Industrial noise: A new stimulus for dental pulp aging? Qualitative and quantitative analysis in Wistar rat teeth-A pilot study.

Morphological changes induced by industrial noise have been experimentally observed in several organs. This study aims to characterize the effect of industrial noise on the pulp cell density of Wistar rats from a histological point of view, through qualitative and quantitative analysis. The histologic sections were observed over the optical microscope and photographed using 10x and 40x magnifications and analyzed using an image processing software. They refer to a group of animals exposed to industrial noise for 3 months and for 7 months (EG) and another group of animals kept in silence for control (CG) during the same periods. There was a significant decrease in pulp cell density in teeth of the animals exposed for 3 months when compared to control teeth group (p = 0.01). However, in the group exposed for 7 months, no statistically significant differences were found (p = 0.66). Even so, we found an evident relationship between exposure to industrial noise and teeth morphological changes. The observed changes are similar to the modifications found on aged teeth. Therefore, this study places industrial noise as an aggressive stimulus that can cause a reaction of the pulp-dentin complex with morphological changes compatible with premature aging of the tooth.

Perceived xerostomia, stress and periodontal status impact on elderly oral health-related quality of life: findings from a cross-sectional survey.

BACKGROUND: To investigate if self-perceived xerostomia and stress are significant variables on the Oral-Health Related Quality of Life (OHRQoL) of elderly patients, considering the periodontal status, oral hygiene habits and sociodemographic characteristics simultaneously. METHODS: The study cohort included 592 participants (320 females/272 Males), aged 65 years or older, representing the elder inhabitants of the Study of Periodontal Health in Almada-Seixal (SoPHiAS). Patients answered a socio-demographic and oral hygiene habits questionnaire. The Oral Health Impact Profile-14 (OHIP-14), Summated Xerostomia Inventory-5 (SXI-5) and Perceived Stress Scale-10 (PSS-10) were used. Full-mouth circumferential periodontal inspection was carried out. Multivariable regression analyses were used considering the level of periodontitis, clinical characteristics, the number of teeth, SXI, PSS-10, age, gender and oral hygiene habits. RESULTS: Self-perceived xerostomia and stress showed a positive significant correlation with OHRQoL and each of its domains. Multiple linear regression analysis demonstrated the significant impact of SXI-5 (B = 1.20, p <  0.001) and PSS-10 (B = 0.35, p <  0.001) on the OHRQoL. SXI-5 (Odds Ratio (OR) = 1.28, p <  0.001) and PSS-10 (OR = 1.03, p = 0.022) were associated with a more frequently affected OHRQoL. The number of missing teeth, being male, mean probing depth and mean clinical attachment loss were also significant towards a frequently affected OHRQoL. Conversely, age was negatively associated with a lower OHRQoL. CONCLUSION: Self-perceived xerostomia and stress are significant variables towards OHRQoL in elderly patients. Future studies should consider these self-perceived xerostomia and stress when investigating the impact of periodontitis and missing teeth on quality of life of older adults.

Relationship between self-reported bruxism and periodontal status: Findings from a cross-sectional study.

BACKGROUND: Several studies seek to prove the relationship between bruxism and periodontal status although it remains unclear and debatable. We aimed to assess the association between self-reported (SR) bruxism with the periodontal status in a large scale survey. METHODS: A total of 1064 individuals from the southern region of the Lisbon Metropolitan Area (Portugal) were enrolled. Patients were interviewed for the SR bruxism assessment through a self-report questionnaire. Full-mouth periodontal status was assessed with probing depth (PD), clinical attachment loss (CAL), gingival recession (REC), and bleeding on probing (BoP) being measured. The American Association of Periodontology/European Federation of Periodontology 2018 case definitions were used. Logistic regression analyses provided information on the influence of SR bruxism towards periodontitis. RESULTS: SR bruxers exhibited lower prevalence of periodontitis. Additionally, SR bruxers with periodontitis had PD and CAL significantly lower than patients with only periodontitis. Multivariate analysis suggests that SR bruxism was significantly associated with a lower risk of periodontitis (odds ratio [OR] = 0.42 95% CI: 0.32-0.56). Mean PD and CAL were significantly lower in SR bruxers. When assessing the type of SR bruxism, significant differences among mean PD, CAL, and BoP levels were also identified. CONCLUSION: SR bruxism and periodontal status are negatively associated. SR bruxers exhibit lower odds towards periodontitis and better periodontal clinical characteristics. Further studies are mandatory to clarify these findings.

Study of Periodontal Health in Almada-Seixal (SoPHiAS): a cross-sectional study in the Lisbon Metropolitan Area.

