Influence of endodontic treatment on systemic oxidative stress

Anti-inflammatory cerium-containing nano-scaled mesoporous bioactive glass for promoting regenerative capability of dental pulp cells

AIMS

This study aimed to investigate the anti-inflammatory and odontoblastic effects of cerium-containing mesoporous bioactive glass nanoparticles (Ce-MBGNs) on dental pulp cells as novel pulp-capping agents.

METHODOLOGY

Ce-MBGNs were synthesized using a post-impregnation strategy based on the antioxidant properties of Ce ions and proposed the first use of Ce-MBGNs for pulp-capping application. The biocompatibility of Ce-MBGNs was analysed using the CCK-8 assay and apoptosis detection. Additionally, the reactive oxygen species (ROS) scavenging ability of Ce-MBGNs was measured using the 2,7-Dichlorofuorescin Diacetate (DCFH-DA) probe. The anti-inflammatory effect of Ce-MBGNs on THP-1 cells was further investigated using flow cytometry and quantitative real-time polymerase chain reaction (RT-qPCR). Moreover, the effect of Ce-MBGNs on the odontoblastic differentiation of the dental pulp cells (DPCs) was assessed by combined scratch assays, RT-qPCR, western blotting, immunocytochemistry, Alizarin Red S staining and tissue-nonspecific alkaline phosphatase staining. Analytically, the secretions of tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were detected with enzyme-linked immunosorbent assay (ELISA).

RESULTS

Ce-MBGNs were confirmed to effectively scavenge ROS in THP-1-derived macrophages and DPCs. Flow cytometry and RT-qPCR assays revealed that Ce-MBGNs significantly inhibited the M1 polarization of macrophages (Mφ). Furthermore, the protein levels of TNF-α and IL-1β were downregulated in THP-1-derived macrophages after stimulation with Ce-MBGNs. With a step-forward virtue of promoting the odontoblastic differentiation of DPCs, we further confirmed that Ce-MBGNs could regulate the formation of a conductive immune microenvironment with respect to tissue repair in DPCs, which was mediated by macrophages.

CONCLUSIONS

Ce-MBGNs protected cells from self-produced oxidative damage and exhibited excellent immunomodulatory and odontoblastic differentiation effects on DPCs. As a pulp-capping agent, this novel biomaterial can exert anti-inflammatory effects and promote restorative dentine regeneration in clinical treatment. We believe that this study will stimulate further correlative research on the development of advanced pulp-capping agents.

Is there any association between the presence of biomarkers and apical periodontitis? A systematic review

This systematic review aimed to verify whether there is evidence of an association between apical periodontitis and the presence of systemic biomarkers. This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses - PRISMA. For this, the acronym PECO was used; population (P) of adult humans exposed (E) to the presence of apical periodontitis, compared (C) to adult humans without apical periodontitis, and the outcome (O) of the presence of biomarkers was observed. The articles were searched in PubMed, Scopus, Web of Science, LILACS, Cochrane Library, OpenGray, and Google Scholar grey databases. Subsequently, studies were excluded based on title, abstract, and full article reading, following the eligibility criteria. The methodological quality of the selected studies was evaluated using the Newcastle-Ottawa qualifier. After exclusion, 656 studies were identified, resulting in 17 final articles that were divided into case-control, cross-sectional, and cohort studies. Eight studies were considered to have a low risk of bias, one had a medium risk of bias, and eight had a high risk of bias. In addition, 12 articles evaluated biomarkers in blood plasma, four evaluated them in saliva, and only one evaluated them in gingival crevicular fluid. The results of these studies indicated an association between apical periodontitis and the systemic presence of biomarkers. These markers are mainly related to inflammation, such as interleukins IL-1, IL-2, and IL-6, oxidative markers, such as nitric oxide and superoxide anions, and immunoglobulins IgG and IgM.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier (CRD42023493959).

Experimental apical periodontitis alters salivary biochemical composition and induces local redox state disturbances in the salivary glands of male rats

OBJECTIVES

The objective was to evaluate the effects of experimental apical periodontitis on the inflammatory, functional, biochemical, and redox parameters of the parotid and submandibular glands in rats.

MATERIALS AND METHODS

Twenty 12-week-old male Wistar rats were randomly divided into two groups (n = 10): a control group and apical periodontitis group. After 28 days, the saliva was collected for salivary flow rate and biochemistry composition. Both glands were sampled for quantification of the tumor necrosis factor-alpha (TNF-α) and biochemical analyses of redox state.

RESULTS

TNF-α concentrations were higher in both salivary glands adjacent to the periapical lesions in animals with apical periodontitis and also compared to the control group. The apical periodontitis group increased the salivary amylase, chloride, potassium, calcium, and phosphate. The total oxidant capacity increased in the parotid gland adjacent to the periapical lesions in the same rat and compared to the control group. Conversely, the total antioxidant capacity of the parotid glands on both sides in the apical periodontitis group was lower than that in the control group. Furthermore, glutathione peroxidase activity increased in the submandibular gland adjacent to the apical periodontitis group compared to the control group.

CONCLUSIONS

Experimental apical periodontitis alters salivary biochemical composition, in addition to increasing inflammatory marker and inducing local disturbances in the redox state in the parotid and submandibular glands of male rats.

CLINICAL RELEVANCE

Apical periodontitis could exacerbate the decline in oral health by triggering dysfunction in the salivary glands.

Primary apical periodontitis correlates to elevated levels of interleukin-8 in a Swedish population: A report from the PAROKRANK study

AIM

To explore associations between root filled teeth, primary and secondary apical periodontitis, and levels of inflammatory markers in blood from patients with a first myocardial infarction and matched controls.

METHODOLOGY

Between May 2010 and February 2014, 805 patients with a first myocardial infarction and 805 controls, matched for sex, age, and postal code area, were recruited to the multicentre case-control study PAROKRANK (periodontitis and its relation to coronary artery disease). All participants underwent a physical and oral examination, as well as blood sampling. Using panoramic radiography, root filled teeth, primary apical periodontitis, and secondary apical periodontitis were assessed by three independent observers. Blood samples were analysed with enzyme-linked immunosorbent assay method for the following inflammatory markers: interleukin-1β (IL-1β), IL-2, IL-6, IL-8, IL-12p70, tumour necrosis factor-α, and high-sensitivity C-reactive protein (hsCRP). Additionally, white blood cell count and plasma-fibrinogen were analysed. Associations between endodontic variables and the levels of inflammatory markers were statistically analysed with Mann-Whitney U-test and Spearman correlation, adjusted for confounding effects of baseline factors (sex, age, myocardial infarction, current smoking, diabetes, family history of cardiovascular disease, education, marital status, and periodontal disease).

RESULTS

Mean age of the cohort was 62 years, and 81% were males. Root fillings were present in 8.4% of the 39 978 examined teeth and were associated with higher levels of hsCRP, fibrinogen, and leukocyte count, but lower levels of IL-2 and IL-12p70. After adjusting for confounders, root filled teeth remained associated with higher levels of fibrinogen, but lower levels of IL-1β, IL-2, IL-6, and IL-12p70. Primary apical periodontitis was found in 1.2% of non-root filled teeth and associated with higher levels of IL-8 (correlation 0.06, p = .025). Secondary apical periodontitis was found in 29.6% of root filled teeth but did not relate to the levels of any of the inflammatory markers.

