Cigarette smoking increases the risk of root canal treatment

miRNAs mediate the impact of smoking on dental pulp stem cells via the p53 pathway

Cigarette smoke changes the genomic and epigenomic imprint of cells. In this study, we investigated the biological consequences of extended cigarette smoke exposure on dental pulp stem cells (DPSCs) and the potential roles of miRNAs. DPSCs were treated with various doses of cigarette smoke condensate (CSC) for up to 6 weeks. Cell proliferation, survival, migration, and differentiation were evaluated. Cytokine and miRNA expression were profiled. The results showed that extended exposure to CSC significantly impaired the regenerative capacity of the DPSCs. Bioinformatic analysis showed that the cell cycle pathway, cancer pathways (small cell lung cancer, pancreatic, colorectal, and prostate cancer), and pathways for TNF, TGF-β, p53, PI3K-Akt, mTOR, and ErbB signal transduction, were associated with altered miRNA profiles. In particular, 3 miRNAs has-miR-26a-5p, has-miR-26b-5p, and has-miR-29b-3p fine-tune the p53 and cell cycle signaling pathways to regulate DPSC cellular activities. The work indicated that miRNAs are promising targets to modulate stem cell regeneration and understanding miRNA-targeted genes and their associated pathways in smoking individuals have significant implications for disease control and prevention.

Assessment of Systemic Condition and Smoking Impact Over Incidence of Apical Periodontitis

This study aimed to assess the prevalence of apical periodontitis in a subset of the population of south-eastern Romania and to analyze the overall health status of the group of patients with apical periodontitis. The medical and dental history, including age, gender, background, presence of smoking, level of education, the total number of teeth present and with apical periodontitis, and the general health status were recorded from a total of 200 patients. The periapical status was analyzed using an orthopantomogram and periapical radiographs of teeth that were diagnosed with periapical lesions by the same dental professional. The periapical status was classified according to the periapical index (PAI), with apical periodontitis being present if the PAI score ≥3. The majority of patients were female (58.5%), with secondary or higher education from urban areas and the mean number of teeth with apical periodontitis was 2.29 ± 1.26, with a median of 2 teeth. A total of 17.1% of patients were smokers, these patients had two more teeth with periapical pathology, and 16% of all patients had general diseases, the most common of which was cardiovascular disease (8.2%). Compared with those without the disease, these patients had a higher number of teeth with apical periodontitis (median = 2.5, IQR = 2-4 vs. median = 2, IQR = 1-3). As a result, this scientific research suggests an association between smoking, cardiovascular disease, and gastritis with apical periodontitis, but no association could be demonstrated between apical periodontitis and other systemic diseases.

Impact of Smoking on the Healing of Apical Periodontitis after Nonsurgical Endodontic Treatment

OBJECTIVES

 The aim of this prospective study was to compare the healing of periapical bone between smokers and nonsmokers after root canal therapy. The effects of duration and intensity of smoking on the healing rate of apical periodontitis were analyzed.

MATERIALS AND METHODS

 Fifty-five smokers were included in this study. The control group consisted of healthy nonsmokers who matched the smoker group in age and sex. Only teeth with a favorable periodontal prognosis and adequate coronal restoration were included in the study. The periapical status of treated teeth was assessed using the periapical index system at follow-ups after 6 and 12 months.

STATISTICAL ANALYSIS

 The chi-squared test and Mann-Whitney U test were used to assess the changes in periapical index score at baseline and in subsequent time intervals between the two groups examining dichotomized and ordinal data, respectively. Multivariate logistic regression analysis was used to test the association of independent variables age, gender, tooth type, arch type, and smoking index with the outcome variable. The outcome variable was set as the presence versus absence of apical periodontitis.

RESULTS

 The analysis at 12-month follow-up revealed a significantly higher healing rate in control group than in smokers (90.9 vs. 58.2; χ2 = 13.846; p < 0.001). Smokers had significantly higher periapical index scores than the control group (p = 0.024). The multivariate logistic regression analysis demonstrated that an increase in the value of the smoking index significantly increases the risk of apical periodontitis persistence (odds ratio [OR] =7.66; 95% confidence interval [CI]: 2.51-23.28; p < 0.001) for smoking index < 400 and (OR = 9.65; 95% CI: 1.45-64.14; p = 0.019) for smoking index 400 to 799.

CONCLUSION

 The results from this study show a lower rate of apical periodontitis healing in a group of smokers at 1-year follow-up. Delayed periapical healing seems to be associated with the cigarette smoking exposure.

Effects of cigarette smoke inhalation on the immune-inflammatory profile of experimental apical periodontitis in rats

OBJECTIVE

To evaluate the effects of cigarette smoke inhalation on the immune-inflammatory profile of experimental apical periodontitis in rats.

METHODOLOGY

In total, 32 male Wistar rats were divided into four groups (n = 8): AP-induced apical periodontitis; S-cigarette smoke inhalation; APS-induced AP and cigarette smoke inhalation; and C (control)-neither AP nor cigarette smoke inhalation. To induce cigarette smoke inhalation, the animals were kept in a chamber filled with tobacco smoke for 8 min thrice a day for 50 days. AP was induced 20 days after inhalation initiation by exposing their coronary pulp to their oral environment for 30 days. After animals were euthanized, their right hemimaxillae were removed for histopathological, semi-quantitative and immunohistochemical (F4/80, CD206 and iNOS) analyses.

