Clinical characteristics and caries risk assessment of tobacco heating systems smokers, cigarette smokers and non-smokers: a cross-sectional study.

OBJECTIVES: The study compared clinical characteristics and caries risk assessments between tobacco heating system (THS) smokers, cigarette smokers and non-smokers. MATERIALS AND METHODS: General data, data regarding fluoridation, smoking and dietary habits was obtained through a questionnaire. Caries experience was assessed by the DMFT index; the amount of biofilm by the Full mouth plaque score index; the amount of salivation by the quantum of stimulated salivation test; salivary pH with pH indicator strips and salivary number of S.mutans and Lactobacilli by cultivation on agar plates. The Cariogram method was used to assess caries risk. RESULTS: No differences between the groups was detected regarding education level, average daily number of meals, fluoridation programs, systemic diseases, and caries experience. The groups significantly differed in the amount of salivary S.mutans and Lactobacilli (p < 0.001), accumulated biofilm (p = 0.034), salivation quantum (p < 0.001), and saliva pH (p = 0.009). Exposure to tobacco smoke and heated tobacco aerosol increased the accumulation of biofilm and decreased salivary pH. Smoking increased S. mutans, while THS consumption decreased salivation and Lactobacilli the most. The Cariogram analysis found no differences in chances of avoiding new caries lesions between the groups, but a significant difference in developing caries lesions due to dietary habits was detected (p < 0.001) with non-smokers having higher risk than smokers, but not than THS consumers. CONCLUSIONS: THS and cigarette smoking were related to clinical characteristics that affect caries activity even though the caries risk assessment revealed no significant difference in the chances of avoiding new caries lesions between the groups. CLINICAL RELEVANCE: THS and cigarette smokers could have higher caries activity than non-smokers. The clinical study protocol has been registered on ClinicalTrials.gov under the ID number: NCT06314100.

Comparison of apical irrigant solution extrusion among conventional and laser-activated endodontic irrigation.

The aim of this study was to determine the amount of extruded endodontic irrigant among needle-syringe irrigation (NSI) and laser-activated irrigation (LAI) regimens. Twenty extracted maxillary central incisors were prepared utilizing GT professional rotary files (size 40, taper 0.06). Irrigation was performed with two 27 G irrigation needles (notched open ended (ON) and single side vented (SV)) each at two different irrigant volumetric flow rates (VFR)-0.05 ml/s (3 ml/min) and 0.10 ml/s (6 ml/min). LAI was performed with Er:YAG (erbium-doped yttrium aluminum garnet) using different fiber types (X-Pulse-14/400 cylindrical tip, Preciso- 14/300 flat cylindrical tip, PIPS- 14/400 quartz tapered tip). The Er:YAG laser with a wavelength of 2940 nm (Lightwalker AT, Fotona, Ljubljana, Slovenia) was used according to the following protocol: 10 mJ per pulse, 15 Hz, pulse duration 50 µs. Irrigation time was 60 s for all protocols. Precision syringe pump (PSP) maintained constant irrigant volumetric flow rate. Apically extruded irrigant was collected and net weighed for each protocol (N = 10). Data were analyzed by t tests and Kruskal-Wallis. All LAI regimens had statistically significant lower irrigant extrusion compared with NSI except for the SV 27 G needle used with 0.05 ml/s VFR when compared with the Preciso fiber tip (p = 0,230). The largest amount of extruded irrigant was with the ON 27 G needle at the 0.10 ml/s VFR, while the smallest was after LAI with PIPS fiber tip. The lower quantity of apically extruded irrigant during LAI (X-Pulse and PIPS) points out a safer endodontic irrigation method compared with conventional irrigations.

Conservative endodontic management of a fused tooth: A case report.