CONCLUSIONS

This study supports the notion that inflammation at the periapex is more than a local process and that systemic influences cannot be disregarded. Whether the observed alterations in plasma levels of inflammatory markers have any dismal effects on systemic health is presently unknown but, considering the present results, in demand of further investigation.

Modulation of blood redox status by the progression of induced apical periodontitis in rats

This study aimed to investigate if apical periodontitis in different periods changes systemic levels of the antioxidant and pro-oxidant parameters in Wistar rats. Twenty-four rats were randomly allocated into healthy animals, apical periodontitis at 14 days (AP14) and apical periodontitis at 28 days (AP28). The first mandibular molars were accessed in the AP groups, and the pulp chamber was exposed to the oral environment, inducing the apical lesion. After 14 and 28 days, the animals were anesthetized, euthanized, and hemimandibles were collected for micro-computed tomography (micro-CT) analysis to measure lesion volume, bone volume (BV), percent of bone to total tissue volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular space (Tb.Sp). A histological examination of the remaining bone was also performed. Finally, blood samples were collected for oxidative biochemistry analysis, investigating glutathione (GSH), Trolox equivalent antioxidant capacity (TEAC), and lipid peroxidation (TBARS). The lesion volume was greater at 28 than at 14 days, as shown by micro-CT. AP14 and AP28 had decreased BV and Tb.Th, but only AP28 showed a reduction in BV/TV. Tb.N and Tb. Sp were increased in apical periodontitis at 28 days. In the histopathological analysis, AP14 had focal regions of moderate mononuclear inflammatory infiltrate, and AP28 had an intense inflammatory infiltrate with bacterial colonies. In the biochemical evaluation, GSH, TEAC, and TBARS were increased after 14 days. However, GSH returned to control levels, TEAC was similar to AP14, and TBARS increased significantly after 28 days. Therefore, the oxidative biochemistry response was modulated according to the progression of periapical damage. After 14 days, the organism could still react to the injury. However, at 28 days, the antioxidant response decreased, associated with an increase in TBARS.

Effect of endodontic treatment on endothelial dysfunction and subclinical atherosclerosis-a prospective intervention study

OBJECTIVE

The objective of this study is to investigate the effect of endodontic treatment on flow-mediated dilatation (FMD) and carotid intima-media thickness (c-IMT) in patients with apical periodontitis (AP).

MATERIAL AND METHOD

The study includes 32 young men having AP with a mean age of 25.78 years free from cardiovascular disease (CVD) and its risk factors, including periodontitis. All subjects underwent complete physical and dental examination, echocardiography, and ultrasound assessment of FMD on the brachial artery and c-IMT on the carotid artery at baseline and 12 months after the endodontic treatment. Data were analyzed using paired Student's t-test and Pearson's correlation coefficient (r) test using SPSS 26 version.

RESULTS

Endodontic treatment leads to the improvement of FMD significantly from a pooled baseline value of 4.84 ± 1.55% to 7.68 ± 2.08% (p < 0.05). The study also depicts a statistically significant difference between c-IMT (mean = 0.62 ± 0.11 mm) before treatment as compared to 12 months after treatment (mean = 0.59 ± 0.11 mm) (p < 0.05).

CONCLUSION

Endodontic treatment leads to improved FMD and decreased c-IMT suggesting that treating AP can be help revert the early stages of CVD.

CLINICAL RELEVANCE

AP could be a potential etiological factor of future CVD and should be treated as soon as diagnosed.

Influence of Direct Pulp Capping with Calcium Hydroxide and Mineral Trioxide Aggregate on Systemic Oxidative Stress in Rats

Direct pulp capping is a procedure where materials are placed on exposed vital pulp tissue in order to stimulate reparative dentinogenesis and preserve pulp vitality. Carious pulp exposure and direct pulp capping are usually accompanied by pulp inflammation which can affect pro- and anti-oxidative systems locally or systemically. Therefore, this study aimed to investigate the potential influence of direct capping of inflamed rat dental pulp with calcium hydroxide (CH) and mineral trioxide aggregate (MTA) on parameters of systemic oxidative status.

Dental pulps of the first maxillary molars of Albino rats (n=32) were exposed and capped with either CH (n=8), MTA (n=8) or were left untreated (n=8). Animals with healthy pulp were used as a healthy control (n=8). After four weeks, animals were euthanized and blood samples were collected for biochemical analysis of parameters of systemic oxidative stress by spectrophotometric method.

Untreated control had the significantly higher (p <0.05) values of pro-oxidative parameters and lower (p <0.05) values of anti-oxidative parameters (superoxide dismutase and reduced glutathione) compared to healthy control. CH and MTA groups showed reduced values of pro-oxidative parameters compared to untreated control and values of anti-oxidative parameters comparable to healthy control.

Pulp exposure led to disbalance in systemic oxidative parameters while direct pulp capping with calcium hydroxide and mineral trioxide aggregate restored the levels of systemic oxidative parameters to that of animals with healthy dental pulp. These results indicate the importance of direct pulp capping and the potential influence of untreated inflamed pulp on systemic health.

Association between Endodontic Infection, Its Treatment and Systemic Health: A Narrative Review

The ‘Focal Infection Era in Dentistry’ in the late 19th and early 20th century resulted in widespread implementation of tooth extraction and limited the progress of endodontics. The theory proposed that bacteria and toxins entrapped in dentinal tubules could disseminate systemically to remote body parts, resulting in many types of degenerative systemic diseases. This theory was eventually refuted due to anecdotal evidence. However, lately there has been increased interest in investigating whether endodontic disease could have an impact on general health. There are reviews that have previously been carried out on this subject, but as new data have emerged since then, this review aims to appraise the available literature investigating the dynamic associations between apical periodontitis, endodontic treatment, and systemic health. The available evidence regarding focal infection theory, bacteraemia and inflammatory markers was appraised. The review also collated the available research arguing the associations of apical periodontitis with cardiovascular diseases, diabetes mellitus, adverse pregnancy outcome and autoimmune disorders, along with the effect of statins and immunomodulators on apical periodontitis prevalence and endodontic treatment prognosis. There is emerging evidence that bacteraemia and low-grade systemic inflammation associated with apical periodontitis may negatively impact systemic health, e.g., development of cardiovascular diseases, adverse pregnancy outcomes, and diabetic metabolic dyscontrol. However, there is limited information supporting the effect of diabetes mellitus or autoimmune disorders on the prevalence and prognosis post endodontic treatment. Furthermore, convincing evidence supports that successful root canal treatment has a beneficial impact on systemic health by reducing the inflammatory burden, thereby dismissing the misconceptions of focal infection theory. Although compelling evidence regarding the association between apical periodontitis and systemic health is present, further high-quality research is required to support and establish the benefits of endodontic treatment on systemic health.

Essential oils utility implications in symptomatic Burning Mouth Syndrome

Introduction. Burning mouth syndrome (BMS) is a clinical condition characterized by the presence of chronic pain in absence of clinically visible lesions of the oral mucosa. The etiology is uncertain and the therapeutic strategies still controversial. The objective of this prospective study is to analyze the efficacy of essential oils-based mouthwashes in the therapy of BMS. Material and method. This study included 16 patients affected by BMS who were treated with essential oils-based mouthwashes and glucose solution on alternated days for 30 days. Symptomatology was evaluated after 15, 30 and 90 days. Results and discussions. A the end of the treatment, most of the patients (67%) referred an improvement of symptoms up to complete remission in 90 days. Conclusions. Based on this study, essential oils-based mouthwashes could represent a valid aid in the treatment of BMS. Further studies are necessary in order to identify effective and standardized therapeutic protocols. Keywords: Burning Mouth Syndrome; oral rinse; essential oils; therapeutic strategies,

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.