RESULTS

Quantitative data showed a moderate number of inflammatory infiltrates in AP and an intense number in APS (p < .05). Comparing F4/80+ cells showed no statistically significant differences among groups, but we found more CD206+ cells in AP than in C and S (p > .05). INOS+ immunostaining showed a significant increase in AP and APS, when compared with C and S (p < .05). APS had more iNOS+ cells than AP (p < .05).

CONCLUSION

Cigarette smoke inhalation worsened AP, leading to a predominantly pro- inflammatory profile in our experimental model.

Dose-response association of smoking with delayed healing of apical periodontitis after endodontic treatment

DESIGN

A prospective cohort study aimed to assess the inhibitory effect of cigarette smoking on the rate of periapical bone healing after root canal treatment (RCT). Examination included both clinical and radiographic parameters to define healing status at baseline, 6 months, and 1 year after RCT.

OBJECTIVES

To examine and compare the healing rate of apical periodontitis (AP) after RCT between smokers and nonsmokers, and to evaluate how the intensity and duration of smoking affect AP healing up to 1-year follow-up. Study hypothesis was that smoking habits could delay or deteriorate AP healing.

METHODS

The study protocol was approved by the local ethics committee and all of the participants signed a consent form. Included were adult patients with a radiographically confirmed AP in a single tooth with a favorable periodontal prognosis and adequate coronal restoration, with no previous RCT. Excluded patients were those diagnosed with a systemic disease or on medications affecting bone metabolism, former and occasional smokers, pregnant patients, and those who refused to participate. Smokers were defined as those who consumed at least 100 cigarettes in their lifetime and currently smoke. Smoking intensity was classified according to cigarette consumption per day (CPD) into: heavy smoking (≥20 CPD) and mild smoking (˂20 CPD). Tobacco exposure over time was assessed by smoking index (=CPD ˟ duration of tobacco smoking in years) and categorized into: nonsmoker, <400, 400-799, and ≥800. The control group included healthy nonsmokers and matched the smoker group in terms of age and gender. All RCTs were performed by endodontic specialists following a standardized protocol. Clinical examination involved percussion and palpation tests, periodontal probing and examination of the coronal restoration; while the periapical healing was radiographically assessed using the periapical index (PAI) scoring.

RESULTS

A total of 110 patients (55 smokers and 55 nonsmokers) were included. The two groups were comparable regarding age, gender, tooth type, socioeconomics, and periapical index scores at the baseline. The mean CPD among smokers was 12.22, and most of them were "mild smokers". At 12-month follow-up, nonsmokers showed a significantly higher healing rate compared to smokers (90.9% vs. 58.2%; χ2 = 13.846; p < 0.001). Conversely, smokers had significantly higher PAI when compared to the control group (p = 0.024). Regression analysis demonstrated that the risk of AP persistence increases with an increase in the smoking index [OR = 7.66; 95% CI: 2.51-23.28; p < 0.001, for smoking index <400 and (OR = 9.65; 95% CI: 1.45-64.14; p = 0.019, for smoking index 400-799].

CONCLUSION

Smoking was significantly associated with delayed AP healing after RCT. The likelihood of AP persistence rises as smoking exposure increases. These results could impact clinical decisions and guidelines concerning smokers.

Inflammatory profile of apical periodontitis exacerbated by cigarette smoke inhalation: Histological and immunohistochemical analysis in rats

AIM

The aim of this study was to evaluate the effects of cigarette smoke inhalation (CSI) on inflammation, pro-inflammatory mediators and haematological parameters in rats with induced apical periodontitis (AP).

METHODOLOGY

Thirty-two 3-month-old male Wistar rats were divided into four experimental groups (n = 8): C-Control; S-rats with CSI; AP-rats with AP; and SAP-rats with CSI + AP. Animals in groups S and SAP inhaled cigarette smoke by remaining inside a smoking chamber for 8 min, three times daily, for 50 days. After 20 days of smoke inhalation, animals in AP and SAP groups had the pulps of the lower right first molar exposed to oral environment for 30 days to induce AP. In these subsequent 30 days, animals in group S and SAP continued with CSI. On Day 50, animals were euthanized and mandibles were histologically processed to assess inflammatory infiltrate, immunohistochemical interleukins (IL-1β, IL-6 and TNF-α), and blood samples collected for laboratory analysis. The Mann-Whitney test was performed for non-parametric data and the pairwise analyses of Student's t-test for parametric data, with a significance level of p < .050.

RESULTS

Inflammatory infiltrate was moderate in AP group and more severe in the SAP (p = .010). The interleukins IL-6, IL-1β and TNF-α were higher in SAP group (p < .001) when compared to the AP group. A greater number of red blood cells (p = .010), haemoglobin (p = .007) and neutrophils (p = .014) were observed in the SAP group in comparison with the AP group.

CONCLUSION

Cigarette smoke inhalation induced a more severe inflammatory infiltrate, with increased levels of pro-inflammatory cytokines and changes in haematological parameters in rats with induced AP. Thus, CSI aggravated AP, exacerbating the inflammatory response.

Impact of systemic health on treatment outcomes in endodontics

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.

