# Prevalence of Root Canal Treatments among Diabetic Patients: Systematic Review and Meta-Analysis
## 4 Discussion
All these biological changes result in further progression of the periapical inflammation and impaired periapical healing, ending with the loss of the RFT [45]. The outcome of RCT among diabetic subjects and controls has been prospectively investigated [48; 49]. The rate of periapical healing was significantly lower in the diabetic group (43%) compared to that in the non-diabetic group (80%) (\(p<0.05\)) after a 12-month follow-up [49]. In another study, the clinical and radiographic cure results of a RCT performed in a single visit on patients with type 2 diabetes mellitus with PA were evaluated, concluding that type 2 diabetics had larger chronic lesions compared to those of the controlsubjects, with there being slower and delayed clinical and radiographic healing among diabetic patients [48]. A recent umbrella review concluded that diabetes is a risk factor for the outcome of RCT [26]. Diabetes can be considered as a key preoperative prognostic factor in endodontic treatment [26; 45]. In short, the greater rate of the loss of endodontically treated teeth could explain the low prevalence of RCT among diabetic patients compared with that of the general population [6]. On the other hand, a possible explanation for the lower prevalence of RFT among diabetics is also periodontal disease. Diabetic patients have a high prevalence of periodontal disease [28]. Diabetes and periodontal disease are closely linked and amplify one another, if they are not successfully controlled [50]. Considering that periodontal disease is also a leading cause of tooth loss [51], the low prevalence of RFT among diabetics could also be explained by the loss of endodontically treated teeth caused by periodontal disease. The combined effect of diabetes itself and periodontal disease can reasonably explain the low prevalence of RFT among diabetics. Finally, another possible explanation that should also be taken into account is the increase in the number of dental implant treatments that has occurred in the last three decades [52]. Dentists and diabetic patients might prefer the extraction of teeth affected by endodontic infections and their replacement by dental implants, instead of performing RCT. Regarding the articles included in the systematic review, the initial database search provided twenty-six articles. When the inclusion criteria were applied, it resulted in a systematic review of eight studies published in the first quarter of the 21 st century. All the included studies were cross-sectional studies investigating both the prevalence of AP and RCT among diabetic patients. Most of the studies [11; 13; 14; 16; 40; 41] used panoramic radiographs to detect RFT, another [21] used periodical radiographs and another one [15] used both periodical and panoramic radiographs. Although it might be thought that the detection of RFT can be performed with the same precision with panoramic and periapical radiographs, in previous studies, the prevalence of RFT has been found to be higher with the use of periodical radiographs [6]. The results of this study should be translated to the clinical practice [53]. As we have collected data on poor healing and the tendency to tooth extraction among diabetic patients, it is important to bear in mind that the prognosis of RCT can be poor among diabetic patients. However, this should not be an excuse for not focusing all the attention on making a good quality RCT. In addition, this can help dentists suspect undiagnosed diabetic patients when they recognize numerous failures of RCT. If in doubt, the patient should be referred for blood tests and additional tests to rule out diabetes. Some limitations of this systematic review should be noted. One important limitation is the low numbers of included studies and patients. The reason lies in the fact that a few studies followed a strict protocol for the selection of the individuals included in the sample. This is also the reason why none of the studies included in this systematic review and meta-analysis had a low risk of bias.