Cardiac, biochemical and histopathological analysis reveals impaired heart function in hypertensive rats with apical periodontitis

AIM

To investigate the association between experimentally induced apical periodontitis (AP) and heart function in hypertensive rats.

METHODOLOGY

Forty-eight normotensive Wistar albino and spontaneously hypertensive (SHR) rats were divided into four equal groups: control (C), normotensive with AP (AP), SHR and SHR with AP (SHR + AP). AP was induced on the first right mandibular molars by exposing the pulp chambers to the oral environment for four weeks and confirmed radiographically. Thereafter, the animals were sacrificed by cervical dislocation, whilst hearts were isolated and perfused according to the Langendorff technique gradually increasing coronary perfusion pressures 40-120 cmH₂ O. The hemimandibles were analysed radiographically (mm² and pixels) to verify the presence of AP. Biomarkers of cardiac oxidative stress (OS) were determined in coronary venous effluent and cardiac tissue homogenate. Cardiac tissue was analysed histopathologically for signs of heart damage (oedema, fibrosis and necrosis). All data were analysed by Kruskal-Wallis and one-way anova tests (p < .05).

RESULTS

The levels of the maximum left ventricular pressure development rate of the SHR + AP group were significantly increased compared to the AP and C groups, and of the SHR group compared with the C group (p < .05). The levels of the minimum left ventricular pressure development rate of the SHR + AP group were significantly decreased compared to the AP, SHR and C groups, and of the SHR group compared to the C group (p < .05). The radiographic AP area was significantly larger in the SHR + AP group than in the AP group (p < .01). The levels of superoxide anion were significantly higher in the SHR + AP group than in the AP, SHR and C groups (p < .05). The activities of superoxide dismutase in cardiac tissue homogenate were significantly lower in the SHR + AP and AP groups compared with the SHR and C groups (p < .05).

CONCLUSIONS

In rats, AP was associated with impaired cardiodynamics, disturbed cardiac OS, antioxidant defence and cardiac pathologic changes in hypertensive conditions. Hypertension was associated with an increase in the AP radiographic area. Further studies should confirm whether root canal treatment can have a cardioprotective effect and reduce cardiac OS in hypertensive conditions.

Reactive oxygen species can be traced locally and systemically in apical periodontitis: A systematic review

OBJECTIVES

The aim of this systematic review was to summarize the existing evidence on the local production and systemic traces of reactive oxygen species (ROS) in apical periodontitis (AP).

DESIGN

A search of MEDLINE-PubMed and EMBASE was conducted up to January 12 of 2021 to identify studies in 6 different languages. Eligibility was evaluated and data were extracted from the eligible studies following the predefined objective. The Newcastle-Ottawa Scale was used for quality assessment of the included studies.

RESULTS

After screening, 21 papers met the inclusion criteria. Six studies were about systemic oxidative stress, 14 studies examined local production of reactive oxygen species and one studied both. ROS modulate cell signalling and cause oxidant imbalance locally at the site of AP. Cell signalling leads to a pro-inflammatory response, activation of MMPs and formation and progression of the AP lesion. Simultaneously, these oxidative stress biomarkers are also found in blood and saliva of subjects with AP.

CONCLUSIONS

Understanding the mechanism of ROS generation, involved in chronic inflammation, can provide us with important information to enhance local and systemic healing and possibly improve diagnostic tools. Future research considerations would be to use antioxidants to accelerate the return to oxidative balance.

Quantitative proteomic analysis in symptomatic and asymptomatic apical periodontitis

AIM

To quantitatively and qualitatively compare the host proteomic profile in samples of symptomatic and asymptomatic apical periodontitis (AP) using nano-liquid chromatography-electron spray tandem mass spectrometry.

METHODOLOGY

Samples were obtained from 18 patients with radiographically evident AP, divided into symptomatic and asymptomatic groups (nine per group) according to clinical characteristics. After sample collection, protein extraction, purification and quantification of the samples were performed, which were analysed by reverse-phase liquid chromatography coupled to mass spectrometry. Label-free quantitative proteomic analysis was performed by Protein Lynx Global Service software. Differences in expression of proteins between the groups were calculated using the Monte Carlo algorithm, considering P < 0.05 for down-regulated proteins and 1 - P > 0.95 for up-regulated proteins. Proteins were identified with the embedded ion accounting algorithm in the software and a search of the Homo sapiens UniProt database.

RESULTS

A total of 853 individual human proteins were identified. In the quantitative analysis, common proteins to both groups accounted for 143 proteins. Differences in expression between groups resulted in 51 up-regulated proteins (1 - P > 0.95) in the symptomatic group, including alpha-1-antitrypsin, protein S100-A8, myeloperoxidase, peroxiredoxin and lactotransferrin. This group also had 43 down-regulated proteins (P < 0.05), comprising immunoglobulin, neutrophil defensin, pyruvate kinase and alpha-enolase. The qualitative analysis considered only the exclusive proteins of each group. For the symptomatic group, 318 complete proteins and 29 fragments were identified, such as dedicator of cytokinesis protein, intersectin, prostaglandin, phospholipase DDHD2 and superoxide dismutase. For the asymptomatic group, 326 complete proteins and 37 fragments were identified, including azurocidin, C-reactive protein, collagen alpha, cathepsin, heat shock and laminin.

CONCLUSIONS

Quantitative differences in the expression of common proteins in cases of symptomatic and asymptomatic AP were found, which were mostly related to host immune response in both groups. Exclusive proteins in the symptomatic group were mainly related to the host response to the presence of viruses in endodontic infections, oxidative stress and proteolytic enzymes. The results provide a basis for a better understanding of cellular and molecular pathways involved in AP, establishing specific proteomic profiles for symptomatic and asymptomatic conditions.

Effect of Endodontic Treatment on Serum Glutathione (GSH) Levels in Patients with Chronic Apical Periodontitis: A Clinical Pilot Study

Aim:

To assess the before- and after-treatment levels of glutathione (GSH) in the serum of patients with chronic apical periodontitis.

Materials and Methods:

The study involved 20 systemically healthy patients with radiographic evidence of chronic apical periodontitis in at least one tooth, of which 11 were finally assessed. 10 mL of the patient’s venous blood was obtained before commencing the endodontic treatment to assess the pre-operative serum GSH levels (T0). The canals cleaned and shaped, and irrigated with 2.5% sodium hypochlorite, and filled with a calcium hydroxide based intracanal medicament. At the subsequent appointment after one week, teeth were obturated. The patients were recalled 30 days after the completion of endodontic therapy, and blood samples were assessed again at time frame T1 for serum GSH. The difference in pre- and post-treatment values for T0 and T1 was statistically analyzed.

Results:

The mean age of the subjects ( N = 11) was 21.09±3.24 years, with 19.50±0.71 years in female group and 21.44±3.50 years in the male group. The mean GSH at T0 was 11.73±8.30 units, which was increased to 14.04±13.96 units at T1. However, no significant change was observed in the GSH level from T0 to T1 (change = –2.30, t-value = –0.49, P = .635).