OBJECTIVE: To report a conservative treatment of a rare developmental anomaly. CASE REPORT: A 73-year-old patient with previously initiated therapy and acute apical abscess of a maxillary right central incisor fused with the supernumerary tooth sought treatment. The conservative approach included nonsurgical root canal treatment and composite restoration. CONCLUSION: This case illustrates the importance of an individual approach when treating anomalous teeth. Priorities in pain and infection management to properly and functionally restore teeth should be unaffected by age.

Irrigation of human prepared root canal--ex vivo based computational fluid dynamics analysis.

AIM: To analyze the influence of the needle type, insertion depth, and irrigant flow rate on irrigant flow pattern, flow velocity, and apical pressure by ex-vivo based endodontic irrigation computational fluid dynamics (CFD) analysis. METHODS: Human upper canine root canal was prepared using rotary files. Contrast fluid was introduced in the root canal and scanned by computed tomography (CT) providing a three-dimensional object that was exported to the computer-assisted design (CAD) software. Two probe points were established in the apical portion of the root canal model for flow velocity and pressure measurement. Three different CAD models of 27G irrigation needles (closed-end side-vented, notched open-end, and bevel open-end) were created and placed at 25, 50, 75, and 95% of the working length (WL). Flow rates of 0.05, 0.1, 0.2, 0.3, and 0.4 mL/s were simulated. A total of 60 irrigation simulations were performed by CFD fluid flow solver. RESULTS: Closed-end side-vented needle required insertion depth closer to WL, regarding efficient irrigant replacement, compared to open-end irrigation needle types, which besides increased velocity produced increased irrigant apical pressure. For all irrigation needle types and needle insertion depths, the increase of flow rate was followed by an increased irrigant apical pressure. CONCLUSIONS: The human root canal shape obtained by CT is applicable in the CFD analysis of endodontic irrigation. All the analyzed values -irrigant flow pattern, velocity, and pressure - were influenced by irrigation needle type, as well as needle insertion depth and irrigant flow rate.

Absence of Oral Opportunistic Infections in Patients with Inflammatory Bowel Disease Receiving Anti-TNF-α and Anti-Integrin-α4ß7 Therapy.

Biological therapy of inflammatory bowel disease (IBD) carries an increased risk for the development of opportunistic infections due to immunomodulation. The aim of this study was to determine the prevalence and types of oral infections in IBD patients treated with biological (anti-TNF-α and anti-integrin-α4ß7) and conventional medication protocols. The study included 20 IBD patients receiving anti-TNF-α therapy, 20 IBD patients receiving anti-integrin-α4ß7 therapy and 20 IBD patients without immunomodulatory therapy. Participants completed questionnaires on medical information, oral lesions and symptoms. For each patient, clinical examination and a salivary flow rate test were performed, followed by a swab of the oral mucosa. The swab samples were cultured to identify Candida spp. and oral bacteria. No bacterial opportunistic infections were detected. Candidiasis was detected in four participants, with no significant difference between groups (p = 0.765). Hyposalivation was most common in the anti-TNF-α group, with a significant difference between groups (p = 0.036). There were no significant differences between groups in self-reported oral mucosal lesions and symptoms (p > 0.05), or in the distribution of oral mucosal lesions (p > 0.05). This study suggests that IBD patients receiving biological therapy are at no greater risk of developing oral opportunistic infections than IBD patients not receiving immunomodulatory therapy.

Association between Vitamin D and Candida-Associated Denture Stomatitis.

Candida-associated denture stomatitis (CADS) is a fungal infection affecting 60-65% of denture wearers. Its etiology is complex and multifactorial and often associated with host immunodeficiency. Evidence exists that vitamin D has potential immunomodulatory and anti-inflammatory effects. The aim of this case-control study was to assess the association between vitamin D levels and CADS. The study included 32 complete denture wearers with CADS and 32 sex- and age-matched complete denture wearers without CADS. The patients were clinically examined, and the severity of denture stomatitis was assessed according to Newton's classification scale. The serum vitamin D level was determined via the use of an electrochemiluminescence assay. The vitamin D level in the CADS group and control group was 54.68 ± 17.07 and 56.82 ± 17.75 nmol/L, respectively. There was no significant difference between the groups (p = 0.622). Univariate logistic regression analysis showed that the presence of CADS was not associated with hypovitaminosis D (odds ratio (OR) = 1.44; 95% confidence interval (CI) = 0.37-5.54). It can be concluded that vitamin D is not associated with CADS and does not play a significant role in host susceptibility to CADS. This finding suggests that vitamin D screening is not indicated routinely in patients with Candida-associated denture stomatitis.