PROBE 2023 guidelines for reporting observational studies in endodontics: Explanation and elaboration

Observational studies play a critical role in evaluating the prevalence and incidence of conditions or diseases in populations as well as in defining the benefits and potential hazards of health-related interventions. There are currently no reporting guidelines for observational studies in the field of Endodontics. The Preferred Reporting Items for study Designs in Endodontology (PRIDE) team has developed and published new reporting guidelines for observational-based studies called the 'Preferred Reporting items for OBservational studies in Endodontics (PROBE) 2023' guidelines. The PROBE 2023 guidelines were developed exclusively for the speciality of Endodontics by integrating and adapting the 'STrengthening the Reporting of OBservational studies in Epidemiology (STROBE)' checklist and the 'Clinical and Laboratory Images in Publications (CLIP)' principles. The recommendations of the Guidance for Developers of Health Research Reporting Guidelines were adhered to throughout the process of developing the guidelines. The purpose of this document is to serve as a guide for authors by providing an explanation for each of the items in the PROBE 2023 checklist along with relevant examples from the literature. The document also offers advice to authors on how they can address each item in their manuscript before submission to a journal. The PROBE 2023 checklist is freely accessible and downloadable from the PRIDE website (http://pride-endodonticguidelines.org/probe/).

Associations of Life's Simple 7 with cerebral white matter hyperintensities and microstructural integrity: UK Biobank cohort study

BACKGROUND AND PURPOSE

The American Heart Association Life's Simple 7 (LS7) metric was used to define optimal cardiovascular and brain health, but the associations with macrostructural hyperintensities and microstructural white matter damage are unclear. The objective was to determine the association of LS7 ideal cardiovascular health factors with macrostructural and microstructural integrity.

METHOD

A total of 37,140 participants with available LS7 and imaging data from UK Biobank were included in this study. Linear associations were implemented to examine the associations of LS7 score and subscores with white matter hyperintensity load (WMH) (WMH volume normalized by total white matter volume and logit-transformed) and diffusion imaging indices (fractional anisotropy [FA], mean diffusivity, orientation dispersion index [OD], intracellular volume fraction, isotropic volume fraction [ISOVF]).

RESULTS

In individuals (mean age 54.76 years; 19,697 females, 52.4%), higher LS7 score and subscores were strongly associated with lower WMH and microstructural white matter injury, including OD, ISOVF, FA. Both interaction analyses and stratified analyses of LS7 score and subscores with age and sex showed a strong association with microstructural damage markers, with remarkable age and sex differences. The association of OD was pronounced in females and populations younger than 50 years and FA, mean diffusivity and ISOVF were pronounced in males and populations older than 50 years.

CONCLUSION

These findings suggest that healthier LS7 profiles are associated with better profiles of both macrostructural and microstructural markers of brain health, and indicate that ideal cardiovascular health is associated with improved brain health.

Evaluation of Receptor Activator of Nuclear Factor Kappa B Ligand, Osteoprotegerin, Osteopontin, and Tumor Necrosis Factor Alpha on Chronic Apical Periodontitis in Smokers

INTRODUCTION

Smoking can be considered a risk factor for chronic apical periodontitis (CAP). This study compared the immunoexpression of biomarkers receptor activator of nuclear factor kappa B ligand (RANKL), osteoprotegerin (OPG), osteopontin (OPN), and tumor necrosis factor alpha (TNF-α) in CAP in smokers and nonsmokers.

METHODS

Twelve smokers and 12 nonsmokers diagnosed with CAP and indicated for tooth extraction were selected. Exclusion factors were teeth with a diagnosis of root fracture, previous endodontic treatment, or endoperiodontal injury, in addition to individuals with systemic diseases, under 18 years of age, users of anti-inflammatory and/or antibiotics in the last 3 months, and drug users. Specimens were processed for histopathologic and immunohistochemical analysis.

RESULTS

Qualitative analysis of RANKL expression showed 66.66% weak/moderate and 33.33% strong in smokers and 100% weak/moderate in nonsmokers. OPG and OPN expressions were 100% negative to focal in the smoker group and 50% negative to focal and 50% weak/moderate in the nonsmoker group. TNF-α was 25% negative to focal and 75% weak/moderate in the smoker group and 33.33% negative to focal and 66.66% weak/moderate in the nonsmoker group. Quantitative analysis of the data using the Mann-Whitney U test showed that there was a significant difference in the immunoexpression of RANKL (P < .05), OPG (P < .05), and OPN (P < .05), but there was no statistical difference in the immunoexpression of TNF-α (P > .05) between the 2 groups.

CONCLUSIONS

These findings suggest that smoking is capable of altering the inflammatory response, influencing the evolution of CAP.

Periodontal breakdown inter-tooth relationships in estimating periodontitis-related tooth loss

OBJECTIVES

The reasons for tooth extraction are rarely recorded in epidemiological datasets. It poses a diagnostic challenge to determine if tooth loss is related to periodontal disease (TLPD). The present study aimed to assess the inter-tooth relationships based on the periodontal characteristics of existing teeth.

METHODS

A cross-sectional dataset of 8,978 participants with complete periodontal examination (including probing pocket depth [PPD] and clinical attachment loss [CAL]) in the NHANES 2009-2014 was used in this study. Spearman rank correlation was applied to assess the inter-tooth correlations of PPD/CAL among 28 teeth after adjustment for relevant confounders. We further verify our findings in the Java Project on Periodontal Disease with TLPD information available (the number of TLPD = 12).