Conclusion:

The results of this study suggest that endodontic therapy may play a role in restoring the systemic oxidative balance, as seen by the increase in post-treatment serum GSH levels.

High-fat diet effect on periapical lesions and hepatic enzymatic antioxidant in rats

AIMS

To evaluate the effects of a high-fat diet (HFD) on the progression of apical periodontitis (AP), local inflammation, systemic antioxidant status, and blood lipid profile in rats.

MAIN METHODS

Sixteen male Wistar rats were fed a standard diet (SD) or a HFD. At the sixth experimental week, the pulp chambers of the mandibular first molars were exposed to develop AP. A glucose tolerance test was performed the week before euthanasia. At the tenth experimental week, the animals were euthanized and the livers were collected to estimate catalase (CAT) and reduced glutathione (GSH) levels. Blood was acquired for biochemical analysis. The size of AP was estimated from radiographs and described as AP size-to-body weight ratio; inflammatory grade of AP was determined by histological analysis.

KEY FINDINGS

At the end of the experimental period, the rats fed the HFD had 30% less weight (P < 0.0001) and higher blood glucose levels after 30 min of sucrose intake (P < 0.05) than those fed the SD. Animals from the HFD group had lower levels of CAT (P < 0.01), but the same was not observed in the GSH levels. Plasma insulin and total cholesterol were not affected by the diet. The rats fed the HFD presented greater AP than those fed the SD (P < 0.05). However, the local inflammatory infiltrate was similar in both groups.

SIGNIFICANCE

The alterations promoted by the consumption of a HFD were not only observed systemically, but also locally, producing greater AP in rats than a SD.

Cardiovascular diseases and apical periodontitis: association not always implies causality

Background

Several studies published in the last two decades have found an association between the prevalence of apical periodontitis (AP) or root canal treatment (RCT) and cardiovascular diseases (CVDs). However, the demonstration of association does not prove by itself the existence of a cause–effect relationship. Two diseases can appear as statistically related without any of them directly affecting the values of the other, resulting in a non-causal relationship. The aim of this narrative review is to summarize the current state of knowledge regarding the association between AP and CVDs, analysing it according to the Hill's causality criteria.

Material and Methods

Epidemiological studies carried out on the association between CVDs and AP or RCT published in English until 8 December 2019 were identified. Forty-four articles were selected and its results were analysed.

Results

Numerous cross-sectional epidemiological studies have found significant relationship between CVDs and AP. The odds ratio values range 1.6 - 5.4. However, other studies have not found significant association. Respect to RCT, some studies found correlation, but others found no association or even found that RCT is a protective factor against CVDs.

Conclusions

The results are inconsistent and a causal relationship between CVDS and endodontic disease cannot be stablished. The risk factors common to both diseases can act as confounding factors, biasing the results. To reach definitive conclusions about the type of association (causal or non-causal) between both diseases, longitudinal epidemiological studies must be carried out to establish the temporal relationship and the dose-response gradient.

Key words:Apical periodontitis, atherosclerosis, cardiovascular disease, coronary heart disease, endodontic medicine, root canal treatment.

Apical periodontitis induces changes on oxidative stress parameters and increases Na+/K+-ATPase activity in adult rats

OBJECTIVES

Endodontic infection can cause systemic alterations. The involvement of oxidative stress (OS) and transmembrane enzymes compose the pathogenesis of various systemic diseases. However, the relation among apical periodontitis (AP), OS parameters, and Na⁺/K⁺-ATPase (NKA) pump was not reported in the literature. This study evaluated the AP influence on OS parameters and NKA activity in adult rats.

METHODS

Adult male Wistar rats (sixteen weeks old) were randomly assigned to two experimental groups: control (CT group; n = 8) and AP (AP group; n = 9), which was induced in the first right mandibular molar tooth. After 21 days of AP induction, mandibles were dissected for radiographic analysis. In addition, the heart, liver, pancreas, and kidney were collected for analysis of endogenous OS parameters and NKA activity. Data were analyzed by Student's T-test. Values of p < 0.05 were considered statistically significant.

RESULTS

AP presence increased reactive species (RS) generation only in the heart, while the other analyzed organs did not have this parameter modified. Heart and pancreas had a decreased endogenous antioxidant system (catalase activity and vitamin C levels), liver and kidney had an increased one. AP increased NKA activity in the heart, liver, and pancreas, but not in the kidney.

CONCLUSION

The modulation of both endogenous antioxidant defense system and NKA activity in vital organs suggested that alterations in the antioxidant status and cellular electrochemical gradient may be involved in the AP pathophysiology.

Sex Hormones and Inflammation Role in Oral Cancer Progression: A Molecular and Biological Point of View

Oral cancers have been proven to arise from precursors lesions and to be related to risk behaviour such as alcohol consumption and smoke. However, the present paper focuses on the role of chronic inflammation, related to chronical oral infections and/or altered immune responses occurring during dysimmune and autoimmune diseases, in the oral cancerogenesis. Particularly, oral candidiasis and periodontal diseases introduce a vicious circle of nonhealing and perpetuation of the inflammatory processes, thus leading toward cancer occurrence via local and systemic inflammatory modulators and via genetic and epigenetic factors.

Apical Periodontitis Is Associated with Elevated Concentrations of Inflammatory Mediators in Peripheral Blood: A Systematic Review and Meta-analysis

INTRODUCTION

Apical periodontitis (AP), except for the local known consequences, may also be a systemic burden. Circulating inflammatory mediators that are released to sustain the AP lesion can in theory harm other bodily tissues. The aim of this systematic review was to summarize the existing evidence on the influence of AP on the peripheral blood levels of inflammatory mediators and markers of systemic stress.

METHODS

A search of MEDLINE-PubMed, Embase, and Cochrane was conducted up to and including February 2019 to identify studies in 5 different languages. The Newcastle-Ottawa Scale was used for quality assessment of the included studies.

RESULTS

Twelve of the 20 included studies were case-control studies, and 8 were intervention studies. The data of all the included studies were analyzed descriptively, whereas the data of 11 studies were available for meta-analyses. The study designs were heterogeneous. Nevertheless, the meta-analyses revealed statistically significant differences in C-reactive protein, interleukin 6, and asymmetric dimethylarginine levels between AP subjects and controls in peripheral blood. In addition, the concentration of C3 complement fragment in peripheral blood was significantly lower after the treatment and resolution of AP than before.

CONCLUSIONS

The existing literature indicates that AP adds on to systemic inflammation by elevating C-reactive protein, interleukin 6, asymmetric dimethylarginine, and C3 levels. In order to overcome the issue of large variation between study designs, future studies should have clear inclusion criteria, preferably larger cohorts, adequate follow-up of all subjects, and a thorough presentation of the data to enable further exploration of the possible burden of AP on general human health. Nevertheless, there is now stronger evidence that AP contributes to low-grade systemic inflammation.

