Are periodontitis and psoriasis associated? A pre-clinical murine model

AIM

To investigate the bidirectional influence between periodontitis and psoriasis, using the respective experimental models of ligature- and imiquimod-induced diseases on murine models.

MATERIALS AND METHODS

Thirty-two C57/BL6J mice were randomly allocated to four experimental groups: control (P- Pso-), ligature-induced periodontitis (P+ Pso-), imiquimod-induced psoriasis (P- Pso+) and periodontitis and psoriasis (P+ Pso+). Samples (maxilla, dorsal skin and blood) were harvested immediately after death. Measures of periodontitis (distance between the cemento-enamel junction and alveolar bone crest [CEJ-ABC] and the number of osteoclasts) and psoriasis (epidermal thickness and infiltrate cell [/0.03mm2]) severity as well as systemic inflammation (IL-6, IL-17A, TNF-α) were collected.

RESULTS

The P+ Pso+ group exhibited the most severe experimental periodontitis and psoriasis, with the highest values of CEJ-ABC, number of osteoclasts, epidermal thickness and infiltrate cells in the dorsal skin, as well as the highest blood cytokine concentration. The P+ Pso- group presented with higher cell infiltrate (/0.03mm2) compared to the control group (p <.05), while the P- Pso+ group showed substantially higher alveolar bone loss (CEJ-ABC) than the control group (p <.05).

CONCLUSIONS

Experimental periodontitis may initiate and maintain psoriasiform skin inflammation and, vice versa, experimental psoriasis may contribute to the onset of periodontitis. In a combined model of the diseases, we propose a bidirectional association between periodontitis and psoriasis via systemic inflammation.

Environmental risk factors analysis in paediatric oral health: a cross-sectional study

AIM

The aim of the present study was to evaluate the association between environmental risk factors [adherence to the Mediterranean diet (MD), eating habits, hygiene habits, body mass index (BMI)] with the presence of caries in a university-based cohort of paediatric patients.

MATERIALS

A total of 118 paediatric patients were included in the study. In addition to the evaluation of clinical (vitality test, percussion test) and radiographic (X-ray bitewing, OPT) parameters, patients' lifestyle was investigated through validated questionnaries. Data regarding decayed, missing, filled teeth index were recorded for both permanent (DMFT) and deciduous teeth (dmft). Logistic/linear regression models (crude estimates) and multiple regression models (logistic/linear) adjusted for confounding factors were built to evaluate the association between lifestyle habits and caries. The results were reported as Odds Ratio (OR - con 95% CI) for logistic regression models and Mean Difference (MD - con 95% CI) for linear models.

CONCLUSION

The present study confirmed the role of nutritional habits in caries development in the paediatric population, especially for deciduous dentition. Further clinical studies are needed to improve the quality of administered questionnaires and evaluate the cause/effect relationship between environmental risk factors and caries.

Association between apical periodontitis and secondary outcomes of atherosclerotic cardiovascular disease: A case-control study

AIM

To evaluate the association between apical periodontitis (AP) and atherosclerotic cardiovascular disease (ASCDV).

METHODOLOGY

A total of 65 periodontally and systemically healthy patients (age ≥ 40 years) were included in the study. Periapical status was assessed through dental examination and periapical radiographs; 33 subjects had AP (AP+), while 32 acted as control (AP-). Moreover, data regarding their periapical index (PAI) score and the Decayed, Missing, and Filled Teeth (DMFT) index were recorded. All subjects underwent echo-colour Doppler assessment of carotid intima-media thickness (CIMT), carotid plaques, degree of stenosis using the North American Symptomatic Carotid Surgery Trial (NASCET) method, maximum diameter of the abdominal aorta (maximum AA) and common iliac arteries (CIA) diameters. Furthermore, peripheral blood flow was also measured using the ankle-brachial index (ABI). Simple and multiple regression analyses were performed.

RESULTS

Among AP+ patients, 57.58% disclosed at least one sign of subclinical carotid atherosclerosis. Multiple regression analysis identified AP as a significant risk indicator for carotid plaques [OR = 4.87 (1.27, 18.98; p = .021)] and marked carotid intima-media thickenings (OR = 14.58 [1.22, 176.15], p = .035). A significant association was established between AP and other cardiovascular (CV) variables (CIMT, NASCET, and maximum AA). On the contrary, a higher PAI score does not correlate to increased odds of carotid alterations, and the presence of AP did not prove any significant change in CIA and ABI. No significant correlation was established between DMFT and other variables.

CONCLUSIONS

Results from the current study highlight that the presence of AP may be regarded as a risk indicator for ASCVD, with AP being associated with 5-fold increased odds of having carotid plaques and 15-fold increased odds of having marked carotid intima-media thickenings. Further studies should be conducted in order to verify whether AP treatment could be beneficial for ASCVD signs.

Are periodontitis and dental caries associated? A systematic review with meta-analyses

AIM

The epidemiological relationship between periodontitis and caries remains controversial, and evidence synthesis is currently lacking. Therefore, this systematic review was designed to answer the following PECO question: 'In human adults (P), do subjects suffering from periodontitis (E) have higher presence/number of untreated carious lesions and caries experience (O) than subjects not suffering from periodontitis (C)?'.

MATERIALS AND METHODS

Observational studies that met specific inclusion criteria established to answer to the PECO question were included. Two review authors independently searched for eligible studies, screened the titles and abstracts, carried out the full text analysis, extracted the data and performed the risk of bias assessment. In case of disagreement, a third review author took the final decision during ad hoc consensus meetings. Data synthesis was carried out through random-effects meta-analyses.

RESULTS

A total of 18 studies on 21 cohorts, involving 135,018 participants, were included. Meta-analyses showed a significant association between periodontitis and the presence of at least one tooth with either untreated carious lesions (odds ratio [OR] = 1.63; 95% confidence interval [CI]: 1.32-2.01; p <.00; I2  = 83.0%) or caries experience (decayed and filled teeth ≥ 1) (OR = 1.27; 95% CI: 1.01-1.59; p = .038; I2  = 90.0%). Moreover, subjects with periodontitis exhibited a higher number of surfaces (difference in means [MD] = 0.86; 95% CI: 0.46-1.27; p <.001; I2  = 0.0%) and teeth (MD = 0.35; 95% CI: 0.28-0.42; p <.001; I2  = 69.6%) with untreated carious lesions, as well as a higher number of teeth with caries experience (standardized difference in means  [SMD] = 1.46; 95% CI: 0.15-2.78; p = .029; I2  = 98.9%) compared with those without periodontitis. Sensitivity analyses focusing on severe periodontitis as exposure mostly showed consistent results. Estimates for caries experience were only slightly attenuated in adjusted models compared with crude models. Subgroup analyses by caries location also indicated that periodontitis was associated only with root caries, while it was not with caries affecting the anatomical crown.

CONCLUSIONS

Periodontitis was found to be associated with the presence and number of treated/untreated root carious lesions. Therefore, caries-specific preventive measures (e.g., fluorides) should be considered for individuals with periodontitis.

Multiplicative effect of stress and poor sleep quality on periodontitis: A university-based cross-sectional study

BACKGROUND

The aim of this study was to evaluate the association of perceived stress and poor sleep quality with periodontitis in a university-based cohort of individuals.

METHODS

A total of 235 individuals were included in this cross-sectional study. Perceived stress and sleep quality were evaluated through validated questionnaires, while periodontitis was identified with a full-mouth periodontal examination protocol using both European Federation of Periodontology/American Academy of Periodontology (EFP/AAP) and Centers for Disease Control and Prevention (CDC)/AAP case definitions. Simple and multiple linear and ordinal logistic regression analyses were performed to evaluate the association between perceived stress and sleep quality with periodontitis prevalence and severity.