RESULTS

Strong PPD/CAL correlations were observed in adjacent teeth (r for PPD = 0.652, r for CAL = 0.597; false discovery rate [FDR] <0.05) rather than those on non-adjacent teeth (r for PPD = 0.515, r for CAL = 0.476; FDR <0.05). The correlations increased among severe periodontitis cases (CAL ≥5 mm or PPD ≥6 mm). In line with this, we further observed that the teeth adjacent to the TLPD tooth had the most alveolar bone loss in the Java dataset.

CONCLUSION

The periodontitis parameters (PPD/CAL) of adjacent teeth could be a potential indicator to estimate TLPD when actual reasons for tooth extraction are unknown.

CLINICAL SIGNIFICANCE

Periodontally compromised teeth adjacent to a lost tooth may help estimate whether the loss could be related to periodontal disease when the actual extraction reasons are unknown.

Evolution of endodontic medicine: a critical narrative review of the interrelationship between endodontics and systemic pathological conditions

Endodontics has gained emphasis in the scientific community in recent years due to the increase in clinical and in animal models studies focused on endodontic medicine, which aims to evaluate the interrelationship between systemic and periapical tissues pathological conditions. These studies have shown that systemic changes can boost the pathogenesis of endodontic infection, favoring its development and progression. A contrary relationship is reported in numerous studies that affirm the potential of endodontic infection to trigger systemic damage and may lead to the worsening of pre-existing pathologies. Recently, the potential of filling materials to develop systemic changes such as neurological alterations had been evaluated, also showing that systemic diseases can negatively influence tissue responses to filling materials after endodontic treatment. Despite advances in endodontic medicine studies, there are still gaps in knowledge on the mechanisms of interactions between apical periodontitis (AP) and systemic diseases and much research to be done. In this sense, this critical narrative literature review aimed to show the evolution of studies in endodontic medicine to help the endodontist to know the role of systemic diseases in the pathogenesis of AP and the possible interference in the repair of periapical tissues after endodontic treatment, as well as to evidence the systemic complications that can be triggered or aggravated in the presence of endodontic infection.

Effects of electronic cigarette aerosol exposure on oral and systemic health

Conventional cigarette smoke harms nearly every organ of the body and is the leading cause of death in the United States and in the world. Decades of research have associated conventional cigarette smoke with several diseases and death. Heavily marketed, electronic nicotine delivery systems such as electronic cigarettes (e-cigarettes) are available in a variety of flavors and high nicotine concentrations. In 2019, a severe lung disease outbreak linked to e-cigarette use led to several deaths, which was called electronic-cigarette or vaping product use-associated lung injury (EVALI). Even though the trend of e-cigarette use among teens continues to increase, information on the effects of e-cigarette smoke on oral and overall health are still scarce. This review discusses the possible health effects due to unregulated e-cigarette use, as well as the health effects of second-hand smoke and third-hand smoke on non-smokers.

Comparative Evaluation of Pain Perception in Symptomatic Apical Periodontitis among Smokers and Non-Smokers Patients during Endodontic Treatment. A Clinical Prospective

Introduction:

The most common sequelae of events caused by the bacterial ingress into the tooth structures leading to pain is almost always treated by endodontic therapy, which establishes a correlation between pain and endodontics. There are many host modulatory factors that alter pain response. Smoking is one such factor that has a significant effect on human responses, immune responses, along with the risk of infection.

Methods:

A total of 10 non-smokers and 10 smokers having symptomatic apical periodontitis undergoing root canal treatment were selected. The treatment was divided into four appointments, and the patients were asked to record the interappointment pain level on a VAS scale. The data obtained were analyzed using SPSS version 20 software, and the tests employed were independent sample t-test, post-hoc Bonferroni test.

Results and Discussion:

The interappointment pain levels during the endodontic treatment were found to be higher among smokers than non-smokers. Both the groups initially showed the perception of pain, but even at the end of the treatment, smokers were found to have pain. p-value </= 0.5 was considered significant.

Conclusion:

It was concluded from the study that smokers have a higher level of pain perception when compared to non-smokers.

Smoking May Increase the Risk of Periapical Periodontitis

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

The association between smoking and periapical periodontitis: a systematic review. Aminoshariae A, Kulild J, Gutmann J.Clin Oral Investig 2020;24(2):533-545. https://doi.org/10.1007/s00784-019-03094-6.

SOURCE OF FUNDING

None. The authors declared no conflict of interest.

TYPE OF STUDY/DESIGN

Systematic review with meta-analysis.

Smoking and Radiolucent Periapical Lesions in Root Filled Teeth: Systematic Review and Meta-Analysis

AIM

This systematic review and meta-analysis aimed to investigate the association between smoking habits and the prevalence of radiolucent periapical lesions (RPLs) in root-filled teeth (RFT).

METHODS

The Population, Intervention, Comparison, and Outcome (PICO) question was: in adult patients who have RFT, does the absence or presence of a smoking habit affect the prevalence of RPLs associated with RFT? Systematic MEDLINE/PubMed, Wiley Online Database, Web of Science, Scopus, and PRISMA protocol were used to evaluate and present the results. Studies comparing smokers with control non-smoker subjects, including RFT, and providing data on the prevalence of RFT with RPLs, were included. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system was used for certainty in the evidence. The risk of bias was assessed according to Cochrane Collaboration common scheme for bias and ROBINS-I tool. Cumulative meta-analysis was performed with a random effects model. PROSPERO registration code: CRD42020165279.