The transition from pulpitis to periapical periodontitis in dogs' teeth.

The purpose of the study was to histologically analyse transition from pulpitis to periapical periodontitis on dog's teeth. Pulps of mandibular premolars (37 roots) were exposed using a low-speed handpiece. Teeth were left open to the oral environment for 20, 35, 50 and 65 days. After the experimental period animals were sacrificed. Undemineralised teeth with surrounding bone, embedded in methylmetacrylate, were prepared for standard histological analysis. All teeth with pulpitis (five roots), regardless of the experimental period, had acute serose periapical periodontitis. All teeth (15 roots) with partial pulp necrosis had subacute periapical periodontitis. Teeth with complete pulp necrosis (19 roots) had chronic periapical periodontitis and in one case suppurative apical periodontitis. The condition of the pulp correlates with the histopathological findings of periapical tissue in the open types of pulp infection. Acute periapical periodontitis begins during pulpitis and can occur before 20 days of pulp exposure in the dog.

Histological analysis of GFP expression in murine bone.

The power for appreciating complex cellular interactions during embryonic development using green fluorescent protein (GFP) as a visual histological marker has not been applied to adult tissues due to loss of GFP signal during paraffin embedding and a high autofluorescent background, particularly in section of bone and bone marrow. Here we demonstrate that the GFP signal is well preserved in frozen sections of adult decalcified bone. Using a tape-transfer system that preserves histological relationships, GFP expression can be related to standard histological stains used in bone biology research. The choice of a dual-filter cube and a strong GFP signal makes it possible to readily distinguish at least four different GFP colors that are distinctly different from the autofluorescent background. An additional advantage of the frozen sections is better preservation of immunological epitopes that allow colocalization of an immunostained section with an endogenous GFP and a strong lacZ signal emanating from a beta-gal marker gene. We present an approach for recording multiple images from the same histological section that allows colocalization of a GFP signal with subsequent stains and procedures that destroy GFP. Examples that illustrate the flexibility for dual imaging of various fluorescent signals are described in this study. The same imaging approach can serve as a vehicle for archiving, retrieving, and sharing histological images among research groups.

Cell death and cell proliferation in mouse submandibular gland during early post-irradiation phase.

The effects of irradiation on different cell compartments in the submandibular gland were analyzed in adult C57BL/6 mice exposed to X-ray irradiation and followed up for 10 days. Apoptosis was quantified using the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-digoxigenin nick end labeling method (TUNEL). Cell proliferation was detected using immunohistochemistry for proliferating cell nuclear antigen (PCNA). Radiation-induced apoptosis occurred rapidly, reaching a maximum 3 days post-irradiation. The percentage of apoptotic cells increased with the irradiation dose. At day 1 post-irradiation, cell proliferation was significantly reduced in comparison to sham-irradiated controls. After post-irradiation arrest of the cell cycle, proliferation increased in all gland compartments, reaching a maximum at day 6 post-irradiation. The proliferation response corresponded to the dose of irradiation. We suggest that the reason for gland dysfunction could be the coexistence of high apoptotic and proliferative activity in the irradiated gland.

Analysis of the odontogenic and osteogenic potentials of dental pulp in vivo using a Col1a1-2.3-GFP transgene.