Antisense yycG Regulation of Antibiotic Sensitivity of Methicillin-Resistant Staphylococcus aureus in Chronic Osteomyelitis

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is an urgent medical problem in osteomyelitis. The YycFG two-component regulatory system (TCS) allows bacteria to adapt rapidly to physical, chemical, and biological stresses. The recombinant plasmid shuttle vector was used to overexpress an antisense RNA (asRNA) to inhibit target gene expression by sequence-specific double-stranded RNA complex degradation. In the current study, antisense yycG RNA (ASyycG)-overexpression MRSA clinical isolates were constructed. Methods: Bacterial growth was monitored, and biofilm biomass was determined by crystal violet microtiter assay. Quantitative reverse transcription polymerase chain reaction analysis was used to identify expression of yycF/G/H and icaA/D in MRSA and ASyycG strains. The expression of YycG protein was quantified by Western blot assays. The antibiotic resistance of ASyycG strains was compared with that of the MRSA strains. Results: The ASyycG strains showed a decrease in growth rate compared with the MRSA strains. Of note, overexpression of ASyycG led to a reduction in biofilm formation and adhesion force. ASyycG strains had decreased expressions of the yycF/G/H and icaA/D. Furthermore, Western blot data showed that expression of the YycG protein decreased by 40% in ASyycG strains compared with MRSA strains. In addition, the effect of yycG asRNA improved the susceptibility of ASyycG strains to cefoxitin. Conclusions: The ASyycG strains inhibited biofilm organization and increased antibiotic sensitivity, which may be attributed to altered intracellular polysaccharide construction.

Association of Apical Periodontitis with Cardiovascular Disease via Noninvasive Assessment of Endothelial Function and Subclinical Atherosclerosis

INTRODUCTION

Chronic infections of endodontic origin might predispose to the onset of cardiovascular disease (CVD). The studies depicting the link between apical periodontitis (AP) and CVD are few, and the association is very controversial; also, the markers used are expensive, which makes them difficult to use in general practice. The purpose of this study was to investigate whether an association exists between AP and CVD using noninvasive methods (ie, flow-mediated dilatation [FMD] and carotid intima-media thickness [c-IMT]).

METHODS

This cross-sectional study included 120 men between 20 and 40 years old free from periodontal disease, CVD, and traditional cardiovascular risk factors; 60 subjects had AP, and 60 acted as controls. All subjects underwent complete physical and dental examination, echocardiography, ultrasound assessment of FMD of the right brachial artery, and c-IMT. Data were analyzed using the Mann-Whitney U test and the Spearman rank correlation (r_s) test.

RESULTS

FMD was found to be significantly impaired in patients with AP (mean = 4.9% ± 2.05%) compared with healthy controls (mean = 9.74% ± 2.59%, P = .000). The study also depicts statistically significant differences between c-IMT of the AP (mean = 0.64 ± 0.12 mm) and control (mean = 0.54 ± 0.08 mm) groups (P = .000). A significant inverse correlation between c-IMT and FMD was observed (r_s = -0.381, P = .000).

CONCLUSIONS

Impaired FMD and greater c-IMT in subjects with AP suggests a potential association between endodontic infection and CVD.

Effects of alpha-lipoic acid therapy on experimentally induced apical periodontitis: a biochemical, histopathological and micro-CT analysis

AIM

To investigate the possible therapeutic effects of alpha-lipoic acid (ALA) in a model of chronic apical periodontitis in rats by analysing biochemical, histopathological and micro-CT parameters.

METHODOLOGY

The study was approved by the Animal Ethics Committee of the Near East University. Thirty-two Wistar rats were divided into four groups of eight rats each: Control Group; ALA Group; AP Group; AP + ALA Group. In the AP and AP + ALA groups, the pulp chambers of the mandibular first molars were surgically exposed and were left open to the oral environment for 4-weeks to allow the establishment of periapical lesions. The rats in the Control and AP groups were treated intraperitoneally with saline solution (with a daily dose of 100 mg kg^-1 , for 28 days after periapical lesion induction). The rats in the ALA and AP + ALA groups were treated intraperitoneally with ALA (with a daily dose of 100 mg kg^-1 , for 28 days after periapical lesion induction). After decapitation, the trunk blood was collected for the assessment of biochemical parameters. The mandibles were surgically removed and dissected for histopathologic analysis and further scanned with micro-CT. Groups of data were compared with a two-way analysis of variance (two-way anova) followed by Sidak's multiple comparison tests. Values of P < 0.05 were regarded as significant.

RESULTS

TNF-α, IL-1β, MMP-1, MMP-2 levels were significantly lower in AP + ALA group compared with AP group (P < 0.05). There was a significant difference between the AP and AP + ALA groups according to assessment of the inflammatory scores (P < 0.05). The periapical inflammatory infiltrates were significantly more severe (P < 0.05) in the AP group. The AP + ALA group exhibited lower values both in terms of surface area and volume of resorption cavities than the AP group and this difference was significant (P < 0.05).

CONCLUSION

alpha-lipoic acid treatment provided therapeutic effects on the inhibition of periapical bone loss.

Inflammatory profile of chronic apical periodontitis: a literature review

Apical periodontitis caused by root canal infection is the most frequent pathological lesion in the jaws, mainly manifested as periapical granulomas and cysts. Understanding of the formation and progression of apical periodontitis as well as the identification of inflammatory biomarkers can help increase the knowledge of pathogenic mechanisms, improve the diagnosis and provide support for different therapeutic strategies. The objective of the present article is to review inflammatory biomarkers such as cytokines, chemokines, inflammatory cells, neuropeptides, RANK/RANKL/OPG system and other inflammatory markers and to relate these systems to the development and progression of pathological conditions related to apical periodontitis.

Decellularized Hydrogels in Bone Tissue Engineering: A Topical Review

Nowadays, autograft and allograft techniques represent the main solution to improve bone repair. Unfortunately, autograft technique is expensive, invasive and subject to infections and hematoma, frequently affecting both donor sites and surgical sites. A recent advance in tissue engineering is the fabrication of cell-laden hydrogels with custom-made geometry, depending on the clinical case. The use of ECM (Extra-Cellular Matrix)-derived Hydrogels from bone tissue is the new opportunity to obtain good results in bone regeneration. Several micro-engineering techniques and approaches are available to fabricate different cell gradients and zonal structures in hydrogels design, in combination with the advancement in biomaterials selection. In this review, we analyse the stereolithografy, the Bio-patterning, the 3D bioprinting and 3D assembly, the Laser-Induced Forward Transfer Bioprinting (LIFT), the Micro-extrusion bioprinting, the promising Electrospinning technology, the Microfluidics and the Micromolding. Several mechanical properties are taken into account for bone regeneration scaffolds. However, each typology of scaffold presents some advantages and some concerns. The research on biomaterials is the most promising for bone tissue engineering: the new biomimetic materials will allow us to obtain optimal results in the next clinical application of basic research.

Optimal Load for Bone Tissue Scaffolds with an Assigned Geometry

Thanks to the recent advances of three-dimensional printing technologies the design and the fabrication of a large variety of scaffold geometries was made possible. The surgeon has the availability of a wide number of scaffold micro-architectures thus needing adequate guidelines for the choice of the best one to be implanted in a patient-specific anatomic region. We propose a mechanobiology-based optimization algorithm capable of determining, for bone tissue scaffolds with an assigned geometry, the optimal value L_opt of the compression load to which they should be subjected, i.e. the load value for which the formation of the largest amounts of bone is favoured and hence the successful outcome of the scaffold implantation procedure is guaranteed. Scaffolds based on hexahedron unit cells were investigated including pores differently dimensioned and with different shapes such as elliptic or rectangular. The algorithm predicted decreasing values of the optimal load for scaffolds with pores with increasing dimensions. The optimal values predicted for the scaffolds with elliptic pores were found higher than those with rectangular ones. The proposed algorithm can be utilized to properly guide the surgeon in the choice of the best scaffold type/geometry that better satisfies the specific patient requirements.