RESULTS

Stage III/IV periodontitis resulted associated with both moderate/high perceived stress (odds ratio [OR] = 5.4; 95% confidence interval [CI]: 2.2-13.5; p < 0.001) and poor sleep quality (OR = 3.0; 95% CI: 1.2-7.4; p < 0.05). The interaction between moderate/high perceived stress and poor sleep quality presented a multiplicative association with stage III/IV periodontitis (EFP/AAP; OR = 5.8; 95% CI: 1.6-21.3; p < 0.001). Multiple linear regression analyses indicated a similar trend of association also with linear periodontal parameters, that is, mean clinical attachment level (CAL) and mean probing pocket depth (PPD).

CONCLUSIONS

The findings from the present study suggest that stress and poor sleep quality may exert a multiplicative effect on periodontitis prevalence and severity.

Comparison of physico-chemical properties of zinc oxide eugenol cement and a bioceramic sealer

The aim of the present study was to compare the physico-chemical properties of EssenSeal with AH PLUS bioceramic and Pulp Canal Sealer EWT. Flow, solubility, film thickness, radiopacity and setting time were evaluated according to ISO 6876 (2012) specifications. External and cross-section surface characteristics were analysed under a scanning electron microscope. Statistical analysis was performed using Shapiro-Wilk's test, one-way ANOVA and the Tukey HSD test. All the sealers conformed to the ISO 6876 (2012) standards, except for the setting time for AH plus bioceramic, which exceeded more than 10% of the time indicated by the manufacturer. Statistically significant differences were found between the three study sealers regarding the physico-chemical properties tested (p < 0.05). EssenSeal demonstrated characteristics respecting the ISO 6876 (2012) standards and can be considered a predictable alternative in root canal sealing.

Healthy lifestyles are associated with a better response to periodontal therapy: A prospective cohort study

AIM

To evaluate the association between lifestyle behaviours and clinical periodontal outcomes following Steps 1/2 of periodontal therapy.

METHODS

A total of 120 subjects with untreated Stage II/III periodontitis participated in this study. At baseline, questionnaires were administered to assess the following lifestyle behaviours: adherence to Mediterranean diet (MD), physical activity (PA) and stress levels, sleep quality, smoking and alcohol use. Participants received Steps 1/2 of periodontal therapy and were re-evaluated after 3 months. A composite outcome of the endpoint of therapy (i.e., no sites with probing pocket depth [PPD] ≥4 mm with bleeding on probing, and no sites with PPD ≥ 6 mm) was regarded as the primary outcome. Simple and multiple regression analyses were used to evaluate the association between lifestyle behaviours and clinical periodontal outcomes. Disease severity at baseline, body mass index, diabetes, household disposable income and plaque control were considered as confounders.

RESULTS

Multiple regression analyses showed significantly lower odds of achieving the endpoint of therapy in subjects with poor sleep quality (odds ratio [OR] = 0.13; 95% confidence interval [CI]: 0.03-0.47; p < .01), smoking (OR = 0.18; 95% CI: 0.06-0.52; p < .05) and alcohol use above the suggested intake (OR = 0.21; 95% CI: 0.07-0.63; p < .01). Subjects with a combination of 'unhealthy lifestyles' (low adherence to MD and low PA levels and high levels of stress and poor sleep quality) showed higher proportions of residual PPD≥6 mm (MD = 1.51; 95% CI: 0.23-2.80; p < .05) and lower odds of achieving the endpoint of therapy (OR = 0.85; 95% CI: 0.33-0.99; p < .05) at re-evaluation.

CONCLUSIONS

Subjects with unhealthy lifestyle behaviours showed worse clinical outcomes 3 months after Steps 1/2 of periodontal therapy.

Influence of Calcified Canals Localization on the Accuracy of Guided Endodontic Therapy: A Case Series Study

This study aimed to evaluate the precision of the guided endodontic technique applied to calcified canals in anterior teeth in relation to demographic and dental variables. The present observational study was conducted during the period 2020-2021. The patients were consecutive referrals at the Department of Endodontics and Conservative Dentistry of the University Hospital of Siena. The guided endodontics protocol was applied using 0.75 mm diameter burs for the lower teeth and 0.90 mm for the upper teeth. The inclusion criteria were as follows: (i) teeth with pulp canal obliteration (PCO) associated with a periapical lesion (periapical index (PAI) ≥ 2); (ii) teeth with PCO that require the placement of a root canal post for the execution of a prosthetic treatment; (iii) teeth in which surgical treatment was not justified. Socio-demographic characteristics of the patients were recorded and related to the drill path accuracy through the guide in the calcified endodontic canal, evaluated through a radiographic analysis, and classified as optimal (in the center of the root canal) and acceptable (deviated peripherally/tangentially). A logistic regression model was built to predict the factors that influence the poor precision of the technique. Seventeen patients (mean age 48 years) with eighteen calcified single-rooted teeth were enrolled. All teeth were associated with periapical lesions with PAI scores from 2 to 5 (mean PAI: 3.055). From the model, it is evident that the presence of a calcification affecting the apical area of the root increases the probability of being off-center with the bur by about 15 times. In addition, a previous attempt at endodontic treatment and the position in the lower arch increases the probability of non-centrality of the drill, although in a non-statistically significant way. In any of the analyzed cases, the guided endodontic technique applied to PCO did not determine the presence of iatrogenic errors, such as perforations. However, the apical localization of the obliteration increases the probability of being off-center with the drill during the instrumentation phase by about 15 times.

The Limitations of Periapical X-ray Assessment in Endodontic Diagnosis-A Systematic Review

Diagnosis is a key aspect in endodontic treatment, in a decade where invasive interventions are misapprehended as social tendency instead of medical necessity. All diagnostic facets should be considered before intending the operative phase. Intraoral endodontic radiology-based diagnosis has been shown to be limited. Periapical X-ray is the most used endodontic imaging, yet it does not provide high accuracy. Traditionally, dentists have been trained to diagnose a cyst by certain aspects (size, shape and appearance); hence, an assumption that teeth are affected by "periapical cyst" were subjected to unnecessary extraction or apicoectomy. The aim of this systematic review is to critically appraise the publications that relate the histological diagnosis of a periapical lesion (considered the gold standard) to intraoral X-ray investigation. Ovid Medline, PubMed, ScienceDirect, Mendeley and Scopus were searched for English-language studies comparing periapical diagnosis obtained by using two techniques (histopathology and X-ray). Sixteen articles were included for the final analysis (qualitative and quantitative evaluation) out of which only two supported the statement that periapical diagnosis can be coherently assessed through periapical imaging. Although there is not enough evidence to deliver a definitive conclusion, there are many publications that refute the diagnosis of a cyst via periapical X-ray.

The presence of Enterococcus faecalis in saliva as a risk factor for endodontic infection

Aim

The aim of the present study was to investigate and correlate the prevalence of Enterococcus faecalis in saliva and in root canals with different pulpal and periapical conditions.

Methodology

Sixty-seven patients were divided into five groups based on pulpal and periapical tissue status: healthy vital teeth (HVT, n=7), healthy treated teeth without lesion (HTT, n=9), irreversible pulpitis (IP, n=13), necrosis (N, n=18), and post-treatment apical periodontitis (PTAP, n=20). Saliva, rubber dam, sterility control and pre-treatment root canal samples were collected and microbiologically processed by culture method. The phylogenetic relationship of E. faecalis isolates collected from root canals and saliva were investigated by whole genome sequencing. Fisher’s exact test was used to correlate the presence of E. faecalis in root canals or saliva with clinical and/or radiographic findings. Linear/logistic regression analyses were performed to establish the relationship between the presence of E. faecalis in root canals, saliva, and the status of periapical tissues.