Recently, transgenic mice that carry a Green Fluorescent Protein (GFP) reporter gene fused to 2.3 kb fragment of rat Col1a1 regulatory sequences (pOBCol2.3GFPemd) were generated. In the present study, we have examined the patterns of expression of Col1a1-2.3-GFP during odontoblast differentiation in this transgenic line. We report that Col1a1-2.3-GFP is expressed in newly differentiated odontoblasts secreting predentin and fully differentiated odontoblasts. The pattern of expression of Col1a1-2.3-GFP in odontoblasts is correlated with that of dentin sialophosphoprotein (DSPP). Col1a1-2.3-GFP is also expressed in the osteoblasts and osteocytes of alveolar bone. The pattern of expression of Col1a1-2.3-GFP in osteocytes is correlated with the expression of Dmp1. These observations indicate the 2.3 kb rat Col1a1 promoter fragment has sufficient strength and specificity to monitor the stage-specific changes during both odontoblast and osteoblast differentiation. We also used coronal pulp tissues isolated from postnatal pOBCol2.3GFPemd transgenic animals to follow their differentiation after transplantation under the kidney capsule. Our observations provide direct evidence that the dental pulp contains competent progenitor cells capable of differentiating into new generations of odontoblast-like cells which express high levels of Col1a1-2.3-GFP and DSPP and secrete tubular containing reparative dentin. We also report that the dental pulp is capable of giving rise to atubular bone-like tissue containing osteocytes expressing high levels of Col1a1-2.3-GFP and Dmp1. Our studies indicate that pOBCol2.3GFPemd transgenic animals provide a powerful tool for direct examination of the underlying mechanisms and the signaling pathways involved in dentin regeneration and repair, stem cell properties and heterogeneity of the dental pulp.

Expression and activity of osteoblast-targeted Cre recombinase transgenes in murine skeletal tissues.

The Cre/loxP recombination system can be used to circumvent many of the limitations of generalized gene ablation in mice. Here we present the development and characterization of transgenic mice in which Cre recombinase has been targeted to cells of the osteoblast lineage with 2.3 kb (Col 2.3-Cre) and 3.6 kb (Col 3.6-Cre) fragments of the rat Col1a1 promoter. Cre mRNA was detected in calvaria and long bone of adult Col 2.3-Cre and Col 3.6-Cre mice, as well as in tendon and skin of Col 3.6-Cre mice. To obtain a historical marking of the temporal and spatial pattern of Cre-mediated gene rearrangement, Col-Cre mice were bred with ROSA26 (R26R) mice in which Cre-mediated excision of a floxed cassette results in LacZ expression. In Col 2.3-Cre;R26R and Col 3.6-Cre;R26R progeny, calvarial and long bone osteoblasts showed intense beta-gal staining at embryonic day 18 and postnatal day 5. The spatial pattern of beta-gal staining was more restricted in bone and in bone marrow stromal cultures established from Col 2.3-Cre;R26R mice. Similar differences in the spatial patterns of expression were seen in transgenic bone carrying Col1a1-GFP visual reporters. Our data suggest that Col 2.3-Cre and Col 3.6-Cre transgenic mice may be useful for conditional gene targeting in vivo or for obtaining osteoblast populations for in vitro culture in which a gene of interest has been inactivated.

CO-OCCURRENCE OF CHRONIC HEAD, FACE AND NECK PAIN, AND DEPRESSION IN WAR VETERANS WITH POST-TRAUMATIC STRESS DISORDER.

This study investigated the relationship between chronic head, face and neck pain, and the level of depression in Croatian war veterans with post-traumatic stress disorder (PTSD). The presence of self-reported pain, pain on digital palpation, and pain severity in masticatory and neck muscles, temporomandibular joints and sinuses, as well as the level of depression were assessed in a group of war veterans with PTSD (n=52). Control groups consisted of war veterans without PTSD (n=50) and healthy men that were not engaged in war actions and were free from PTSD (n=50). The number of self-reported pain and number of painful sites were correlated with the level of depression. More self-reported pain and painful sites were recorded in the group of war veterans with PTSD as compared with either war veterans without PTSD or healthy men. Furthermore, PTSD patients mostly suffered from severe depression. There was a statistically significant positive correlation between all investigated pain parameters and level of depression. As the most important finding, the present study demonstrated chronic head, face and neck pain to be related to depression in PTSD patients.