Apical periodontitis in southern Estonian population: prevalence and associations with quality of root canal fillings and coronal restorations

Background

Apical periodontitis (AP) is an inflammatory disease around the apex of a tooth root. Reported prevalence of AP ranges from 27% to 83% while the data about most post-Soviet countries are still missing. Knowing the prevalence of AP within a certain population helps to plan the treatment need and evaluate the success of endodontic interventions. We aimed to collect data about prevalence and determining factors of AP for the first time in Estonia.

Methods

The cross-sectional study included 6552 patients (age 35.5±19.2 years). Radiographic examination was applied to investigate the prevalence of AP and quality of endodontic treatment.

Results

AP was diagnosed in 54.7% of subjects. Endodontically treated teeth were present in 58.2% of subjects. Periapical finding was present in 44.6% of endodontically treated and in 30.8% of untreated teeth.

Out of 181,495 teeth, 52.7% were intact. AP was diagnosed in 6.3% of teeth, 6.9% of teeth were endodontically treated.

Risk factors for AP included caries (OR = 2.30), male gender (OR = 1.44), too short (OR = 1.76) or too long root canal filling (OR = 2.51), root canal filling of low density (OR = 1.61) while not orthodontic appliance. Lower AP risk was associated with restoration of the tooth – filling (OR = 0.45), crown (OR = 0.34) and bridge (OR = 0.33).

Conclusions

AP is highly prevalent in Southern Estonian population. Most cases are associated with root canal-treated teeth. The overall quality of root canal fillings tends to be low, consistent with the mediocre outcome of treatment. Considerable efforts are required to improve the standards of endodontic treatment.

Electronic supplementary material

The online version of this article (10.1186/s12903-017-0429-7) contains supplementary material, which is available to authorized users.

Oxidative Stress in the Local and Systemic Events of Apical Periodontitis

Oxidative stress is involved in the pathogenesis of a variety of inflammatory disorders. Apical periodontitis (AP) usually results in the formation of an osteolytic apical lesion (AL) caused by the immune response to endodontic infection. Reactive oxygen species (ROS) produced by phagocytic cells in response to bacterial challenge represent an important host defense mechanism, but disturbed redox balance results in tissue injury. This mini review focuses on the role of oxidative stress in the local and associated systemic events in chronic apical periodontitis. During endodontic infection, ligation of Toll-like receptors (TLRs) on phagocytes' surface triggers activation, phagocytosis, synthesis of ROS, activation of humoral and cellular responses, and production of inflammatory mediators, such as, cytokines and matrix metalloproteinases (MMPs). The increment in ROS perturbs the normal redox balance and shifts cells into a state of oxidative stress. ROS induce molecular damage and disturbed redox signaling, that result in the loss of bone homeostasis, increased pro-inflammatory mediators, and MMP overexpression and activation, leading to apical tissue breakdown. On the other hand, oxidative stress has been strongly involved in the pathogenesis of atherosclerosis, where a chronic inflammatory process develops in the arterial wall. Chronic AP is associated with an increased risk of cardiovascular diseases (CVD) and especially atherogenesis. The potential mechanisms linking these diseases are also discussed.

Remineralization Strategies in Oral Hygiene: A Position Paper of Italian Society of Oral Hygiene Sciences-S.I.S.I.O. Working Group

Background/Objective:

The clinical conditions that lead to an alteration of the enamel structure are numerous. The diet high in sugars and acidifying substances, psychological stress that triggers parafunctional behaviors, the reduced intake of fiber-rich foods or alkalizing substances, together with other factors, contribute to demineralization of the tooth enamel. Dental mineralizing products on the current market are distinguished according to the dosage form, the active ingredient, the release technology, clinical indications and patient choice. Currently, it is necessary to propose to oral health professionals a guide to orient themselves in this chaotic choice, in order to prefer the most effective product for their own clinical target.

Methods:

Italian Society of Oral Hygiene Sciences-S.I.S.I.O. is one of the leading scientific Italian societies representing those dental hygienists working with high-quality standards and in agreement with scientific evidence: in the last year, the SISIO working group has carried out a study focused on remineralizing agents in dentistry, in order to give an authoritative point of view to indicate a guideline in the decision process of the choice of a remineralizing agent. We will report the results pointed out from the last consensus meeting in 2017.

Results:

We have reported the good the bad and the ugly have been discussed in a critical discussion of such topic.

Conclusion:

The SISIO experience has been reported in this position paper with the aim to serve as a useful aid in the daily choice of the clinical steps to perform, when dental professionals need to treat demineralized teeth.

Pregnancy and periodontal disease: does exist a two-way relationship?

Periodontal disease (PD) is an inflammatory disease of the tissues supporting the teeth. PD affects 65 million adults over the age of 30 years in the USA, and worldwide 5 to 70% of adults. Women who develop PD during pregnancy, it's estimated 1 woman in 5, may have a higher risk of adverse pregnancy outcomes. PD during pregnancy starts by dental plaque and is increased by the action of pregnancy hormones. In order to study the effect of PD on adverse pregnancy outcomes, we have performed this narrative review summarising the current studies about the influence of PD on pregnancy. Periodontal pockets are a reservoir of oral microbiota. Modifications in oral microbiota may be considered as a potential mechanism for developing PD during pregnancy. PD is surely caused by bacteria, but the progression and worsening are due to a host immune response. The inflammation caused by PD is not limited to the oral cavity. It is hypothesized that episodes of bacteraemia and dissemination of endotoxins from periodontal pockets can induce the activation of the systemic immune response. In conclusion our narrative review shows that there's no relationship between PD and adverse pregnancy outcomes, and PD treatment during pregnancy does not confer a general protection against adverse pregnancy outcomes.

Oxidative stress in patients with endodontic pathologies

BACKGROUND

Apical periodontitis (AP) is an inflammatory disease affecting periradicular tissues. It is a widespread condition but its etiopathogenetic mechanisms have not been completely elucidated and the current treatment options are not always successful.

PURPOSE

To compare oxidative stress (OxS) levels in the saliva and the endodontium (root canal [RC] contents) in patients with different endodontic pathologies and in endodontically healthy subjects.

PATIENTS AND METHODS

The study group of this comparison study included 22 subjects with primary chronic apical periodontitis (pCAP), 26 with posttreatment or secondary chronic apical periodontitis (sCAP), eight with acute periapical abscess, 13 with irreversible pulpitis, and 17 healthy controls. Resting saliva samples were collected before clinical treatment. Pulp samples (remnants of the pulp, tooth tissue, and/or previous root filling material) were collected under strict aseptic conditions using the Hedström file. The samples were frozen to -80°C until analysis. OxS markers (myeloperoxidase [MPO], oxidative stress index [OSI], 8-isoprostanes [8-EPI]) were detected in the saliva and the endodontium.

RESULTS

The highest MPO and 8-EPI levels were seen in pCAP and pulpitis, while the highest levels of OSI were seen in pCAP and abscess patients, as well as the saliva of sCAP patients. Controls showed the lowest OxS levels in both RC contents and saliva. Significant positive correlations between OxS markers, periapical index, and pain were revealed. Patients with pain had significantly higher OxS levels in both the endodontium (MPO median 27.9 vs 72.6 ng/mg protein, p=0.004; OSI 6.0 vs 10.4, p<0.001; 8-EPI 50.0 vs 75.0 pg/mL, p<0.001) and saliva (MPO 34.2 vs 117.5 ng/mg protein, p<0.001; 8-EPI 50.0 vs 112.8 pg/mL, p<0.001) compared to pain-free subjects.