Results

E. faecalis was found in 18 root canal and saliva samples. E. faecalis root canal isolates were recovered with the highest frequency from post-treatment apical periodontitis. The occurrence of E. faecalis in saliva was strongly associated with its detection in the root canals (P &lt; 0.001). The pretreatment presence of E. faecalis in root canals was associated with significantly higher odds of having periapical lesions (OR=11.03; 95% CI, 1.27-95.70; p &lt; 0.05). Saliva and root canal isolates from the same patient were highly correlated at the phylogenetic level (Jaccard index &gt;0.95).

Conclusion

This pilot study confirms the role of E. faecalis in developing peri-radicular lesions in secondary endodontic infections and suggests that saliva could be the main source of infection. Further studies are needed to investigate the exact origin of this bacteria and its true role in the pathogenesis of secondary/persistent endodontic infections.

Periodontitis and low cognitive performance: A population-based study

AIM

To study the epidemiological association between periodontitis and low cognitive performance among older adults, within a representative sample of the U.S.

POPULATION

MATERIALS AND METHODS

Data from 2086 older adults (≥60 years old), representative of 77.1 million people, were retrieved from the NHANES 2011-2014 database. Periodontitis cases were identified and classified according to the AAP/CDC criteria (mild, moderate, and severe). Cognitive function was assessed through the Consortium to Establish a Registry for Alzheimer's disease (CERAD), the animal fluency test (AFT), the digit symbol substitution test (DSST), and the global cognition score. The lowest non-survey weighted quartile for each cognitive test was defined as low cognitive performance. Simple and multiple regression analyses were performed.

RESULTS

Moderate and severe periodontitis were significantly associated with a low DSST performance (OR = 1.66 and OR = 2.97, respectively). Each millimetre increase in mean CAL was associated with a lower AFT (OR = 1.44), DSST (OR = 1.86), and global cognition (OR = 1.50) performance.

CONCLUSIONS

The findings of the present study suggest the existence of an independent association between periodontitis and low cognitive performance among older adults (≥60 years old).

Association between psoriasis, sleep, and dermatological quality of life: results of a cross-sectional study

BACKGROUND

Psoriasis is a chronic relapsing inflammatory T-cell mediated disease who affects patients' daily activities and life quality. The association between sleep quality, dermatological quality of life (QoL) and psoriasis severity has been poorly investigated to date. The aim of this study is to investigate how sleep quality impacts on the severity of psoriasis, and to assess whether the different therapies used for psoriasis affect the dermatological QoL.

METHODS

We conducted a cross-sectional study on 152 adult patients based on specific questionnaires about the sleep quality (PSQI) and the dermatological quality of life (DLQI). Patients were divides into three groups according to severity (mild, moderate and severe) and therapy (group 1: no current therapy or exclusive use of topical drugs, group 2: use of conventional systemic drugs and group 3: biologics). The outcomes were expressed in the form of an Odd Ratio (OR) and for each variable it was commented whether the OR obtained was statistically significant or not.

RESULTS

Inferential statistics comparing patients' DLQI showed that patients in group 3 and group 1 had comparable results. The OR obtained allowed us to state that those not taking biological drugs have a 4-fold higher risk of developing severe psoriasis than those taking them as therapy. No statistical difference was highlighted about sleep quality.

CONCLUSIONS

This emphasizes that adequate therapy with biologic drugs allows patients with severe psoriasis to have a comparable QoL to those who are not impaired enough to require systemic or biologic therapy.

Neurocognitive abilities in children affected by sleep breathing disorders. A systematic review and meta-analysis of case control-studies

AIM

Different experimental approaches have demonstrated that children with sleep breathing disorders (SBD) exhibit neurocognitive and behavioural impairment. The present systematic review and meta-analysis aims to quantify neurocognitive deficit disorders in mouth breathing paediatric patients by summarising relevant case-controls studies. Neurocognitive assessment was undertaken with WISC.

METHODS

A search strategy was developed on electronic databases including Medline (Pubmed), Scopus, Scileo; Cochrane library from 2000 to June 2022 for published studies analysing neurocognitive skills in children with SBD compared to healthy control groups. The review was performed according to the PRISMA protocol and articles were selected according to the established inclusion and exclusion criteria. The Weighted Mean Differences (95% Confidence Intervals) were calculated between results obtained in WISC tests in SBD patients and healthy subjects.

CONCLUSION

Our results confirmed that SBD affected children performed worse than healthy children in terms of quite all the cognitive domains investigated.

Leisure-time and occupational physical activity demonstrate divergent associations with periodontitis: A population-based study

AIM

To evaluate the association between leisure-time/occupational physical activity (LTPA/OPA) and periodontitis in a nationally representative sample of the U.S.

POPULATION

MATERIALS AND METHODS

Data from 10,679 adults were retrieved from NHANES 2009-2014 database. Physical activity was assessed through the Global Physical Activity Questionnaire, and accordingly, subjects were classified as performing either high or low LTPA/OPA. Periodontal status was assessed through a full-mouth periodontal examination, and subjects were classified according to the AAP/CDC criteria (no, mild, moderate, or severe periodontitis). Simple and multiple regression analyses were applied to study the association between LTPA/OPA and periodontitis/severe periodontitis.

RESULTS

Multiple regression analyses identified high LTPA as a protective indicator for periodontitis (odds ratio [OR] = 0.81; 95% confidence interval [CI]: 0.72-0.92), while high OPA was found to be a significant risk indicator (OR = 1.16; 95% CI: 1.04-1.30). The combination low LTPA/high OPA showed a cumulative independent association with periodontitis (OR = 1.47; 95% CI: 1.26-1.72). Moreover, both high LTPA (OR = 0.72; 95% CI: 0.58-0.90) and high OPA (OR = 1.29; 95% CI: 1.09-1.53) were significantly associated with stronger estimates of severe periodontitis; the same was observed for the combination of low LTPA/high OPA (OR = 1.66; 95% CI: 1.29-2.15).

CONCLUSIONS

LTPA and OPA showed divergent associations with periodontitis.

Whitening Optical Effect of New Chewing Gums

Background:

Today, many treatments are available to enhance the color of teeth, but they require a few days to weeks to deliver this effect.

Objective:

To evaluate the instantaneous optical whitening effect of two new sugar-free chewing gums and one dentifrice of proven efficacy versus one placebo chewing gum.

Methods:

This was a single-blind, parallel trial. 424 participants entered the study and were randomly allocated to four groups. They received a personal silicone mask with a calibrated hole at one upper incisor to apply a dental colorimeter. The tools tested were chewing-gum containing indigotine (E132-FD&C Blue 2) and spirulina, chewing-gum containing only spirulina, chewing-gum placebo, and dentifrice containing Blue Covarine. Vita® Easyshade scored the tooth color, and the WIO and WID whiteness indexes were calculated. For chewing gums, the color of the teeth was scored before the assumption and after 2’30” of mastication. For dentifrice, participants brushed for 1’30”, then rinsed, and the color was scored before brushing and after 2’30”. Statistical analysis was performed by ANOVA and Tukey post-hoc.

Results:

The two experimental whitening chewing gums and the dentifrice significantly increased the WIO and the WID indexes from the baselines (p<0.001). Moreover, their effects were statistically greater than those reported for the placebo chewing gum (p<0.05) but not significatively different among them (p=NS).

Conclusion:

All the tested whitening tools showed an instant optical whitening perception. Further studies are required to assess the intensity of the effect over a prolonged time to meet the people's request for fast whitening tools.

