However it had the highest percentage of ET within any group, i.e. percentage of ET found in particular group to overall teeth examined in that group was 28.1, highest when compared to others (intra group comparison), this might be due to fact that increase may be a cumulative effect resulting from longer exposure to function, caries, and subsequent operative procedures . On percentage basis, 41 to 50 year group had lowest which may be due to higher number of teeth retained in this group while lesser incidence of caries leading to root canal.
This subpopulation consists of 3 major ethnic groups, namely Malays, Chinese and Indians in decreasing order of proportion . However, these proportions may differ geographically within Malaysia. The findings of ET teeth were most evident in Malay population owing to the highest number of teeth evaluated in this group. Among these groups, following sequence was observed from highest to lowest on percentage basis: Indians, Malays, Chinese, others. Although Indian ethnic group constitutes to least to Malaysian population from three major ethnic groups, still the prevalence of ET teeth was highest for this group (P<0.05). This result can be multifactorial including the socio-economic aspects and further cross-sectional studies must be done to support these findings. Least prevalence was seen in other group which constitutes very minor portion of the population .
Among the teeth examined, it was observed that molars had highest prevalence, followed by premolars, incisors and least in canines (P<0.05). Findings were more significantly higher for maxillary teeth than mandibular teeth and higher for left side than right side. There was no significant difference between first and second molars. These findings can be related to both patient and tooth factors. A better care is expected for lower and anterior teeth by the patients, thereby reducing any chance of decay and subsequent treatment. At the same time, patients may have fewer posterior teeth remaining due to choice of treatment being extraction rather than endodontic treatment.
This can be due to lack of access to specialist referral for difficult posterior endodontic cases, thereby choosing extraction. Kirkevang et al  in 2001 found that significantly more molars had been endodontically treated (8.1%) than premolars (5.4%) or anterior teeth (2.5%). Another recent studies of French and Sudanese population demonstrated that molars had higher prevalence than anteriors or premolars as endodontically treated teeth [7,26]. Other previous studies also have reported that maxillary teeth were significantly more root filled teeth (62.3%) than in the mandible (37.7%) [11,23,27].
The prevalence of endodontically treated teeth evaluated in the present study was 23.48% for a Malaysian adult population within age group of 18 to 75 years having minimum 7 teeth per individual. The prevalence is higher than that observed in epidemiological studies conducted in other countries. Endodontic treatment was most frequent in females, 31 to 40 year-olds and Indian ethnic group. First molars were most commonly treated teeth (20.25%) while canines were the least (6.06%). A higher percentage of the ET teeth suggest the strongly adverse impact of dental caries. This number might is considered high even when the concept of preserving natural teeth is still emerging to the sub- population involved in this study compared to other countries or communities. Although the data was collected from records of individuals visiting the dental clinic situated in Kedah state of northern Malaysia, a portion of them belonged to other states too. At any time in future, the prevalence of endodontic treatment will be definitely higher due to increased awareness, unless it will counter-balanced by lesser incidence of dental caries and its sequelae. These results also indicate the necessity of more educational programs and advanced training of a greater number of general dentists in Endodontics. Definitely, the access to dental care and awareness which is be different in other parts of Malaysia, would affect the prevalence; hence this population may not be representative for whole of country and additional studies may be required to investigate further for other sub-populations.
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Rahul Rathi, Senior Lecturer, Faculty of Dentistry, AIMST University, Kedah 08100 Malaysia, E-mail: firstname.lastname@example.org
Rathi R, Saroha P, Ling TS, Lim SK and Lim RY. Prevalence of endodontically treated teeth in an adult Malaysian population attending a dental school clinic (2021) Dental Res Manag 5: 12-16.
Age, Endodontic, Ethnicity, Gender, Malaysia,
Prevalence, Tooth, Treatment