CONCLUSION

OxS is an important pathomechanism in endodontic pathologies that is evident at both the local (RC contents) and systemic (saliva) level. OxS is significantly associated with dental pain and bone destruction.

The Protective Effect of Indole-3-Acetic Acid (IAA) on H2O2-Damaged Human Dental Pulp Stem Cells Is Mediated by the AKT Pathway and Involves Increased Expression of the Transcription Factor Nuclear Factor-Erythroid 2-Related Factor 2 (Nrf2) and Its Downstream Target Heme Oxygenase 1 (HO-1)

Indole-3-acetic acid (IAA) is the most common plant hormone of the auxin class and is known to have many effects including cell proliferation enhancement and antioxidant property. However, no study has revealed its defensive effects against oxidative toxicity in human dental pulp stem cells (hDPSCs). In this study, we investigated the effects of IAA on hydrogen peroxide- (H₂O₂-) induced oxidative toxicity in hDPSCs. H₂O₂-induced cytotoxicity was attenuated after IAA treatment. Cell cycle analysis using FACS showed that the damaged cell cycle and increased number of apoptotic cells by H₂O₂ treatment were recovered after the treatment of IAA. The H₂O₂-mediated increased expression of the proapoptotic genes, BAX and p53, was attenuated by IAA treatment, while IAA treatment increased antiapoptotic genes, BCL-2 and ATF5 expression. The increases of cleaved caspase-3 and ROS by H₂O₂ were also decreased after treatment of IAA. To further investigate the mechanism of IAA, Nrf2-related antioxidant pathway was examined and the results showed that the level of Nrf2 and HO-1 expressions, stimulated by H₂O_2, decreased after treatment of IAA. Moreover, IAA treatment protected hDPSCs against H₂O₂-induced oxidative stress via increased expression of Nrf2 and HO-1, mediated by the AKT pathway.

Ultrasound and analysis of the deformation patterns of the masseter muscle: comparing surgical anatomy, ultrasound and functional anatomy

PURPOSE

We have tried to demonstrate whether the analysis of the muscle strain allows us to identify the three distinct functional areas of the architecture of the masseter, as one would see them by performing or viewing an anatomical dissection of said muscle, and whether these sections have behave differently in terms of origin and coping of the strain they face (quantitative analysis).

MATERIALS AND METHODS

This work has been elaborated by the use of an ultrasound machine (MicrUs ext-1H Telemed Medical Systems Milano) and a linear probe (L12-5l40S-3 5-12 MHz 40 mm) which allowed us to record a 45 frame per second video (DCM). Videos has been elaborated by use of an ultrasound machine (MicrUs ext-1H Telemed Medical Systems Milano) and a linear probe (L12-5l40S-3 5-12 MHz 40 mm) which allowed us to record a 45 frame per second video (DCM). We applied to the resulting video a software (Mudy 1.7.7.2 AMID Sulmona Italy) for the analysis of muscle deformation patters (contraction, dilatation, cross-plane, vertical strain, horizontal strain, vertical shear, horizontal shear, horizontal displacement, vertical displacement). The number of videos of masseter muscles in contraction at maximum exertion due to dental clenching made during this research is around 12,000. Out of these we chose 1,200 videos which examine 200 patients (100 females, 100 males).

RESULTS

The deformation pattern analysis of the skeletal muscle on ultrasound basis seems to be an adequate instrument to use during the investigation of the functional structure of the masseter muscle given its ability to highlight the distinct activity of each separate part of the muscle.

CONCLUSIONS

Moreover the strain does not apply to the muscle uniformly; instead it varies according to the observed area.

Implant Dentistry: Monitoring of Bacteria Along the Transmucosal Passage of the Healing Screw in Absence of Functional Load

PURPOSE

To assess the changes in bacterial profile along the transmucosal path of healing screws placed immediately after insertion of two-piece endosseus implants during the 4-month osseointegration phase, in absence of functional load.

MATERIALS AND METHODS

Two site-specific samples were collected at the peri-implant mucosa of the healing screws of 80 two-piece implants, for a total of 640 samples. Implants placement was performed following a single protocol with flapless technique, in order to limit bacterial contamination of the surgical site. Identical healing screws (5 mm diameter/4 mm height) were used for each of the 80 implants. During the 4 months of the study, the patients followed a standard oral care regimen with no special hygiene maneuvers at the collection sites.

RESULTS

The present research documents that during the 4-month period prior to application of function load the bacterial profile of all sites exhibited a clear prevalence of cocci at the interface between implant neck and osteoalveolar crest margin.

CONCLUSIONS

A potentially pathogenic bacterial flora developed only along the peri-implant transmucosal path.

Light diffusion through composite restorations added with spherical glass mega fillers

PURPOSE

Evaluate how the spherical glass mega fillers (SGMFs) can positively interfere with light diffusion when incorporated in a composite restoration.

MATERIALS AND METHODS

30 samples (Ss) were performed, applying 2 composite layers of 3 mm each: 6 were made with composite only; 6 with a layer of SGMFs of O1.5mm within the first layer of composite; 6 with 2 overlapping layers of SGMFs of O1.5mm; 6 with a layer of SGMFs of O2mm; 6 with 2 overlapping layers of SGMFs of O2mm. The curing time was set at 40s for the first layer, and 120s for the second layer, transilluminated through the first layer. Digital pictures were taken, in standardized settings, during the transillumination, and the light intensity was measured with a digital image analysis software.

RESULTS

From a lateral view the Ss with a single layer of SGMFs of O1.5mm and O2mm, the relative increments of light intensity, were of 24.37% and 33.33% respectively. Concerning the Ss made with 2 layers of SGMFs, the relative increments were of 67.99% and 66.4% respectively. In front view has emerged a relative increase rate of light intensity of 53.66% and 79.58%, in the Ss with a single layer of SGMFs of O1.5mm and of O2mm respectively. Furthermore, in the Ss with two layers of SGMFs of O1.5mm and O2mm the relative increments were of 267.53 and 319.63% respectively.

CONCLUSION

The SGMFs are reliable in facilitating light diffusion within the light-curing composite resins.

Retrospective Analysis of the Correlation Between the Facial Biotype and the Inclination of the Upper Canine Cusp Axis to the Occlusal Plane

Permanent maxillary canines are the second most frequently impacted teeth and the prevalence of this clinical condition is estimated to be 1-2% in the general population. The diagnosis of maxillary canine impaction should be based on both clinical and radiographic examinations. The aim of this study was to evaluate the presence of a correlation between the facial biotype and the inclination of the upper cusp axis. A correlation between the total radicular length of the lateral incisors was also evaluated, by comparing the side of impaction with the healthy side. Twenty three patients with a diagnosis of unilateral upper cusp impaction were recruited. For each patient, dental casts and radiographic material (panoramic radiographs and lateral cephalograms) were examined. Statistical analyses were done with Spearman's rank correlation coefficient or Spearman's rho (ρ). X-ray examinations demonstrated that canine impaction was associated to other dental anomalies (32% of the sample). The mean α angle measurements were 22.9° ± 4.1°, and mean values of the β angle were 34.7°± 4.0°. The mean distance "d" value was 14.6 mm ± 1.2 mm. The mean values of the angle between the upper cusp axis and the perpendicular-to-Fh plane were 20.8° ± 2.6°. Among the 23 subjects recruited, 5 showed values included in the range 25°-45° and 1 an inclination > 45°. The results obtained in the present study demonstrate a significant inverse correlation between the MM angle and the inclination of the upper cusp axis to the perpendicular-to-Fh plane.

