ECC has become a worldwide disease, affecting both the oral and general health of children. PMCs have been demonstrated to be the most reliable and durable restorations for multiple lesions in primary molars, particularly for the children at high risk for caries.11–13 The PMCs restorative technique is not as popular in China as that in the US. This study investigated the use and views of the PMCs technique among general dental practitioners and paediatric dentists in Chengdu, China.
The results showed that approximately one-third of the respondents (30.4%) used PMCs to restore the defects in primary molars in their clinical practice, consistent with the results of previous studies in Germany and the UK.14,15 In the study conducted in Germany, general and paediatric dentists were investigated, and only 34% of the respondents routinely used the PMCs technique. Additionally, in the study conducted in the UK, 3% of the participants routinely used PMCs, with 15% infrequently, and 82% never. According to the present study, the main deterrent to the use of PMCs was a lack of knowledge of dental practitioners to place PMCs (41.7%), consistent with the results of a previous study in Indiana.16 The results also showed that the application of PMCs was associated with the academic qualification, working specialty and working experiences of dentists. Dental practitioners with higher academic qualifications were more likely to implement the PMCs restorative technique, which might be attributed to the training of the PMCs technique in different education stages. Besides, paediatric dental specialists treated more children and used more PMCs than general dental practitioners, which was consistent with a recent study.17 This might be explained by the fact that paediatric dental specialists have a higher professional understanding of children’s oral problems, treat more young patients, and are more familiar with the PMCs technique. Additionally, dentists with less working experience were more likely to use PMCs, which might be due to a higher success rate of PMCs restoration and more and more experts’ recommendation in recent years.13,18 Therefore, to promote the implementation of this technique, the importance and the knowledge of the PMCs technique should be imparted during the undergraduate education, encouraging dental undergraduates to learn and practice it systematically when they participate in resident training in paediatric dentistry. For those who have not participated in this training, especially the general dental practitioners, continuing education programs could be a preferred approach. Santamaria et al14 showed that the use of PMCs was taught as a restorative procedure in 96% of German dental schools, but 27% of dental schools did not provide this practical training. The training of the PMCs restorative technique in Chinese dental schools, however, is not clear. Future studies could investigate the use and teaching of the PMCs technique in dental schools in different regions in China.
The perceived technique complexity also appeared to be associated with practitioners’ reluctance to use PMCs, with 28.9% of the respondents believing that it was one of the obstacles to implementing the PMCs technique.14 In the present study, however, only 9.3% of respondents thought so. The low economic benefit was reported as the second leading limitation to the use of PMCs in the present study, with 14.9% of respondents believing that it was a reason for their reluctance to apply this technique. This issue was also analyzed in a previous study, which investigated general dental practitioners’ views on using PMCs.15 In that study, some general dental practitioners believed that they would develop the use of PMCs in their daily practice if the charge could increase. On the other hand, the cost was also the second leading reason (24.2%) for patients’ hesitation to choose a PMCs restoration. In addition, non-compliance of children and the unaesthetic appearance of PMCs were other limitations for dentists to use them.14,19,20 The Hall Technique has been demonstrated to exhibit a high success rate (97%) over five years in the UK and is regarded as one of several caries biological management options.21 It can restore carious primary molar teeth by seating a correctly sized PMCs over the tooth and sealing the carious lesion in, using the glass-ionomer cement. The Hall Technique could be accepted by general dental practitioners quickly given no requirement of local anesthesia, tooth preparation, or removal of the carious tissue. Moreover, BaniHani et al22 reported that the Hall Technique only cost about half of the conventional approach. Therefore, general and paediatric dentists could apply the Hall Technique to appropriate cases in their clinical practices, especially when young children accepted. However, we believe that it also poses some challenges for the dentist to select the correct size of the PMCs at first sight.
Apart from dentists’ perception, the use of the PMCs technique was also affected by the views of children and their parents. The results showed that the main reason for patients’ refusal was a lack of understanding of the merits of PMCs restorations (43.6%). Therefore, dental practitioners should attach importance to explaining the rationale of the PMCs restorative technique to the parents before treatment. The dentists’ attitudes and effective communication are crucial to gaining the trust and understanding of children and their guardians.22 Moreover, it is necessary to popularize children’s oral health knowledge and raise public awareness of the importance of childhood dental health.
Almost all (94.6%) dentists thought primary molars with multi-surfaces caries as the main indication for using PMCs, consistent with the results of a previous study in Germany.14 Ebrahimi et al23 showed that PMCs kept the lowest failure rates after 12 months in terms of restoration of primary molars with multi-surfaces defects. Besides that, PMCs are also indicated in the following situations: primary molars after pulpectomy or pulpotomy procedures, molars with developmental defects (e.g. dentinogrnrsis imperfecta, amelogenesis inperfecta and enamel hypoplasia), teeth fracture or with extensive surface loss, high carious risk and infra-occlusion, etc.24 In clinical practice, however, not only the indications, but also dentists’ experiences, the appearance, the prices, the compliance of young patients and the contra-indications should be considered for the choice of PMCs restoration.
The current study showed that the majority (57.1%) of patients who received PMCs treatment were 3–6 years of age, and only 8.8% of patients were younger than 3 years of age. The ECC prevalence for children aged 1, 2, and 3 years in mainland China was 0.3%, 17.3%, and 40.2%, respectively.25 PMCs restoration has a high success rate in ECC treatment18,26. However, the conventional method to place crowns is more complicated than the Hall Technique, requiring more cooperation of the young patients,19,21 which might be an obstacle preventing children under 3 years from receiving PMCs restorations. The Hall Technique is considered more comfortable for children to tolerate.27 Therefore, it should be incorporated into the routine treatments, especially for young children, who are reluctant to tolerate complicated treatments and local anesthesia. On such occasions, the dentist would be prompted to improve the ability to select the right size of PMCs immediately.
One of the limitations of the present study was the nonresponse bias. The response rate of the present study was only 45%, a little bit higher than that in other studies focusing on dentists.14,19 The low response rate might partly be due to the fact that some dentists were unfamiliar with PMCs, which could lead to an overestimation of the rate of implementing PMCs restoration. Another limitation was the selection bias. All the participants were members of the Sichuan Society of Stomatology, who were not the optimum representatives of the whole population of dentists in China.
Overall, the present study showed that most dental practitioners did not implement the PMCs technique in Chengdu, China. The main reasons included a lack of knowledge to use PMCs, low charge/low input-output ratio, other technical limitations (such as local anesthesia), and children’s non-compliance. Knowledge and practice of the use of PMCs should be incorporated into the routine educational curriculum of dental students during their undergraduate studies, which could enhance their understanding of this technique and encourage them to implement it to treat primary molars in their future clinical practice. Continuing education programs are also required to provide general dental practitioners with the means to learn the PMCs restorative technique. Moreover, the Hall Technique can be considered as a routine method to place PMCs, reducing the complexity of the practice, and increasing children’s cooperation. Further studies should focus on the views of dental school teachers and students on the teaching of the PMCs technique.