Background: The prevalence of root filled teeth (RFT) worldwide will inform about the amount of clinical activity of dentists dedicated to treat endodontic disease.Objectives: To carry out a systematic review with meta‐analysis answering the following question: What is the prevalence of RFT around the world? The percentage of people with at least one RFT was also investigated.Methods: A systematic review including population‐based studies using the following databases: PubMed, EMBASE and Scielo. Studies related to prevalence of RFT were included. The outcome of interest of the study was the prevalence of RFT. The meta‐analyses were calculated with the Open Meta Analyst software to determine the global prevalence of RFT. Subgroups analyses were performed comparing geographical distribution, radiographic method and year of the study (classified in 20th or 21th century). The prevalence of people with at least one RFT was also analysed.Results: Seventy‐four population‐based studies fulfilled the inclusion criteria. Twenty‐eight, forty‐four and two studies reported high, moderate and low risk of bias, respectively. No obvious publication bias was observed. Prevalence of RFT was estimated with 1 201 255 teeth and 32 162 patients. The calculated worldwide prevalence of RFT was 8.2% (95% CI = 7.3%–9.1%;p < .001). The global prevalence of people with at least one RFT was 55.7% (95% CI = 49.6%–61.8%;p < .001). In 20th century, the prevalence of RFT was 10.2% (95% CI = 7.9%–12.5%;p < .001), whereas in the 21st century the overall calculated prevalence of RFT was 7.5% (95% CI = 6.5%–8.6%;p < .001). Brazilian people (12%) and the European population (9.3%) showed the highest prevalence of RFT. In Europe, 59.6% (95% CI = 52.4%–66.8%) of people has at least one RFT.Conclusions: This review showed that root canal treatment is a very common therapy throughout the world. More than half of the studied population have at least one RFT. A limitation of the present study is that most of the studies did not consider random sampling for population selection.Registration: PROSPERO Systematic review registration number: (CRD42022329053).

Background: The healing of periapical lesions after root canal treatment (RCT) is not the result of the curative action of the treatment. The process of healing begins with inflammation, and is resolved by the clearance of the immunogen that induces the immune response. Then, the periapical tissue itself carries out the healing of the periapical lesion, by repair or by a combination of repair and regeneration, depending on the host's reparative response working properly. The ultimate objective of RCT is to achieve wound healing by removing the source of bacterial antigens and toxins, allowing chronic inflammatory tissue to become reparative tissue. Some systemic conditions increase the susceptibility of the host to infection or impair the tissue reparative response, maintaining the inflammatory process and periapical bone resorption after RCT. This can cause the failure of RCT and even the need for extraction of the affected tooth.Objective: To analyse the scientific literature on the possible influence of systemic conditions on the treatment outcomes in endodontics, as well as to discuss the biological mechanisms that may be involved.Methods: The search was carried out in PubMed, SCOPUS and EMBASE. The inclusion criteria established were original scientific articles reporting data about some systemic condition in relation to treatment outcomes in endodontics, including clinical studies and studies carried out in animal models.Results: Systemic factors (age, nutrition, stress, hormones, smoking habits), and systemic diseases, such as diabetes, cardiovascular diseases, osteoporosis, HIV infection, inflammatory bowel disease, and others, can influence or interfere in the repair of periapical tissues after RCT.Discussion: Some of these systemic diseases can alter bone turnover and fibroblast function, preventing or delaying periapical wound healing. Others can alter the microvasculature, reducing nutrients and oxygen supply to periapical tissues. As a result, these systemic conditions can decrease the success rate of RCT and provoke incomplete wound healing (typically granulomatous tissue formation) in the periapical region.Conclusions: The results of this narrative review show worse success rate of RCT, with higher percentage of postoperative radiolucent periapical lesions and higher proportion of non‐retained teeth (RFT), associated with several systemic conditions, such as smoking habits and diabetes.

Aim: Several factors influence the condition of the periapical tissues associated with root filled teeth. The primary objective of this study was to retrospectively evaluate the extent and speed of bone healing of large periapical lesions associated with nonsurgical root canal treatment or retreatment. The secondary objective was to analyse the relationship between the time to complete healing when analysed using cone beam computed tomography (CBCT) and other possible predictors that affect healing.Methodology: Seventy‐nine patients were treated during the years 2013–2020 with large periapical lesions of endodontic origin (10–15 mm) as observed on intraoral periapical radiographs (IOPAR) were included. IOPAR and CBCT were available before treatment and during the follow‐up (IOPAR every 6 months and CBCT every 12 months). The volume of periapical lesions was calculated by OsiriX Lite software. Variables such as initial volume of the lesion, age, gender, type of treatment or type of root canal filling were compared to identify the differences between healed and unhealed lesions. Pearson's Chi‐square test was used for categorical variables, the t‐test for age and the Wilcoxon test for initial volume of the lesion. The association between time to healing and the variables was assessed using univariate analysis and multivariate analysis. The Wilcoxon test was used to observe the association of healing time with categorical variables and the correlation index was measured with the quantitative variables.Results: Of the 79 cases analysed, 60 lesions (76%) were completely healed as verified by CBCT in a mean healing time of 19 months, of which 60% healed fully between 12 and 18 months. Increase in age of patient and larger initial volume of the lesion were associated with a significantly longer healing time (p < .001). Gender, filling material and type of treatment did not have a significant effect on the healing process (p > .05).Conclusions: Clinicians should be aware that periapical lesions in older patients and larger areas of bone loss take longer to heal. CBCT monitoring of large periapical lesions is critical and it can help clinicians in the decision‐making process.