Bone Inflammation, Bone Infection and Dental Implants Failure: Histological and Cytological Aspects Related to Cement Excess

Background: Dental implant failure can recognize several causes and many of them are quite preventable with the right knowledge of some clinical critical factors. Aim of this paper is to investigate about the histological aspects related to dental implants failure in such cases related to cement excess, how such histological picture can increase the risk of bacterial infections and how the different type of cement can interact with osteoblasts in-vitro. Methods: We randomly selected 5 patients with a diagnosis of dental implant failure requiring to be surgically removed: in all patients was observed an excess of dental cement around the failed implants. Histological investigations were performed of the perimplant bone. Cell culture of purchased human Osteoblasts was performed in order to evaluate cell proliferation and cell morphology at 3 time points among 3 cement types and a control surface. Results: Dental cement has been related to a pathognomonic histological picture with a foreign body reaction and many areas with black particles inside macrophage cells. Finally, cell culture on different dental cements resulted in a lower osteoblasts survival rate. Conclusions: It is appropriate that the dentist puts a small amount of dental cement in the prosthetic crown, so to avoid the clinical alterations related to the excess of cement.

Effectiveness of two different desensitizing varnishes in reducing tooth sensitivity: a randomized double-blind clinical trial

PURPOSE

The aim of this study is to evaluate and compare the effectiveness of two different desensitizing varnishes.

MATERIALS AND METHODS

Ninety healthy adults suffering from tooth sensitivity were divided into three groups. Two different varnishes were used for the study: Fluor Protector S, containing 7700 ppm fluoride (group I), and Cervitec F, containing 1400 ppm fluoride and 0.3% chlorhexidine (group II). A placebo containing water and ethanol was applied for the third group. Tooth sensitivity was collected according the Schiff' scale at baseline and after 30 and 90 days.

RESULTS

Group I and group II improved with statistically significant results. Group III did not show any improvements.

CONCLUSIONS

Desensitizing varnishes are a valid treatment for tooth hypersensitivity.

Correlation between dento-skeletal characteristics and craniomandibular disorders in growing children and adolescent orthodontic patients: retrospective case-control study

PURPOSE

The aim of this retrospective case-control study was to identify, in a group of growing children and adolescents affected by malocclusion, specific dento-skeletal characteristics which could be correlated to the onset, in the above-mentioned subjects, of craniomandibular disorders (CMD).

MATERIALS AND METHODS

Among the patients treated at the Paedodontics and Orthodontics department of Bari Dental School, we recruited a group of patients with malocclusion and symptoms of temporomandibular disorders, as an experimental group. We considered as controls those patients who, match-paired to their skeletal class depending on the ANB angle, did not show any CMD sign or symptom.

RESULTS

Of the 128 examined patients, 15 showed signs and/or symptoms of CMD (11.7%). When compared to 15 patients non-affected by CMD, we could not detect statistically significant differences in both skeletal and occlusal characteristics. It is still interesting to notice how in CMD patients, characteristics of skeletal hyperdivergence are often to be found.

CONCLUSIONS

The present study seems to confirm that in growing children and adolescents, the presence of signs and/or symptoms of CMD is not associable to a specific vertical skeletal growth pattern or to other specific occlusal characteristics.

Quantitive evaluation of dentin sialoprotein (DSP) using microbeads - a potential early marker of root resorption

PURPOSE

This study had the aim of comparing two different methods of analysing dentin sialoprotein (DSP) in the gingival crevicular fluid (GCF): the conventional eLISA approach and a new method involving the use of magnetic micro-beads coated with an antibody specific for DSP prior to eLISA analysis.

MATERIALS AND METHODS

GCF was taken from six patients following twelve weeks of orthodontic treatment using paper strips inserted into the mesial and distal sulci of the upper incisors, and analysed using both methods.

RESULTS

Statistical analysis of the results using the Mann-Whitney non-parametric test showed that the micro-bead approach conferred more reliability and less variability on the conventional eLISA approach. Furthermore, this method, for the first time, enables the quantification of the DSP in the sample in ng/μl.

CONCLUSIONS

The innovative micro-bead/eLISA approach proposed provides a reliable means of quantifying the DSP in the GCF.

Different effectiveness of two pastas supplemented with either lipophilic or hydrophilic/phenolic antioxidants in affecting serum as evaluated by the novel Antioxidant/Oxidant Balance approach

Effectiveness in improving serum antioxidant status of two functional pastas was evaluated by the novel Antioxidant/Oxidant Balance (AOB) parameter, calculated as Antioxidant Capacity (AC)/Peroxide Level ratio, assessed here for the first time. In particular, Bran Oleoresin (BO) and Bran Water (BW) pastas, enriched respectively with either lipophilic (tocochromanols, carotenoids) or hydrophilic/phenolic antioxidants extracted from durum wheat bran, were studied. Notably, BO pasta was able to improve significantly (+65%) serum AOB during four hours after intake similarly to Lisosan G, a wheat antioxidant-rich dietary supplement. Contrarily, BW pasta had oxidative effect on serum so as conventional pasta and glucose, thus suggesting greater effectiveness of lipophilic than hydrophilic/phenolic antioxidants under our experimental conditions. Interestingly, no clear differences between the two pastas were observed, when AC measurements of either serum after pasta intake or pasta extracts by in vitro assays were considered, thus strengthening effectiveness and reliability of AOB approach.

Polymerization shrinkage and spherical glass mega fillers: effects on cuspal deflection

PURPOSE

The Authors analyzed the effect of spherical glass mega fillers (SGMF) on reducing contraction stress in dental composite resins, by means of a cavity model simulating the cuspal deflection which occurs on filled tooth cavity walls in clinical condition.

MATERIALS AND METHODS

20 stylized MOD cavities (C-factor = 0.83) were performed in acrylic resin. The inner surface of each cavity was sand blasted and adhesively treated in order to ensure a valid bond with the composite resin. Three different diameter of SGMF were used (i.e. 1, 1,5, 2 mm). The samples were divided in 4 groups of 5 each: Group 1 samples filled with the composite only; Group 2 samples filled with composite added with SGMFs, Ø1mm (16 spheres for each sample); Group 3 samples filled with composite added with SGMFs, Ø1,5 mm (5 spheres for each sample); Group 4 samples filled with composite added with SGMFs, Ø2 mm (2 spheres for each sample). Digital pictures were taken, in standardized settings, before and immediately after the polymerization of the composite material, placed into the cavities. With a digital image analysis software the distances from the coronal reference points of the cavity walls were measured. Then the difference between the first and second measurement was calculated. The data were analyzed by means of the ANOVA test.

RESULTS

A significative reduction on cavity walls deflection, when the composite resin is used in addiction with the SGMFs was observed. The SGMFs of smallest diameter (1mm) showed the better outcome.

CONCLUSION

The SGMFs are reliable in reducing contraction stress in dental composite resins.