This study aimed to describe the prevalence and extent of periodontal diseases among adults in the southern region of the Lisbon Metropolitan Area. This population-based cross-sectional study included 1,064 randomized participants (aged 18 to 95 years, 617 females/447 males). Sociodemographic, behaviours and medical information were recorded. Periodontal conditions were assessed with a full-mouth circumferential periodontal examination. It was used the American Association of Periodontology/European Federation of Periodontology 2017 case definitions. A logistic regression analysis was applied to ascertain hypothetical risk factors towards periodontitis. The prevalence of periodontitis was 59.9%, with 24.0% and 22.2% of the participants exhibiting severe and moderate periodontitis, respectively. The risk of periodontitis significantly increased with age (OR = 1.05, 95% CI: 1.04-1.06), for active and former smokers (OR = 3.76 and OR = 2.11, respectively), with lower education levels (OR = 2.08, OR = 1.86, for middle and elementary education, respectively) and with diabetes mellitus (OR = 1.53). This study confirms a high burden of periodontitis in the target (Portuguese) sub-population. The findings provide a comprehensive understanding that will empower appropriate national public oral health programmes and population-based preventive actions.

Fine-tuning multilevel modeling of risk factors associated with nonsurgical periodontal treatment outcome.

This retrospective study evaluated the influence of known risk factors on nonsurgical periodontal treatment (NSPT) response using a pocket depth fine-tuning multilevel linear model (MLM). Overall, 37 patients (24 males and 13 females) with moderate-to-severe chronic periodontitis underwent NSPT. Follow-up visits at 3, 6, and 12 months included measurements of several clinical periodontal parameters. Data were sourced from a previously reported database. In a total of 1416 initially affected sites (baseline PD ≥ 4 mm) on 536 teeth, probing depth (PD) and clinical attachment loss (CAL) reductions after NSPT were evaluated against known risk factors at 3 hierarchical levels (patient, tooth, and site). For each post-treatment follow-up, the variance component models fitted to evaluate the 3-level variance of PD and CAL decrease revealed that all levels contributed significantly to the overall variance (p < 0.001). Patients who underwent NSPT and were continually monitored had curative results. All 3 hierarchical levels included risk factors influencing the degree of PD and CAL reduction. Specifically, the type of tooth, surfaces involved, and tooth mobility site-level risk factors had the strongest impact on these reductions and were highly relevant for the success of NSPT.

Psychometric properties of the Brief Illness Perception Questionnaire (Brief-IPQ) in periodontal diseases.

AIM: To investigate the psychometric properties of the validated Portuguese version of the Brief Illness Perception Questionnaire (Brief-IPQ) in patients with gingivitis and periodontitis. MATERIAL AND METHODS: This study enrolled 571 patients with periodontal diseases (PDs) (67 gingivitis and 504 periodontitis cases), in a population-based epidemiologic survey conducted at the health centres in the South Lisbon Metropolitan Area. Brief-IPQ, a 9-item self-reported scale, reliability was evaluated using Cronbach's alpha. Confirmatory factor analysis (CFA) was used to construct validation. Multigroup analysis tested invariance across gender. RESULTS: The Brief-IPQ showed acceptable reliability (α = .80). Confirmatory factor analysis revealed good model fit (χ2 (16) = 41.236, GFI = 0.982, CFI = 0.985, RMSEA = 0.053). All factors loaded similarly to the original Brief-IPQ scale, with the exception of the "personal control" domain. Periodontal patients downgrade its illness and likely impact. The "consequences" domain showed significant positive correlations with all factors, except "treatment control" and "understanding" domains. The "concern" and "emotional response" domains had the highest significant correlation. Multigroup analysis findings supported factor invariance across the sex groups. CONCLUSION: The Brief-IPQ revealed acceptable reliability, construct factorial validity and invariance across gender. This short instrument may be used as an easily applicable and valuable tool to determine illness perception in patients with PDs.

Fine-tuning multilevel modeling of risk factors associated with nonsurgical periodontal treatment outcome

Abstract This retrospective study evaluated the influence of known risk factors on nonsurgical periodontal treatment (NSPT) response using a pocket depth fine-tuning multilevel linear model (MLM). Overall, 37 patients (24 males and 13 females) with moderate-to-severe chronic periodontitis underwent NSPT. Follow-up visits at 3, 6, and 12 months included measurements of several clinical periodontal parameters. Data were sourced from a previously reported database. In a total of 1416 initially affected sites (baseline PD ≥ 4 mm) on 536 teeth, probing depth (PD) and clinical attachment loss (CAL) reductions after NSPT were evaluated against known risk factors at 3 hierarchical levels (patient, tooth, and site). For each post-treatment follow-up, the variance component models fitted to evaluate the 3-level variance of PD and CAL decrease revealed that all levels contributed significantly to the overall variance (p < 0.001). Patients who underwent NSPT and were continually monitored had curative results. All 3 hierarchical levels included risk factors influencing the degree of PD and CAL reduction. Specifically, the type of tooth, surfaces involved, and tooth mobility site-level risk factors had the strongest impact on these reductions and were highly relevant for the success of NSPT.