The clinical trial registration no. is PVM-2020-01.

Effect on Dental Stains by Potassium Tripolyphosphate Added Chewing Gum

Background:

Today, people worldwide consider the discoloration of teeth the main concern, therefore, dental stains are an important problem for a lot of patients, especially for smokers, and tea and coffee consumers.

Objective:

This trial was planned to evaluate the effectiveness of a sugar-free chewing gum added with potassium tripolyphosphate, compared to a placebo chewing gum on the development or the removal of dental extrinsic stains preserving regular daily oral hygiene.

Methods:

This was a single-center, double-blind, randomized, 6-week parallel controlled clinical trial. Among those who were eligible for the trial, 162 adult participants were randomly allocated into two groups of 81 each and were instructed to maintain customary oral hygiene. All subjects started the trial period after an in-office dental visit to set the stain index baseline. They chewed one of the two chewing gums for six weeks, five pieces per day, preferably after meals and snacks, for 10 minutes. Both chewing gums were sugar-free, 2g of weight with the same size and shape. The test chewing gum contained potassium tripolyphosphate (24.4 mg per piece), the control chewing gum was identical without potassium tripolyphosphate, therefore, it did not contain any anti-stain agent. The dental extrinsic stain was measured at the first visit and at the end of six weeks by the Modified Lobene Stain Index (MLSI). Comparisons between the groups were performed using ANOVA after adjustment of the baselines, and comparisons between initial and final indexes inside the groups were performed using paired t-tests.

Results:

After the 6 weeks, 154 subjects completed the trial, 77 in each group. The mean difference in stain composite index for all sites after six weeks was 0.04±0.07 in the control group and -0.03±0.07 in the test group. This difference was statistically significant after baseline adjustment (p<0.001). Moreover, the differences in stain indexes for both buccal or lingual-palatal sites showed a statistically significant difference (p<0.001) for those using the test chewing gum versus the control chewing gum.

Conclusion:

The overall findings of this clinical study suggest that the use of chewing gum containing potassium tripolyphosphate can reduce dental stains versus placebo chewing gum on frontal teeth after six weeks of maintaining regular oral hygiene with normal tooth brushing.

Adherence to mediterranean diet, physical activity level and severity of periodontitis. Results from a University-based cross-sectional study

AIM

to evaluate the association between adherence to Mediterranean Diet (MD) and Physical Activity (PA) level with the periodontal status of a University-based cohort of individuals.

MATERIALS AND METHODS

235 individuals were included in the study. MD adherence and PA level were registered through validated questionnaires, together with a full periodontal examination. Crude and adjusted Odds ratios (ORs) [95% Confidence Interval] were calculated to evaluate the association between MD adherence, PA level and periodontitis severity. A final logistic multivariate regression model was built to evaluate the impact of the combination between low MD adherence and low PA level on the prevalence of stage III/IV periodontitis.

RESULTS

The adjusted ORs for stage III/IV periodontitis were 1.65[0.84-3.28;p = .42] for low PA and 5.63[3.21-9.84;p = .00] for low MD adherence. The final logistic multivariate regression model resulted in OR = 10.23[4.01,26.09;p = .00] of having stage III/IV periodontitis in individuals with low MD adherence and low PA.

CONCLUSIONS

Individuals conducing a lifestyle characterized by the combination of low MD adherence and lack of regular exercise had 10 times the odds to have severe forms of periodontitis. This article is protected by copyright. All rights reserved.

Sealing ability of two root-end filling materials at different retro-preparation lengths

PURPOSE

The aim of the present study was to evaluate the sealing performance, expressed as microleakage (ML), of two root-end filling materials when used at different retro-preparation lengths.

METHODS

Fifty single-rooted human teeth were collected for the study. The teeth were cut at the cement-enamel junction and endodontic treatment was performed. Each root was cut at 3 mm from the apex and then stored in wet condition. The teeth were divided into three groups according to the retro-preparation length: control group (no retro-preparation); group 1 (retro-preparation of 3 mm); group 2 (retro-preparation of 9 mm). The teeth were equally allocated to either Biodentine or Super EBA treatment group. The teeth were immersed in 3% methylene blue dye solution for 24 h. The samples were split longitudinally and the depth of dye penetration was examined through light microscopy.

RESULTS

No significant statistical differences were found at different retro-preparation lengths (P > 0.05). Differences were found between materials (P > 0.05).

CONCLUSION

Biodentine showed significantly lower ML when compared to Super-EBA and no statistical significative differences were observed when samples were retro-prepared at 3 mm or 9 mm.

A rare mandibular neoplasm: case report of a Central Giant Cell Granuloma

Mandible can be affected by a great variety of neoformations, like aneurysmal bone cyst, odontogenic myxoma, CGCG (Central Giant Cell Granuloma), GCT (giant cell tumor), sarcoma, ameloblastoma, lymphoma, ossifyng fibroma, odontogenic mixoma, granuloma, arteriovenous malformations and Schwannoma. Occasionally is not possible to find clinical or radiological distinctive findings so is usefull to perform additional exams, think about rare disease and perform an explorative surgical treatment which can be adapted to the intraoperatory findings. This attitude may help to reduce overtreatment but also to be radical especially in case of rare condition like the case presented: a Central Giant Cell Granuloma of the jaws. In this case report the authors present a 19-year-old female with a slowly enlarging, painfull swelling on the left side of the lower jaw. Ortopantomography exam revealed an osteolytic bone formation confirmed by Tomographic Dental Scan, MRI and Eco-Doppler exam. No one of these procedures, however, allowed to characterize the neoformation. For that reason was planned immediately an explorative surgical treatment, instead of an agosbiopsy. Macroscopic free margins resection provided radicality on one side and saved much bone tissue as possible on the other; morever it would have permitted to be more demolitive with a further procedure if the histopathological examination of specimen didn't show complete neoformation removal. KEY WORDS: Central Giant Cell Granuloma, Rare Mandibular Neoplasm, Explorative Surgical Treatment.

Dental Caries Occurrence in Inflammatory Bowel Disease Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

The present review aimed to systematically evaluate the occurrence of caries in patients with inflammatory bowel disease (IBD), either Crohn's disease (CD) or ulcerative colitis (UC), compared to healthy controls.

MATERIALS AND METHODS

MEDLINE (PubMed), Embase, Google Scholar, LILACS, and Cochrane Library electronic databases were screened. Caries experience was measured through the Decayed, Missing, Filled Teeth (DMFT) index. The weighted mean difference (WMD) with 95% confidence interval was calculated between IBD patients and healthy controls.

RESULTS

Six studies were selected for the inclusion in the systematic review, 5 of which were also included in the quantitative synthesis of data. The WMD in the DMFT index between IBD and healthy subjects was 3.04 (1.52, 4.56) (p = 0.10). Subgroup analysis showed no difference (p = 0.31) between CD (2.52 [0.54, 4.49]) and UC (4.01 [1.52, 4.56]) subjects.

CONCLUSIONS

There is a remarkably higher past and present occurrence of dental caries in subjects with IBD than healthy controls. This result should encourage clinicians to include oral health preventive programs in the overall treatment plan of IBD patients.

Cyclic fatigue and torsional resistance evaluation of Reciproc R25 instruments after simulated clinical use

BACKGROUND

To assess the influence of multiple uses on the cyclic flexural fatigue and torsional resistance of Reciproc R25 (REC) instruments.