RESULTS

Four studies reported data on inclusion criteria, representing data from 9257 root-filled teeth-4465 from non-smokers and 4792 from smoker patients. The meta-analysis provided an odds ratio indicating a significant association between smoking and higher prevalence of root filled teeth with radiolucent periapical lesions (OR = 1.16; 95% CI = 1.07-1.26; p = 0.0004). The certainty of the literature assessment was moderate per GRADE. The ROBINS-I tool classified three studies as low risk of bias, and the fourth as moderate risk of bias.

CONCLUSIONS

Moderate, quality scientific evidence indicates a weak but significant relationship between smoking and the prevalence of RPLs in RFT. Smoking can be considered a negative prognostic factor for the outcome of root canal treatment. Endodontic providers should be aware of the relationship between smoking and persistent apical periodontitis, assessed as RPLs, in RFT.

Cigarette Smoking and Root Filled Teeth Extraction: Systematic Review and Meta-Analysis

AIM

The aim of this systematic review and meta-analysis was to investigate the possible association between smoking habits and the occurrence of root-filled teeth (RFT) extraction.

MATERIAL AND METHODS

The Population, Intervention, Comparison, and Outcome (PICO) question was in adult patients who had RFT, does the absence or presence of smoking habits affect the prevalence of extracted RFT? Systematic MEDLINE/PubMed, Wiley Online Database, Web of Science, and PRISMA protocol was used to evaluate and present the results. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system was used for certainty in the evidence. The risk of bias was assessed according to Cochrane Collaboration common scheme for bias and ROBINS-I tool. Cumulative meta-analysis was performed with a random effects model. PROSPERO registration code: CRD42020165279.

RESULTS

After search strategy, 571 articles were recovered, seven were selected for full-text analysis, and two reported data on inclusion criteria, including 516 RFT, 351 in non-smokers, and 165 in smoker subjects. The meta-analysis provided an odds ratio indicating significant association between smoking and the prevalence of extracted RFT (OR = 3.43, 95% CI = 1.17-10.05, p = 0.02, I² = 64%). The certainty of the literature assessment was low per GRADE. Both studies were considered as moderate risk of bias.

CONCLUSIONS

Tobacco smoking should be considered a negative prognostic factor for the outcome of root canal treatment, although the quality of the evidence is low. RFT of smoking patients are three times more likely to be extracted. Continuing to smoke after endodontic treatment may increase the risk of treatment failure. However, the overall strength of evidence is low. This must be considered a limitation of the present study and the conclusion should be valued with caution.

Does tobacco smoking predispose to apical periodontitis and endodontic treatment need? A systematic review and meta-analysis

BACKGROUND

Controversial findings exist in the literature regarding the association between tobacco smoking and development of apical periodontitis or need for root canal treatment, with some studies reporting an increase in the prevalence of these outcomes in smokers, whilst others reporting no association.

AIM

To evaluate if there is scientific evidence to support an association between tobacco smoking and a greater prevalence of apical periodontitis and/or root canal treatments.

DATA SOURCES

A systematic search was performed using MeSH terms and free terms in the PubMed, Scopus, Virtual Health Library (VHL), Cochrane library and Open Gray databases.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS AND INTERVENTIONS

Observational studies that evaluated the association between smoking and the development or healing of periapical lesion and/or the prevalence of root canal treatment in humans were included.

STUDY APPRAISAL AND SYNTHESIS METHODS

A quality assessment of included studies was performed, and the relevant information and findings were evaluated. A meta-analysis using nine included studies was performed through RevMan software, and the certainty of evidence was evaluated through GRADE.

RESULTS

Fifteen studies were included, of which 10 were classified as low risk of bias, 4 were considered as moderate risk of bias and 1 as high risk of bias. Ten studies reported that smoking was associated with a greater prevalence of periapical periodontitis and/or root canal treatment. Five studies reported no association. Nine studies were included in the pooled meta-analysis, comprising two subgroups: apical periodontitis and root canal treatment. From these nine studies, eight studies were included in the apical periodontitis subgroup meta-analysis and demonstrated that this condition was significantly more prevalent in smokers when compared to the nonsmokers (odds ratio = 2.78[CI: 1.60, 4.85], P < 0.001; I²  = 79%; no adjusted odds ratio). Three studies were included in the root canal treatment subgroup meta-analysis and demonstrated an increased prevalence in smokers when compared to the nonsmokers (odds ratio = 2.73 [CI: 1.06, 2.83], P < 0.001; I²  = 72%; no adjusted odds ratio). The pooled meta-analysis demonstrated that smokers had twice the chance of having apical periodontitis and/or root canal treatment when compared to nonsmokers (odds ratio of 2.42 [CI: 1.59, 3.68], P < 0.01; I²  = 85%). The GRADE analysis demonstrated moderate certainty of evidence.

LIMITATIONS

Several confounding factors were identified such as misinformation regarding the period of time subjects had smoked, as well as the frequency of smoking and the number of cigarettes consumed. No adjustment in odds ratio data for confounding was performed.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

This systematic review and meta-analysis indicate that tobacco smokers have an increased prevalence of periapical periodontitis and root canal treatments with moderate certainty of evidence.

The association between smoking and periapical periodontitis: a systematic review

OBJECTIVES

The purpose of this systematic review was to examine if, in adult patients, the absence or presence of smoking influenced the prevalence of periapical periodontitis (PP).