After pulp infection and necrosis, the passage of microbial antigens into the periapical space causes apical periodontitis (AP). Most of the clinical forms of AP can be managed without prescribing antibiotics, only with root canal treatment and abscess drainage or, where appropriate, tooth extraction. However, the scientific literature provides evidence of inappropriate antibiotic prescriptions by dentists in the management of apical disease. Objectives: The aim of this systematic review and meta-analysis was to analyze the global pattern of antibiotic prescription in the treatment of apical disease. Methods: PRISMA Guidelines were followed to carry out this systematic review. The research question was as follows: What is the pattern of antibiotic prescription by dentists in the treatment of the different clinical forms of apical periodontitis? A systematic search was conducted on MEDLINE/PubMed, Wiley Online Database, Web of Science and Scopus. All studies reporting data about the pattern of antibiotic prescription by dentists in the treatment of apical disease were included. The meta-analyses were calculated using the Open Meta Analyst version 10.10 software. Random-effects meta-analyses were performed. The risk of bias was assessed using the Newcastle–Ottawa Scale. The certainty of evidence was assessed using GRADE. Results: The search strategy identified 96 articles and thirty-nine cross-sectional studies fulfilled the inclusion criteria. The overall percentage of antibiotic prescriptions by dentists in cases of symptomatic AP was 25.8%, and 31.5% in cases of asymptomatic AP with sinus tract present. The percentage of dentists prescribing antibiotics in cases of acute apical abscess with no/mild symptoms was 47.7%, whereas, in cases of acute apical abscess with moderate/severe symptoms, 88.8% of dentists would prescribe antibiotics. Endodontists prescribe antibiotics at a lower rate than general practitioners. The total risk of bias was considered moderate, and the final rating for the certainty of the evidence was low. Conclusions: Dentists worldwide are over-prescribing antibiotics in the management of apical disease. It is necessary to improve antibiotic prescribing habits in the treatment of endodontic infections, as well as educational initiatives to encourage the rational and appropriate prescription of antibiotics in periapical diseases.

Aim. To conduct a systematic review and meta-analysis according to the following PICO question: in extracted human permanent teeth, does preflaring, compared with unflared canals, influence the accuracy of WL determination with EAL? Material and Methods. A systematic review was conducted according to the PRISMA checklist, using the following databases: PubMed, Science Direct, Scopus, and Web of Science. Studies related to WL determination using EAL both in preflared and unflared root canals of extracted human teeth were included. The outcome of interest was the accuracy of the electronic WL determination. A quality assessment of the included studies was performed, determining the risk of bias. The meta-analyses were calculated with the 5.4 RevMan software using the inverse variance method with random effects. PROSPERO registration: CRD42021243412. Results. Ten experimental studies fulfilled the inclusion criteria, and most of them found that preflaring increases the accuracy of the EALs in WL determination. The calculated OR was 1.98 (95% CI = 1.65–2.37; p < 0.00001; I² = 10%), indicating that the determination of WL by EALs is almost twice as accurate in preflared canals. The accuracy of Root ZX in WL determination increases more than three times (OR = 3.25; p < 0.00001). Preflaring with Protaper files significantly increases the accuracy of EALs (OR = 1.76; p < 0.00001). The total risk of bias of the included studies was low. No obvious publication bias was observed. Conclusions. The results indicate a significant increase in the accuracy of WL determination with EAL after preflaring, doubling the percentage of exact measurements. Preflaring should be recommended as an important step during mechanical enlargement of the root canal, not only because it improves the access of the files to the canal, but also because it allows one to obtain more accurate electronic determinations of WL.

Aim: Crohn's disease (CD) and ulcerative colitis (UC) are two chronic recurrent inflammatory processes of the gastrointestinal tract, grouped under the name inflammatory bowel disease (IBD), causing clinical episodes of intestinal inflammation. The aim of this study was to investigate the possible association between IBD and the prevalence of apical periodontitis (AP) and root canal treatment.Methodology: A case–control study design matched to age and sex was used. The study group (SG) included 28 patients with IBD (13 with CD, 15 with UC). Another 28 healthy subjects, without IBD and age‐ and sex‐matched, were included in the control group (CG). Radiographic records were analysed and AP was diagnosed as radiolucent periapical lesions (RPLs), using the periapical index score. Student's t‐test, χ² test and multivariate logistic regression were used in the statistical analysis.Results: In the CG, only 17 subjects (61%) had at least one tooth with AP, whilst in the SG group they were 23 patients (82%; OR = 2.98; 95% CI = 0.87–10.87; p = .08). The number of subjects with one or more root filled teeth (RFT) in the CG was 14 (50%), whilst in the SG they were 22 (79%; OR = 3.67; 95% CI = 1.14–11.79; p = .026). At least one RFT with AP was evident in three subjects (10.7%) in the CG, whilst in the SG 15 patients (53.6%) showed RFT with AP (OR = 9.60; 95% CI = 2.35–39.35; p = .001). In the multivariate logistic regression analysis, only endodontic status was found to be associated with IBD (OR = 1.86; 95% CI = 1.24–2.80; p = .003).Conclusion: IBD, UC and Crohn’s disease are associated with higher prevalence of RFT and higher percentage of RFT with periapical lesions. Dentists should consider these findings when caring for IBD patients by monitoring the evolution of periapical lesions of endodontically treated teeth.