Stress, salivary cortisol and periodontitis: A systematic review and meta-analysis of observational studies.

OBJECTIVE: This meta-analysis aims to systematically assess whether periodontitis has a meaningful effect on salivary cortisol, reflecting changes on free blood cortisol levels. DESIGN: The Cochrane Handbook and the PRISMA statement were used as reporting guidelines. The MEDLINE-PubMed, Google Scholar, EMBASE, and CENTRAL databases were searched until September 2017 to identify eligible studies, screened by seven independent authors and verified by an eighth. Studies comparing salivary cortisol level of periodontitis cases to controls were included. Data were extracted using a predefined table and since all papers were non-randomized clinical trials they were appraised using Downs and Black tool. DerSimonian random effects meta-analysis was performed using OpenMetaAnalyst. RESULTS: Six cross-sectional studies were included, with 258 participants with chronic periodontitis and 72 with aggressive periodontitis, in a total of 573 participants. Overall results showed that aggressive periodontitis patients have, on average, 53% higher salivary cortisol levels than healthy controls 1.53 (1.11-2.12). Meta-regression exploring the relationship among salivary cortisol levels and periodontal measures, i.e., periodontitis severity, showed a global neutral effect, although this result requires future confirmation due to the low power of the model. CONCLUSION: Observational studies results suggest that subjects with aggressive periodontitis have higher salivary cortisol levels than healthy ones or patients with chronic periodontitis. Such salivary cortisol response difference may have a negative impact on the periodontium, contributing to worse the burden of aggressive periodontitis disease. In the future, wide and well-designed longitudinal studies should be carried out in order to extensively confirm this possible effect, considering the complex nature of periodontitis and its many confounders factors that may contribute to this outcome.

Prevalence and extent of chronic periodontitis and its risk factors in a Portuguese subpopulation: a retrospective cross-sectional study and analysis of Clinical Attachment Loss.

OBJECTIVES: To assess the prevalence and extent of chronic periodontitis, and its risk factors in a Portuguese subpopulation referred to periodontal examination. METHODS: This retrospective cross-sectional study used a subset of data from patients who sought dental treatment in a university dental clinic in the Lisbon metropolitan area. The sample consisted of 405 individuals (225 females/180 males), aged 20-90 years. All patients underwent a full-mouth periodontal examination and chronic periodontitis was defined as Clinical Attachment Loss (CAL) ≥ 3 mm affecting two or more teeth. Aggressive periodontitis cases were excluded from the analysis. RESULTS: Prevalence of chronic periodontitis was 83.5% (95% CI [80.4-86.6%]). For these subjects, CAL ≥ 3 mm affected 86.0% (95% CI [84.7-87.2]) of sites and 83.7% (95% CI [81.7-85.6]) of teeth, respectively. Mean CAL ranged from 3.6 to 4.3 mm, according to age. In the multivariate logistic regression model, smoking (OR = 3.55, 95% CI [1.80-7.02]) and older age (OR = 8.70, 95% CI [3.66-20.69] and OR = 4.85, 95% CI [2.57-9.16]), for 65+ and 45-64 years old, respectively, were identified as risk indicators for CAL ≥ 3 mm. CONCLUSIONS: This particular Portuguese adult subpopulation had a high prevalence of chronic periodontitis, with severe and generalized clinical attachment loss, and its presence was significantly associated with age and smoking. This data should serve to prepare future detailed epidemiological studies and appropriate public health programs.

Dental stem cells: recent progresses in tissue engineering and regenerative medicine.

Since the disclosure of adult mesenchymal stem cells (MSCs), there have been an intense investigation on the characteristics of these cells and their potentialities. Dental stem cells (DSCs) are MSC-like populations with self-renewal capacity and multidifferentiation potential. Currently, there are five main DSCs, dental pulp stem cells (DPSCs), stem cells from exfoliated deciduous teeth (SHED), stem cells from apical papilla (SCAP), periodontal ligament stem cells (PDLSCs) and dental follicle precursor cells (DFPCs). These cells are extremely accessible, prevail during all life and own an amazing multipotency. In the past decade, DPSCs and SHED have been thoroughly studied in regenerative medicine and tissue engineering as autologous stem cells therapies and have shown amazing therapeutic abilities in oro-facial, neurologic, corneal, cardiovascular, hepatic, diabetic, renal, muscular dystrophy and auto-immune conditions, in both animal and human models, and most recently some of them in human clinical trials. In this review, we focus the characteristics, the multiple roles of DSCs and its potential translation to clinical settings. These new insights of the apparently regenerative aptitude of these DSCs seems quite promising to investigate these cells abilities in a wide variety of pathologies. Key messages Dental stem cells (DSCs) have a remarkable self-renewal capacity and multidifferentiation potential; DSCs are extremely accessible and prevail during all life; DSCs, as stem cells therapies, have shown amazing therapeutic abilities in oro-facial, neurologic, corneal, cardiovascular, hepatic, diabetic, renal, muscular dystrophy and autoimmune conditions; DSCs are becoming extremely relevant in tissue engineering and regenerative medicine.