METHODS

256 canals (2 for each mandibular molar) were prepared using Reciproc R25 instruments. A total of 96 25-mm-long Reciproc R25 instruments were divided in six groups (n=8) on the basis of different number of canal shaped: new instruments (control group), 1, 2, 3, 4 or 6 canals shaped during simulated clinical use for other groups respectively. Sixteen files were used for each of the six groups (8 instruments for cyclic fatigue test and 8 ones for torsional test). Times to fracture (TtF) for cyclic fatigue and ultimate torsional strength and angle of rotation to fracture for torsional resistance were recorded. Data were statistically evaluated by the analysis of variance (ANOVA) with P<.05.

RESULTS

As for cyclic fatigue resistance, there was no significant difference between new REC and REC used in one, two and three canals respectively (P>.05). REC used in four and six canals showed significant lower times to fracture when compared with other groups (P<.05) with REC used in six canals showing the significant lowest times to fracture (P<.05). Considering torsional resistance parameters, no significant difference was observed between the new and used instruments (P>.05).

CONCLUSIONS

REC25 files showed a significant decrease in cyclic fatigue resistance only when used in four or more molar canals while their torsional behavior was not affected by multiple uses.

Surface evaluations of a nanocomposite after different finishing and polishing systems for anterior and posterior restorations

This study aims to evaluate the effects of different finishing and polishing (F/P) systems on gloss and surface morphology of a new nanocomposite. Thirty discs of Filtek Universal Restorative material (3 M, ESPE) were prepared and divided into six groups (n = 5). Group A and B followed F/P protocols for anterior restorations, whereas Group C and D for posterior ones. Group E represented the control (covered by Mylar strip) and Group F represented the nanocomposite placement by means of clinical hand instruments; Groups E and F did not undergo F/P procedures. Among the polished groups, Group B showed the highest values (68.54 ± 7.54 GU), followed by Group A and D (46.87 ± 5.52 GU; 53.76 ± 2.65 GU). Finally, Group C (37.38 ± 4.93 GU) displayed the lowest results. Overall, Group E showed the highest gloss values (93.45 ± 8.27 GU), while Group F presented the lowest ones (1.74 ± 0.64 GU). Surface analysis revealed that Group A, C, and D displayed a smooth surface. Group B showed the lowest irregularities. Group E exhibited the most uniform superficial morphology. On the other hand, Group F displayed the most irregular one. In conclusion, using the tested material, only two protocols achieved appropriate gloss values. Then, clinicians might use the protocols of Group B and Group D, for anterior and posterior restorations, respectively.

Root canal debridement by negative pressure irrigation, ultrasonically activated irrigation and their combination

Despite scientific evidence that root canal debridement is the cornerstone for successful treatment, the effectiveness of a combination of delivery and activation systems in cleaning root canals remains unknown. This study is the first to demonstrate the remaining pulp tissue in root canals after irrigation with various techniques such as positive pressure syringe-and-needle irrigation, ultrasonic activation, negative pressure irrigation and ultrasonic activation after negative pressure irrigation. The results showed that negative pressure irrigation alone and its combination with ultrasonic activation resulted in significantly superior effectiveness than positive pressure irrigation and ultrasonic activation alone in the apical-third of root canals.

Immediate and Delayed Bond Strength of a Multimode Adhesive to Deep Coronal Dentin Following Different Root Canal Irrigation Regimens

PURPOSE

To investigate the effects of root canal irrigants, dentin surface treatment, and timing of the restoration on the microtensile bond strength (μTBS) of a universal adhesive to deep coronal dentin.

MATERIALS AND METHODS

Ninety (90) intact molars were grouped according to the irrigation protocol: group 0 (saline, control group); group 1: 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) followed by 5.25% NaOCl; group 2: 18% etidronic acid (HEDP) + 5.25% NaOCl in a single mixture. Groups 1 and 2 were divided into 2 subgroups (n = = 10) according to the time of restoration: immediate (subgroup A) and after 7 days (subgroup B). Four other groups (n = 10) were created according to the dentin surface pretreatment and received an immediate restoration: group 3: 5.25% NaOCl - 17% EDTA and AH Plus Cleaner; group 4: 5.25% NaOCl - 17% EDTA and 100% ethanol; group 5: 5.25% NaOCl + 18% HEDP and AH Plus Cleaner; group 6: 5.25% NaOCl + 18% HEDP and 100% ethanol. μTBS testing was carried out for each subgroup and interfaces were analyzed through SEM. The μTBS was analyzed with Welch statistics and the post-hoc Games-Howell test for multiple comparisons (p < 0.05).

RESULTS

Statistically significant differences were observed between test groups and control groups (p < 0.001), except for group 3 (p = 0.349). No significant differences were recorded between groups 1A (27.5 ± 8.7 MPa), 2A (32.6 ± 14.5 MPa) and 3 (27.3 ± 14.3 MPa). Group 6 (48.6 ± 11.6 MPa) exhibited the highest μTBS among all tested groups. For groups 1 and 2, significantly higher values were recorded for subgroups 1B (39.3 ± 7.6 MPa) and 2B (43.8 ± 8.3 MPa) compared to subgroups 1A (27.5 ± 8.7 MPa) and 2A (32.6 ± 14.5 MPa).

CONCLUSION

When using NaOCl as root canal irrigant, it is advisable to delay the placement of a post-endodontic-treatment restoration.

Influence of remaining tooth substance and post-endodontic restoration on fracture strength of endodontically treated maxillary incisors

The aim is to evaluate the influence of remaining tooth substance and post-endodontic restoration on fracture strength of endodontically treated maxillary incisors. 150 maxillary central incisors were divided into three groups, Group 0, intact teeth; Group 1, removal of distal wall; Group 2, removal of mesial and distal walls, and further into two subgroups A₀,A₁,A₂ and B₀,B₁,B₂ according to post-endodontic restoration (post/no-post), then loaded to fracture. Interactions among variables and intergroup significance were tested with two-way ANOVA and Kruskal Wallis's tests (p≤0.05). Tukey's test was applied for multiple comparisons. Statistically significant differences were found between groups B₁-A₁, and B₂-A₂, but they were not found between B₀-A₀. Intragroup analysis showed statistically significant differences in both groups post/no-post with decreasing dental substance. Fiber post placement causes an increase in fracture strength and a reduction of irreparable fractures in endodontically treated maxillary central incisors that lost at least one wall.

Influence of single post, oval, and multi-post restorative techniques and amount of residual tooth substance on fracture strength of endodontically treated maxillary premolars

PURPOSE

The aim of this study was to compare the influence of the number of coronal walls and post-endodontic restorations on the mechanical strength of 165 recently extracted endodontically treated maxillary premolars.

METHODS

The teeth were divided into 3 control (no post) and 3 test groups according to the number of residual walls. Each test group was divided into subgroups according to the type of post-endodontic restoration (single, oval, and multi-post techniques). Samples were prepared conforming to the assigned subgroup. A universal loading machine applied a load parallel to the longitudinal axis of the teeth, thus simulating physiological occlusion. ANOVA and the Kruskal Wallis test were used for comparisons (P ≤ 0.05), and Tukey's test for multiple comparisons.

RESULTS

For intact teeth, significant differences were found among all 3 subgroups, with single post showing the highest values. For 3 residual walls, oval post resulted in significantly lower values than single and multi-post systems. For 2 residual walls, the multi-post technique showed almost twice the resistance of oval post restorations.

CONCLUSION

In oval canals the use of a single or multi-post technique increased post-and-core resistance even in intact teeth, whereas oval fiber posts showed no improvements. Multi-post design improved fracture resistance mostly in maxillary premolars lacking both marginal ridges.

Different Post Placement Strategies for the Restoration of Endodontically Treated Maxillary Premolars with Two Roots: Single Post vs Double Post

AIM AND OBJECTIVE

The present study compared the fracture strength and failure pattern of endodontically treated, bi-rooted, maxillary premolars with different number of coronal walls and postendodontic restoration (one vs double post).