MATERIALS AND METHODS

Databases were searched, and original research manuscripts up to June 2019 were identified by two reviewers. The Newcastle-Ottawa Scale (NOS) was used for risk of bias. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system was used for certainty in the evidence. A meta-analysis was performed using RevMan 5 software. Risk ratio (RR) was used for the cohort studies, and odds ratio (OR) was used for the case-control studies with 95% confidence interval (CI).

RESULTS

All the studies had many covariates and confounding variables. Three longitudinal cohort articles discussed radiographic findings as they related to the prevalence of PP in root-filled teeth. The RR of smoking and the prevalence of PP was 2.11 (95% CI 0.88-5.05, p = 0.09). Nine case-control studies focused on the prevalence of PP and smoking. There was a positive association between smoking and the prevalence of PP with an OR of 2.78 and a 95% confidence interval of 2.23-3.48, with p value < 0.05. The quality of the studies was fair per NOS, and the certainty of the literature assessment was moderate per GRADE.

CONCLUSIONS

The current best available evidence suggests that smoking was associated with the prevalence of PP but more studies are needed to report this association in the longitudinal cohort studies.

CLINICAL RELEVANCE

Smoking has a positive association with the prevalence of PP.

Time between recall visits and residual probing depths predict long-term stability in patients enrolled in supportive periodontal therapy

AIM

To relate the time between recall visits and residual periodontal probing depths (PPDs) to periodontal stability in patients enrolled in supportive periodontal therapy (SPT).

MATERIALS AND METHODS

Retrospective data on residual PPDs from 11,842 SPT visits were evaluated in SPT patients at the Medi School of Dental Hygiene (MSDH), Bern, Switzerland, 1985-2011. A residual PPD-based algorithm was developed to compute SPT intervals with no expected change of residual PPD.

RESULTS

A total of 883 patients aged 43.9 (±13.0) years and 55.4% (n = 489) being females were identified. Linear mixed model analysis yielded highest statistically significant impact on PPD change with time between SPT visits, presence of residual PPD ≥4 mm, and bleeding on probing (p < 0.0001). Patients returning for SPT five times consecutively earlier than computed presented mean % PPDs ≥4 mm of 5.8% (±3.9) compared with patients returning later (19.2%, ±7.6) (p < 0.0001). Additionally, patients attending >50% of their SPT visits earlier versus later demonstrated increased periodontal stability after 5 years (p = 0.0002) and a reduced frequency of tooth loss (0.60, ±0.93 versus 1.45, ±2.07) after 20 years (p < 0.0001).

CONCLUSIONS

To reach and maintain periodontal stability during SPT, individual quantitative data from comprehensive residual PPD profiles may contribute to the improved planning of SPT intervals.

Comparative analysis of prevalence of apical periodontitis in smokers and non-smokers using cone-beam computed tomography

Objective

The aim of this study was to compare the prevalence and size of periapical lesions among smokers and non-smokers using cone-beam computed tomography (CBCT).

Materials and methods

Retrievable CBCT datasets for 46 male patients ≥18 years during a consecutive period from 2008 to 2016 were examined. The medical, smoking history and other clinical findings (signs of previous dental trauma; Decayed Missing Filled Teeth (DMFT) scores; the percentage of root filled teeth; and oral hygiene status) were obtained. Periapical status of all included teeth was assessed by CBCT images. Statistical analysis was conducted using t-test, Pearson correlation and multiple regression.

Results

The prevalence of apical periodontitis was 13.93% in smokers and 14.26% in non-smokers with no significant difference (p = 0.936). The mean of the average size of lesions between the two groups were almost comparable, 3.50 mm in smokers and 2.89 mm in non-smokers (p = 0.567). Pearson correlation and multiple regression analysis showed that the percentage of lesion present and the average lesion size were not correlated to any independent variable.

Conclusions

While smoking is considered a risk factor for marginal periodontitis, there was no difference between smokers and non-smokers in terms of apical periodontitis.

Endodontic Microbiology and Pathobiology: Current State of Knowledge

Newer research tools and basic science knowledge base have allowed the exploration of endodontic diseases in the pulp and periapical tissues in novel ways. The use of next generation sequencing, bioinformatics analyses, genome-wide association studies, to name just a few of these innovations, has allowed the identification of hundreds of microorganisms and of host response factors. This review addresses recent advances in endodontic microbiology and the host response and discusses the potential for future innovations in this area.

Changes in periapical status, quality of root fillings and estimated endodontic treatment need in a similar urban German population 20 years later

OBJECTIVES

The study aimed at assessing, as primary objective, the periapical status and quality of root fillings, and, as secondary objective, the endodontic treatment need of a German urban population in a cross-sectional study 20 years after the first one.

MATERIALS AND METHODS

Clinical and radiographic data of 353 patients were evaluated. Descriptive and regression analyses were performed and the endodontic treatment need was calculated. Results were compared with data from the year 1993.