Human ex vivo dentin-pulp complex preservation in a full crown model.

OBJECTIVES: Currently, there is lack of human in vitro full tooth models that hold the odontoblast layer with pulp tissue in their native environment. The appearance of new in vitro and in vivo models has provided new understanding of the potential of tissue engineering in dental pulp regeneration. However, the development of new in vitro full tooth models will allow us to get closer to in vivo conditions. Thus, the aim of this study is to preserve a living dentin-pulp complex, in a novel in vitro full crown model, after tooth extraction. METHODS: Twenty intact third molars, after preparation, were divided into four groups, with five samples each. We placed the negative control samples (C) in saline, and the tested groups were placed (T) in supplemented DMEM, at two different times: 1 and 7 days. The specimens were processed for light microscopy observation. RESULTS: Contrary to C-groups, T-groups showed a functional dentin-pulp complex. The treated dentin-pulp complex presents normal histological appearance. CONCLUSIONS: This study showed that it is possible to preserve a living dentin-pulp complex after tooth extraction during 7 days.

Industrial noise and tooth wear - experimental study.

UNLABELLED: Tooth wear is a complex multifactorial process that involves the loss of hard dental tissue. Parafunctional habits have been mentioned as a self-destructive process caused by stress, which results in hyperactivity of masticatory muscles. Stress manifests itself through teeth grinding, leading to progressive teeth wear. The effects of continuous exposure to industrial noise, a "stressor" agent, cannot be ignored and its effects on the teeth must be evaluated. AIMS: The aim of this study was to ascertain the effects of industrial noise on dental wear over time, by identifying and quantifying crown area loss. MATERIAL AND METHODS: 39 Wistar rats were used. Thirty rats were divided in 3 experimental groups of 10 animals each. Animals were exposed to industrial noise, rich in LFN components, for 1, 4 and 7 months, with an average weekly exposure of 40 hours (8h/day, 5 days/week with the weekends in silence). The remaining 9 animals were kept in silence. The areas of the three main cusps of the molars were measured under light microscopy. STATISTICAL ANALYSIS USED: A two-way ANOVA model was applied at significance level of 5%. RESULTS: The average area of the molar cusps was significantly different between exposed and non-exposed animals. The most remarkable differences occurred between month 1 and 4. The total crown loss from month 1 to month 7 was 17.3% in the control group, and 46.5% in the exposed group, and the differences between these variations were significant (p<0.001). CONCLUSIONS: Our data suggest that industrial noise is an important factor in the pathogenesis of tooth wear.

Effects of industrial noise on circumpulpar dentin--a field emission scanning electron microscopy and energy dispersive spectroscopy analysis.

Chronic exposure to Industrial Noise (IN), rich in Low Frequency Noise (LFN), causes systemic fibrotic transformation and sustained stress. Dental wear, significantly increased with exposure to LFN, affects the teeth particularly through the circumpulpar dentin. Our goal is to understand the consequences of IN exposure on the circumpulpar dentin of Wistar rats. 10 Wistar rats were exposed to IN for 4 months, according to an occupationally simulated time schedule and 10 animals were used as age-matched controls. The first and the second upper and lower molars of each animal were processed for observation by Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive Spectroscopy (EDS) analysis was performed. In exposed animals FESEM showed a 2.0 to 6.0 µm-dense mineral band between dentin and the pulp with no regular continuity with the tubules. This structure had a few tubules where the odontoblasts processes could be observed embedded within the band and collagen fibers were trapped inside. EDS analysis revealed that it was hydroxyapatite similar to dentin, with a higher carbon content. FESEM results show that the band may be tertiary reparative dentin formed by odontoblast-like cells, but the increased amount of carbon (EDS) could mean that it is sclerotic dentin. IN should be acknowledge as a strong stimulus, able to cause an injury to odontoblasts and to the formation of reparative tertiary dentin, in a process that may accelerate the aging of the teeth, either by direct impact of acoustic pressure pulsations or by increased stress and dental wear.