MATERIALS AND METHODS

105 premolars were divided into 3 groups according to the number of residual walls: control group (intact teeth; n = 15), group 1 (3 residual walls; n = 45), group 2 (2 residual walls; n = 45). Each test group was then divided into 3 subgroups (n = 15 each) according to postendodontic restoration: no post (A), 1 post (B) or 2 posts (C). A load was applied parallel to the longitudinal axis of the teeth, thus simulating physiological occlusion. ANOVA and Tukey's tests were used to detect fracture strength differences among groups, while Chi-square test was used to check differences in fracture pattern.

RESULTS

No significant differences were observed between control group (intact teeth) and groups A1 (p = 0.999), B1 (p = 0.997) and C1 (p = 1.000); statistically significant differences were detected between control group and groups A2 (p < 0.001), B2 (p < 0.001) and C2 (p < 0.05). Different post placement techniques were non-significantly associated with fracture pattern in both groups 1 (p = 0.666) and 2 (p = 0.143) while, irrespective of the number of posts, the presence of the post was significantly associated with the fracture pattern in teeth with two residual walls. The double-post technique did not further improve the fracture resistance of hardly damaged endodontically treated maxillary bi-rooted premolars compared to single-post technique. Therefore, the insertion of a single post in the palatal canal could be a safer and more conservative choice.

CLINICAL SIGNIFICANCE

The double-post technique did not further improve the fracture resistance of severely structurally compromised endodontically treated maxillary premolars with two roots compared to the single-post technique. Therefore, the safer and less invasive treatment is the placement of a single post in the palatal canal.

A new framework to identify dental emergencies in the COVID-19 era

In order to reduce the spread of COVID-19 (Coronavirus Disease 2019), it is crucial to take extraordinary prevention and safety measures in dental offices, and to defer all elective and non-urgent procedures. Dental emergencies are defined through oral symptoms but, the systemic and psychological conditions of each patient should be considered. The present short communication proposes a multilevel evaluation (oral, systemic and psychological) and risk assessment score for the management of dental emergencies following the SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2) outbreak. A comprehensive categorization and score scale assessment for dental emergencies allows a better identification of patient's treatment needs and avoids unnecessary contact between dental health care providers and patients during the SARS-CoV-2 pandemic.

Push-out Bond Strength of Fiber Posts Cemented Using New Universal Adhesives on Etched and Nonetched Intraradicular Dentin

AIM

The aim of this study was to assess if the curing mode and the etching mode could affect the push-out bond strength of different post cementation systems using two universal adhesives.

MATERIALS AND METHODS

A total of 100 single-rooted teeth were divided into Prime & Bond Elect (PBE), Prime & Bond Active (PBA), and Prime & Bond XP (PBXP) as a control. The PBE, PBA, and PBXP were used in the self-etch (SE) and etch and rinse (E&R) mode. Post cementation was performed using Core X flow used in dark-cure and in light-cure. Data were analyzed using the one-way ANOVA test and post hoc Bonferroni and Dunnet tests. The Student's t test was performed to find significance between two independent groups.

RESULTS

Bond strength was significantly influenced by the adhesive strategies. The PBE and PBA obtained higher values when used in the SE mode (p < 0.001). Light-cured groups obtained significantly higher values (p < 0.001) compared to dark-cured groups. The post space region also had a significant effect on the bond strength; the apical third recorded lower values in all groups (p < 0.001).

CONCLUSION

The PBA and PBE universal adhesives obtained higher PBS values when used in the SE mode and followed by the light-curing of resin cement.

CLINICAL SIGNIFICANCE

Universal adhesives represent a good alternative to the conventional total-etch adhesive system for fiber post cementation. Since they perform better in SE, they would be recommendable in clinical practice, as they can be used with a simplified technique.

A pilot trial on lithium disilicate partial crowns using a novel prosthodontic functional index for teeth (FIT)

Background

Lithium disilicate is now a well accepted material for indirect restorations. The aim of this trial was to evaluate two lithium disilicate systems using a novel prosthodontic Functional Index for Teeth (FIT).

Methods

Partial adhesive crowns on natural abutment posterior teeth were made on sixty patients. Patients were divided into two groups: Group 1 IPS e.max press (Ivoclar-Vivadent, Schaan, Liecthestein), and Group 2 Initial LiSi press (GC Co., Tokyo, Japan). The restorations were followed-up for 3 years, and the FIT evaluation was performed at last recall. The FIT is composed of seven variables (Interproximal, Occlusion, Design, Mucosa, Bone, Biology and Margins), each of them are evaluated using a 0–1-2 scoring scheme, and is investigated by an oral radiograph and occlusal and buccal pictures. More in details, three variables have the three scores made on the presence or not of major, minor or no discrepancy (for ‘Interproximal’, ‘Occlusion’ and ‘Design’), presence or not of keratinized and attached gingiva (‘Mucosa’), presence of bone loss > 1.5 mm, < 1.5 mm or not detectable (‘Bone’), presence or not of Bleeding on Probing and or Plaque Index (‘Biology’), presence of detectable gap and marginal stain or not (‘Margins’). The Mann-Whitney ‘U’ test was used and the level of significance was set at p < 0.05. Also, “success” of the crowns (restoration in place without any biological or technical complication) and “survival” (restoration still in place with biological or technical complication) were evaluated.

Results

Regarding FIT scores, all partial crowns showed a stable level of the alveolar crest without detectable signs of bone loss in the radiographic analysis. All other evaluated parameters showed a high score, between 1.73 and 2. No statistically significant difference emerged between the two groups in any of the assessed variables (p > 0.05). All FIT scores were compatible with the outcome of clinical success and no one restoration was replaced or repaired and the success rate was 100%.

Conclusions

The results showed that it is possible to evaluate the clinical performance of partial crowns using FIT. The FIT proved to be an effective tool to monitor the performance of the restorations and their compatibility with periodontal tissues at the recall. The FIT can be really helpful for a standardized evaluation of the quality of the therapy in prosthodontic dentistry. The two lithium disilicate materials showed similar results after 3 years of clinical service.

Trial registration

The study protocol was approved by the Ethical Committee of University of Siena (clinicaltrial.gov # NCT 01835821), ‘retrospectively registered’.

The Effect of Zinc Lactate added Tablets on Volatile Sulfur-containing Compounds in the Oral Cavity

Background:

Oral malodor is defined as breath that is offensive to others and its prevalence is around 35%.

Objective:

A controlled clinical double-blinded study was conducted to assess the efficacy of sugar-free tablets containing zinc lactate on oral Volatile Sulfur-containing Compounds (VSC) versus placebo tablets.

Methods:

All participants, who met the inclusion criteria, had to score a level of VSC ≥75 ppb at the basal measurement. Subjects were randomly assigned to one of the groups. The test tablet (0.7g) contained 0.255 mg of zinc lactate; the control tablet was identical but without the active agent. The OralChroma2© device was utilized to evaluate VSC. The levels were recorded at baseline, after sucking two tablets in succession and after 1 hour and 2 hours. Data were analyzed with SPSS and significance was set at α=0.05.

Results:

186 subjects completed the trial. The mean reduction from baseline at the end of tablets sucking was, respectively, 43% (p <0.001) in the control and 67% (p <0.001) in the test group, after 1 hour, it was 6% in the control (p=NS) and 25% (p <0.001) in the test group, after 2 hours, it was 3% in the control (p=NS) and 12% (p <0.001) in the test group. The comparison between the two groups after baseline adjustment showed a statistically significant difference for reductions at the end of the sucking period (p <0.001), after 1 hour (p <0.001) and after 2 hours (p <0.05).