RESULTS

A total of 9269 teeth were examined (26.2 teeth per patient; 1993, 24.4), of which 337 teeth were root filled (3.6%; 1993, 2.7%). Prevalence of apical periodontitis in root-filled teeth was 34% (1993, 61%). Quality of root fillings was adequate in 117 cases (35%; 1993, 14%). Minimum endodontic treatment need was estimated with 1.6% (1993, 2.3%), including teeth with clinical symptoms. Considering symptomless teeth with apical periodontitis and poor quality of root filling, the treatment need was 2.9% (1993, 3.7%). Regression analysis identified quality of root filling as a significant factor for periapical health (p = 0.01, odds ratio 3.4×, 95% CI 1.9-6.3×), likewise the type of instrumentation. Teeth treated with rotary files had a significantly better outcome (p = 0.02, odds ratio 2.0×, 95% CI 1.1-3.7×).

CONCLUSIONS

Quality of root fillings and the periapical status have improved over the last 20 years in Germany. However, there is still a need for an increase in quality of root canal treatment.

Effects of nicotine on the metabolism and gene expression profile of Sprague‑Dawley rat primary osteoblasts

Smoking is a risk factor associated with bone and oral diseases, particularly periodontitis. Nicotine, the major toxic component of tobacco, is able to affect the quality and quantity of bone. Osteoblasts serve an important role in bone formation. Thus far, the effects of nicotine on metabolism‑associated gene and protein expression in osteoblasts have been controversial and the mechanisms remain unclear. The present study assessed alterations in osteogenic activity by performing a Cell Counting kit‑8 assay to investigate proliferation, Annexin V‑fluorescein isothiocyanate/propidium iodide staining to investigate apoptosis, alizarin red staining to investigate the formation of mineralized nodules, reverse transcription‑quantitative polymerase chain reaction and western blotting to investigate the mRNA and protein levels of collagen I, alkaline phosphatase, bone osteocalcin, bone sialoprotein and osteopontin; and mRNA microarray expression analysis, Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analysis to investigate the whole genome expression profile of Sprague‑Dawley (SD) rat primary osteoblasts following treatment with different concentrations of nicotine. The results demonstrated that nicotine inhibited proliferation, promoted early apoptosis and inhibited mineralized nodule formation in a dose‑dependent manner by regulating alkaline phosphatase activity and the expression of osteoblast metabolism‑associated genes and proteins. According to microarray analysis, several genes associated with bone metabolism and genes in the Hedgehog and Notch signaling pathways were downregulated significantly in nicotine‑treated osteoblasts. The results of the present study indicated that nicotine may serve an inhibitory, dose‑dependent role in SD rat primary osteoblasts that may be caused by the perturbation of genes and signaling pathways associated with bone formation. These results may provide a theoretical basis for future research regarding bone metabolism and targeted treatment of oral diseases associated with smoking.

The Effects of Smoking on the Osmotic Pressure of Human Dental Pulp Tissue

OBJECTIVE

We aimed to investigate the effect of smoking on the osmotic pressure (OP) of human dental pulp tissue.

MATERIALS AND METHODS

Sixty male dental patients (smokers and nonsmokers) scheduled for root canal treatment for prosthodontics were included in the study. Fifteen patients (1 premolar tooth/patient) were allocated to each of the following groups according to their smoking habits, i.e. group 1: ≤10 cigarettes/day, group 2: 11-20 cigarettes/day, group 3: >20 cigarettes/day and group 4: nonsmoking controls. Apical pulp tissues were removed via coronal access. Pulp tissue supernatants were obtained to measure the pulpal OP by means of a semimicro digital osmometer. One-way analysis of variance and the post hoc Duncan test were used to analyze the differences in OP between groups. Regression analysis was used to determine the relationship between the number of cigarettes smoked daily and the pulpal OP.

RESULTS

The mean (± SD) OP value decreased as cigarette consumption increased: group 4 (268.00 ± 10.09 mosm/kg) > group 1 (259.20 ± 7.16 mosm/kg) > group 2 (248.90 ± 2.23 mosm/kg) > group 3 (239.90 ± 7.40 mosm/kg). The OP differed significantly between groups (p < 0.01), and a significant negative correlation was found between cigarette consumption and pulpal OP (r = -0.809, p < 0.01).

CONCLUSION

In this study, the OP decreased as the number of cigarettes smoked increased. In clinical examination, there may be misdiagnosis of pulpal conditions in smokers (even in healthy pulp tissue) due to the effect of altered OP on pulpal tissue reactions.

Intensive Smoking-cessation Intervention in the Dental Setting

Smoking exerts detrimental effects on dental treatment and oral health. Our goal was to evaluate effectiveness in terms of the abstinence rate in smoking-cessation intervention delivered by dental professionals. Individuals who were willing to quit smoking were randomly assigned to either an intervention or a non-intervention group. Intensive intervention was provided, consisting of 5 counseling sessions, including an additional nicotine replacement regimen. Reported abstinence was verified by the salivary cotinine level. Thirty-three persons in the intervention and 23 in the non-intervention group started the trial. On an intent-to-treat basis, 3-, 6- and 12-month continuous abstinence rates in the intervention group were 51.5%, 39.4%, and 36.4%, respectively, while the rates in the non-intervention group were consistent at 13.0%. Adjusted odds ratios (95% confidence interval) by logistic stepwise regression analyses were 7.1 (1.8, 28.5), 8.9 (1.7, 47.2), and 6.4 (1.3, 30.7), respectively. Intensive smoking-cessation intervention in the dental setting was therefore effective.

High prevalence of apical periodontitis amongst smokers in a sample of Spanish adults

AIM

To study the prevalence of apical periodontitis in smoker and nonsmoker patients.