Vertical force and torque analysis during mechanical preparation of extracted teeth using hand ProTaper instruments.

The purpose was to measure and analyse the vertical force and torque developed in the wider and narrower root canals during hand ProTaper instrumentation. Twenty human incisors were divided in two groups. Upper incisors were experimental model for the wide, while the lower incisors for the narrow root canals. Measurements of the force and torque were done by a device constructed for this purpose. Differences between the groups were statistically analysed by Mann-Whitney U-test with the significance level set to P<0.05. Vertical force in the upper incisors ranged 0.25-2.58 N, while in the lower incisors 0.38-6.94 N. Measured torque in the upper incisors ranged 0.53-12.03 Nmm, while in the lower incisor ranged 0.94-10.0 Nmm. Vertical force and torque were higher in the root canals of smaller diameter. The increase in the contact surface results in increase of the vertical force and torque as well in both narrower and wider root canals.

Distinct functions for Bmp signaling in lip and palate fusion in mice.

Previous work suggested that cleft lip with or without cleft palate (CL/P) is genetically distinct from isolated cleft secondary palate (CP). Mutations in the Bmp target gene Msx1 in families with both forms of orofacial clefting has implicated Bmp signaling in both pathways. To dissect the function of Bmp signaling in orofacial clefting, we conditionally inactivated the type 1 Bmp receptor Bmpr1a in the facial primordia, using the Nestin cre transgenic line. Nestin cre; Bmpr1a mutants had completely penetrant, bilateral CL/P with arrested tooth formation. The cleft secondary palate of Nestin cre; Bmpr1a mutant embryos was associated with diminished cell proliferation in maxillary process mesenchyme and defective anterior posterior patterning. By contrast, we observed elevated apoptosis in the fusing region of the Nestin cre; Bmpr1a mutant medial nasal process. Moreover, conditional inactivation of the Bmp4 gene using the Nestin cre transgenic line resulted in isolated cleft lip. Our data uncover a Bmp4-Bmpr1a genetic pathway that functions in lip fusion, and reveal that Bmp signaling has distinct roles in lip and palate fusion.

New insight into progenitor/stem cells in dental pulp using Col1a1-GFP transgenes.

In recent years there has been increasing progress in identifying stem cells from adult tissues and their potential application in tissue engineering. These advances provide a promising future for tooth replacement/regeneration. Essential for this approach is the identification of donor stem cells for various components of the teeth. Our studies show that pOBCol3.6GFPtpz and pOBCol2.3GFPemd transgenic animals provide a unique model to gain insight into stem cells in the dental pulp. Our in vivo studies of the developing teeth of these transgenic lines show both Col1a1-GFP transgenes are expressed in functional and fully differentiated odontoblasts. The patterns of expression of Col1a1-GFP transgenes during odontoblast differentiation correlates with the expression of DSPP. In the developing craniofacial bones both Col1a1-GFP transgenes are also expressed in osteoblasts and osteocytes of alveolar and calvarial bones. In the alveolar bones, the expression of Col1a1-GFP in osteocytes correlates with the expression of DMP1. Col1a1-3.6-GFP is expressed in the entire layer of the periosteum and in suture mesenchyme containing osteoprogenitor cells. On the other hand, Col1a1-2.3- GFP expression was limited to the osteoblastic layer of the periosteum and was not detected in the fibroblastic layer of the periosteum or in the suture mesenchyme. These observations indicate that Col1a1-3.6-GFP and Col1a1-2.3-GFP transgenes identify different subpopulations of cells during intramembranous ossification. By using the coronal portion of dental pulps isolated from postnatal transgenic mice our observations also provide direct evidence that the dental pulp contains progenitor/stem cells capable of giving rise to a new generation of odontoblast-like cells, as well as osteoblast-like cells.