Conclusion:

Tablets containing zinc lactate can statistically reduce the oral VSC levels immediately and for over 2 hours.

Evidence-based treatment planning for the restoration of endodontically treated single teeth: importance of coronal seal, post vs no post, and indirect vs direct restoration

Every orthograde endodontic procedure requires restoration of the coronal (access) cavity. The specific type of treatment used in individual cases greatly depends on the amount and configuration of the residual coronal tooth structure. In practice there are Class I access cavities as well as coronally severely damaged, even decapitated, teeth and all conceivable manifestations in between. The latest attempts to review results from clinical trials to answer the question of whether post placement or crowning can be recommended for the restoration of endodontically treated teeth or not are inconclusive. For dental practitioners, this is not a satisfactory result. This appraisal evaluates available evidence and trends for coronal restoration of single endodontically treated teeth with a focus on clinical investigations, where available. It provides specific recommendations for their coronal restoration to assist clinicians in their decision making and treatment planning.

Effect of four different finishing and polishing systems on resin composites: roughness surface and gloss retention evaluations

BACKGROUND

Finishing and polishing procedures play a crucial role to achieve the best aesthetic result of direct restorations. Many manufacturers to the clinicians offer different finishing and polishing systems. This study aims to examine the behavior of four different finishing and polishing systems on the roughness, gloss and morphology surface of one resin composite.

METHODS

Twelve Filtek XTE Supreme (3M ESPE) discs were prepared and divided into 4 groups (N.=3), depending on the different finishing and polishing systems: Group 1 (GP1) Sof-Lex Extra-Thin XT discs; Group 2 (GP2) Sof-Lex Coarse black disc, multi-fluted bur, Sof-Lex Diamond Polishing System Spirals; Group 3 (GP3) Sof-Lex Coarse black disc, multi-fluted bur, Sof-Lex Diamond Polishing System Spirals, Diamond Twist SCL; Group 4 (GP4) with Sof-Lex Coarse black disc, multi-fluted bur and Occlubrush. The roughness and gloss were evaluated and then samples examined by Scanning Electron Microscopy (SEM) to analyse the morphology after finishing and polishing.

RESULTS

Regarding the surface roughness, GP1 and GP2 showed similar values for Ra, Ry, Rz and Rq parameters; while GP3 displayed the lowest values in all parameters; GP4 had the highest Ra value. Regarding the gloss, the values decreased as follows: GP3>GP2=GP4>GP1 (P<0.05). Scanning electron micrographs showed the abrasion of the samples with an increase in the surface roughness in GP1 and GP4. One-way ANOVA followed by Tukey's Test was used for statistical evaluations (P<0.05).

CONCLUSIONS

The roughness and gloss surface of resin composites depend on the finishing and polishing systems used. This study demonstrates that satisfactory gloss outcomes are obtained using a system based on diamond paste.

Antimicrobial efficacy of cordless sonic or ultrasonic devices on Enterococcus faecalis-infected root canals

AIM

The aim of the present study was to evaluate the immediate and residual antimicrobial activity of cordless sonic or ultrasonic devices on Enterococcus faecalis (E faecalis)-infected teeth.

METHODS

A total of 140 single-rooted extracted teeth with E faecalis were grouped as follows (N = 15): conventional syringe irrigation with 3% sodium hypochlorite activated by ultrasonic device (group 1) or cordless ultrasonic device (group 2), EndoActivator (group 3) or without activation (group 4), conventional syringe irrigation with sterile bi-distilled water and ultrasonic device (group 5), EndoUltra (group 6), EndoActivator (group 7), or without activation (group 8). The remaining 20 teeth were used for positive and negative controls. Colony-forming units (CFU) and turbidity were recorded from bacteriological samples taken before and after irrigation and after 24 hours of re-incubation. Data were statistically analyzed using Student's t test, Mann-Whitney test, Kruskal-Wallis test, and Dunn's multiple comparison tests (P < .05).

RESULTS

Groups 1 and 2 showed higher antimicrobial efficacy than groups 3 and 4 (P < .05). No bacteria reduction was found in groups 5-8 (P > .05). After 24 hours, regrowth of bacteria was not significantly different for all groups (P > .05).

CONCLUSIONS

Ultrasound produced lower CFU and turbidity after treatment and after re-incubation of 24 hours than sonic or no activation.

Shaping effectiveness and surface topography of reciprocating files after multiple simulated uses

This in vitro study assessed morphological changes and efficiency of reciprocating files after multiple uses. Sixty standardized Endo Training Blocks and 10 ReciprocR25 files were selected (six blocks for each file). Each file was its own control (before use vs. after each instrumentation). The instruments were used according to the manufacturer's instructions, and scanning electron microscopy was used to observe fatigue cracks, metal strips/metal flash, pitting, fretting, debris, disruption of the cutting edge, and plastic deformations after each instrumentation. The presence of seven wear variables was scored semiquantitatively by viewing micrographs collected before and after use. The prepared areas in resin blocks were calculated and compared by using AutoCAD software. The control group had significantly lower values for all wear variables except fretting and plastic deformation. The presence of fatigue cracks and metal strips/metal flash significantly differed between unused instruments and instruments used four or five times, in all observed sections. The area of instrumented Endo Training Blocks significantly differed in relation to the number of instrument uses. The Reciproc files wore progressively, and repeated use affected their shaping efficiency in simulated canals.

Influence of proper or reciprocating optimum torque reverse kinematics on cyclic fatigue of four single files

AIM

The aim of the present study was to evaluate the resistance to cyclic fatigue of heat-treated single files used in proper or in reciprocating optimum torque reverse motions.

METHODS

Ninety-six HyFlex electrical discharge machining (EDM), Reciproc R25 (Rec), WaveOne Primary (WO), and WaveOne Gold (WOG) Primary were used. Resistance to cyclic fatigue was determined by recording time to fracture in a stainless steel artificial canal. Differential scanning calorimetric analysis was performed. Data were analyzed by two-way analysis of variance and Bonferroni post-hoc tests at 0.05.

RESULTS

In both movements, HyFlex EDM showed higher time to fracture than other files (P < 0.0001). Rec showed higher time to fracture than WO (P < 0.0001), while WOG showed higher cyclic fatigue resistance than Rec and WO with both movements (P < 0.005).

CONCLUSIONS

Reciprocating optimum torque reverse motion improved significantly cyclic fatigue resistance of gold and controlled memory wire single files.

Crossover Clinical Trial of Tablets Containing Sodium Tripolyphosphate on Dental Stain Formation

OBJECTIVES

The purpose of this clinical investigation was to evaluate the effectiveness of sugar-free tablets containing sodium tripolyphosphate 2% or sodium tripolyphosphate 0.65%, compared to a no-tablet control in preventing the formation of extrinsic stains over a 12- week period of regular unsupervised use preserving daily oral hygiene with dentifrice and usual tooth brushing.

METHODS

This was a single-center, examiner-blind, randomized, 12-week crossover clinical trial. Sixty-six adult participants were enrolled in the study and were submitted to a professional cleaning to have a stain-free baseline. They either consumed two sugar-free tablets four times per day or not for 12 weeks. At the crossover, all procedures were repeated and subjects were assigned to another group. Extrinsic stain was measured at each 12-week period by the Modified Lobene Stain Index (MLSI).

RESULTS

After the three legs of 12 weeks, 60 subjects completed the trial, their MLSI stain scores showed a significant 35.5% reduction (p < 0.001) in new stain formation for those using the sodium tripolyphosphate 2% tablets, and a significant 23.3% reduction (p < 0.001) in new stain formation for those using the sodium tripolyphosphate 0.65% tablets versus the control group.