METHODOLOGY

In a cross-sectional study, the records of 180 subjects, 109 smokers and 71 nonsmokers, were examined. All participants underwent a full-mouth radiographic survey incorporating 14 periapical radiographs. The periapical region of all teeth, excluding third molars, was examined. Periapical status was assessed using the Periapical Index score. Statistical analyses were conducted using the Cohen's Kappa test, analysis of variance and logistic regression.

RESULTS

Apical periodontitis in at least one tooth was found in 74% of smokers and in 41% of nonsmokers (P < 0.01; odds ratio = 4.2; 95% C. I. = 2.2-7.9). Amongst smoker patients 5% of the teeth had apical periodontitis, whereas in nonsmoker subjects 3% of teeth were affected (P = 0.008; odds ratio = 1.5; 95% C. I. = 1.1-2.1). The percentage of root filled teeth in smoker and nonsmoker patients was 2.5% and 1.5%, respectively (P < 0.05; odds ratio = 1.7; C. I. 95% = 1.0-2.6).

CONCLUSIONS

In this study population, smoking was significantly associated with a greater frequency of root canal treatment and with an increased prevalence of apical periodontitis.

Patient feedback as a motivating force to quit smoking

OBJECTIVES

The effectiveness of a brief intervention by dental professionals utilizing feedback of oral symptoms and dental treatments specifically relevant to smoking was examined in terms of it being a motivating factor to quit smoking.

METHODS

Information pertaining to the present study was mailed to 208 dental clinics and 45 dentists agreed to participate. Dental patients who currently smoked were assigned consecutively to either an intervention (IG) or nonintervention group (NG) in each clinic during the 6-month experimental period. In IG, dental professionals provided brief explanations regarding oral symptoms and dental treatments specifically relevant to smoking. The effectiveness of intervention was evaluated with respect to attempts to quit and progression through the stages of behavioral changes involved in quitting using the standardized questionnaire.

RESULTS

Dropout was considerable; 10 clinics terminated their participation. Questionnaires of 797 patients (IG, 416; NG, 381) were received from 35 clinics and the records of 497 patients (IG, 248; NG, 249) were analyzed. Among patients in IG and NG, 12.1% and 4.8% reported attempts to quit, respectively. Odds ratios of quitting attempts and progression and regression through the stages of behavioral changes adjusted for sex, age, and stage at the first visit were 2.2 (95% confidence interval: 1.04, 4.5), 1.7 (1.1, 2.8), and 0.28 (0.15, 0.53) for all patients, respectively, and 3.1 (1.3, 7.5), 2.1 (1.3, 3.4), and 0.21 (0.11, 0.44), respectively, for patients who were not ready to quit. Trends in the movement through stages differed because of the stage at the first visit.

CONCLUSIONS

As a result of the limitation imposed by the considerable dropout number, we concluded that a brief intervention by dental professionals potentially motivates smokers with respect to their attempts to quit smoking and promotes behavioral changes involved in quitting.

Tobacco use and incidence of tooth loss among US male health professionals

Data on the dose-dependent effects of smoking and smoking cessation on tooth loss are scarce. We hypothesized that smoking has both dose- and time-dependent effects on tooth loss incidence. We used longitudinal data on tobacco use and incident tooth loss in 43,112 male health professionals, between 1986 and 2002. In multivariate Cox models, current smokers of 5 to 14 and 45+ cigarettes daily had a two-fold (HR, 1.94; 95% CI, 1.72, 2.18) and three-fold (HR, 3.05; 95% CI, 2.38, 3.90) higher risk of tooth loss, respectively, compared with never-smokers. Risk decreased with increasing time since cessation, but remained elevated by 20% (95% CI, 16%, 25%) for men who had quit 10+ years before. Current pipe/cigar smokers had a 20% (95% CI, 1.11, 1.30) increased risk of tooth loss compared with never- and former smokers of pipes/cigars.

Risk of tooth loss after cigarette smoking cessation

INTRODUCTION

Little is known about the effect of cigarette smoking cessation on risk of tooth loss. We examined how risk of tooth loss changed with longer periods of smoking abstinence in a prospective study of oral health in men.

METHODS

Research subjects were 789 men who participated in the Veterans Administration Dental Longitudinal Study from 1968 to 2004. Tooth status and smoking status were determined at examinations performed every 3 years, for a maximum follow-up time of 35 years. Risk of tooth loss subsequent to smoking cessation was assessed sequentially at 1-year intervals with multivariate proportional hazards regression models. Men who never smoked cigarettes, cigars, or pipes formed the reference group. Hazard ratios were adjusted for age, education, total pack-years of cigarette exposure, frequency of brushing, and use of floss.

RESULTS

The hazard ratio for tooth loss was 2.1 (95% confidence interval [CI], 1.5-3.1) among men who smoked cigarettes during all or part of follow-up. Risk of tooth loss among men who quit smoking declined as time after smoking cessation increased, from 2.0 (95% CI, 1.4-2.9) after 1 year of abstinence to 1.0 (95% CI, 0.5-2.2) after 15 years of abstinence. The risk remained significantly elevated for the first 9 years of abstinence but eventually dropped to the level of men who never smoked after 13 or more years.

CONCLUSION

These results indicate that smoking cessation is beneficial for tooth retention, but long-term abstinence is required to reduce the risk to the level of people who have never smoked.