CONCLUSIONS

This clinical study showed that regular use of sugar-free tablets added with sodium tripolyphosphate 2% or 0.65% can reduce stain formation on the anterior teeth respectively by 35.5% (p < 0.001) or 23.3% (p < 0.001), both on facial and lingual/palatal surfaces.

Effects of scanning technique on in vitro performance of CAD/CAM-fabricated fiber posts

This study assessed push-out strength, cement layer thickness, and interfacial nanoleakage of luted fiber posts fabricated with computer-aided design/computer-assisted manufacture (CAD/CAM) technology after use of 1 of 3 scanning techniques, namely, direct scanning of the post space (DS), scanning of a polyether impression of the post space (IS), and scanning of a plaster model of the post space (MS). Thirty premolars were randomly assigned to three groups corresponding to the scanning technique. Posts were computer-designed and milled from experimental fiber-reinforced composite blocks. The mean (±SD) values for push-out strength and cement thickness were 17.1 ± 7.7 MPa and 162 ± 24 μm, respectively, for DS, 10.7 ± 4.6 MPa and 187 ± 50 μm for IS, and 12.0 ± 7.2 MPa and 258 ± 78 μm for MS specimens. Median (interquartile range) interfacial nanoleakage scores were 3 (2-4) for DS, 2.5 (2-4) for IS, and 3 (2-4) for MS. Post retention was better for fiber posts fabricated by DS technique than for those fabricated by IS and MS. Cement thickness did not differ between DS and IS specimens, but the cement layer was significantly thicker in the MS group than in the other two groups. Scanning technique did not affect sealing ability, as the three groups had comparable nanoleakage values.

Marginal sealing of relocated cervical margins of mesio-occluso-distal overlays

We investigated the effect of cervical marginal relocation (CMR) on marginal sealing with two different viscosity resin composites, before adhesive cementation of composite computer-aided design/computer-assisted manufacture mesio-occluso-distal (MOD) overlays. Standardized MOD cavities prepared in 39 human molars were randomly assigned to three groups. The proximal margins on the mesial side were located 1 mm below the cementoenamel junction. On the distal side of the tooth, the margins were located 1 mm above the cementoenamel junction. In Groups 1 and 2, mesial proximal boxes were elevated with a hybrid composite (GC Essentia MD) and a flowable composite (GC G-ænial Universal Flo), respectively. CMR was not performed in Group 3. The overlays were adhesively cemented, and interfacial leakage was quantified by scoring the depth of silver nitrate penetration along the adhesive interfaces. Leakage score at the dentin-CMR composite interface did not significantly differ between the two tested composites but was significantly lower for Group 3. In all groups, scores were significantly higher at the dentin interface than at the enamel interface. These results indicate that the performance of flowable and microhybrid resin composites, as indicated by marginal sealing ability, is comparable for CMR.

Evolution of Nickel-titanium Alloys in Endodontics

To improve clinical use of nickel-titanium (NiTi) endodontic rotary instruments by better understanding the alloys that compose them. A large number of engine-driven NiTi shaping instruments already exists on the market and newer generations are being introduced regularly. While emphasis is being put on design and technique, manufacturers are more discreet about alloy characteristics that dictate instrument behavior. Along with design and technique, alloy characteristics of endodontic instruments is one of the main variables affecting clinical performance. Modification in NiTi alloys is numerous and may yield improvements, but also drawbacks. Martensitic instruments seem to display better cyclic fatigue properties at the expense of surface hardness, prompting the need for surface treatments. On the contrary, such surface treatments may improve cutting efficiency but are detrimental to the gain in cyclic fatigue resistance. Although the design of the instrument is vital, it should in no way cloud the importance of the properties of the alloy and how they influence the clinical behavior of NiTi instruments.

CLINICAL SIGNIFICANCE

Dentists are mostly clinicians rather than engineers. With the advances in instrumentation design and alloys, they have an obligation to deal more intimately with engineering consideration to not only take advantage of their possibilities but also acknowledge their limitations.

Performance of CAD/CAM fabricated fiber posts in oval-shaped root canals: An in vitro study

PURPOSE

To assess the push-out strength, the cement layer thickness and the interfacial nanoleakage of prefabricated fiber posts, CAD/CAM fiber posts and metal cast posts cemented into oval-shaped root canals.

METHODS

Oval-shaped post spaces were prepared in 30 single-rooted premolars. Roots were randomly assigned to three groups (n=10), according to the post type to be inserted: Group 1: Prefabricated fiber post (D.T. Light-Post X-RO Illusion); Group 2: Cast metal post; Group 3: CAD/CAM-fabricated fiber post (experimental fiber blocks). In Group 3, post spaces were sprayed with scan powder (VITA), scanned with an inEos 4.2 scanner, and fiber posts were milled using an inLab MC XL CAD/CAM milling unit. All posts were cemented using Gradia Core dual-cure resin cement in combination with Gradia core self-etching bond (GC). After 24 hours, the specimens were sectioned perpendicular to the long axis into six 1 mm-thick sections, which were differentiated by the root level. Sections from six roots per group were used to measure the cement thickness and subsequently for the thin-slice push-out test, whereas the sections from the remaining four teeth were assigned to interfacial nanoleakage test. The cement thickness around the posts was measured in micrometers (µm) on the digital images acquired with a digital microscope using the Digimizer software. Thin-slice push-out test was conducted using a universal testing machine at the crosshead speed of 0.5 mm/minute and the bond strength was expressed in megaPascals (MPa). The interfacial nanoleakage was observed under light microscope and quantified by scoring the depth of silver nitrate penetration along the post-cement-dentin interfaces. The obtained results were statistically analyzed by Kruskal-Wallis ANOVA, followed by the Dunn's Multiple Range test for post hoc comparisons. The level of significance was set at P< 0.05.

RESULTS

Statistically significant differences were found among the groups in push-out bond strength, cement thickness and interfacial nanoleakage (P< 0.05). CAD/CAM-fabricated fiber posts achieved retention that was comparable to that of cast metal posts and significantly higher than that of prefabricated fiber posts. The cement layer thickness around CAD/CAM-fabricated fiber posts was significantly lower than around prefabricated fiber posts, but higher than that around cast metal posts. Root level was not a significant factor for push-out strength in any of the groups, whereas it significantly affected cement layer thickness only in the prefabricated fiber post group. No differences were observed in interfacial nanoleakage between CAD/CAM fabricated and prefabricated fiber posts, while nanoleakage recorded in cast metal posts was significantly lower.

CLINICAL SIGNIFICANCE

CAD/CAM fabricated fiber posts could represent a valid alternative to traditionally used posts in the restoration of endodontically-treated teeth with oval or wide root canals, offering the advantages of better esthetics, retention, and cement thickness values that are comparable to cast post and cores.

Use of bioactive materials and limited FOV CBCT in the treatment of a replanted permanent tooth affected by inflammatory external root resorption: a case report

BACKGROUND

Inflammatory external root resorption is one of the possible complications of replantation of an avulsed tooth. Several studies have shown that limited FOV CBCT is an efficient diagnostic support and in treatment planning of these cases in paediatric patients because of its high resolution combined with low radiation doses. The recent literature has suggested that Biodentine is an effective material for resolution of inflammatory root resorption.

CASE REPORT

This article describes the successful therapy of a replanted tooth affected by inflammatory root resorption. In the present case, a CBCT exam was performed to detect the extent of the damage, and the canal was filled with Biodentine in the apical third. At present, the threated tooth is asymptomatic, and the twelve months follow-up examination showed healing of periradicular hard tissues.