Development of Rat Caries-Induced Pulpitis Model for Vital Pulp Therapy.

Rodent animal models for vital pulp therapy are commonly used in dental research because their tooth anatomy and cellular processes are similar to the anatomy and processes in humans. However, most studies have been conducted using uninfected sound teeth, which makes it difficult to adequately assess the inflammatory shift after vital pulp therapy. In the present study, we aimed to establish a caries-induced pulpitis model based on the conventional rat caries model and then evaluate inflammatory changes during the wound-healing process after pulp capping in a model of reversible pulpitis induced by carious infection. To establish the caries-induced pulpitis model, the pulpal inflammatory status was investigated at different stages of caries progression by immunostaining targeted to specific inflammatory biomarkers. Immunohistochemical staining revealed that both Toll-like receptor 2 and proliferating cell nuclear antigen were expressed in moderate and severe caries-stimulated pulp, indicating that an immune reaction occurred at both stages of caries progression. M2 macrophages were predominant in moderate caries-stimulated pulp, whereas M1 macrophages were predominant in the severe caries-stimulated pulp. Pulp capping in teeth with moderate caries (i.e., teeth with reversible pulpitis) led to complete tertiary dentin formation within 28 d after treatment. Impaired wound healing was observed in teeth with severe caries (i.e., teeth with irreversible pulpitis). During the wound-healing process in reversible pulpitis after pulp capping, M2 macrophages were predominant at all time points; their proliferative capacity was upregulated in the early stage of wound healing compared with healthy pulp. In conclusion, we successfully established a caries-induced pulpitis model for studies of vital pulp therapy. M2 macrophages have an important role in the early stages of the wound-healing process in reversible pulpitis.

Anaesthetic Efficacy of 4% Articaine in Comparison with 2% Lidocaine as Intraligamentary Injections after an Ineffective Inferior Alveolar Nerve Block in Mandibular Molars with Irreversible Pulpitis: A Prospective Randomised Triple-Blind Clinical Trial.

The objective of the current study was to compare the anaesthetic efficacy of supplemental intraligamentary (IL) injection of 4% articaine with that of 2% lidocaine in the mandibular first and second molars with irreversible pulpitis after an ineffective inferior alveolar nerve block injection (IANB) using the same anaesthetic in a randomised triple-blind clinical trial. Seventy-six adult patients, who were diagnosed with irreversible pulpitis in the mandibular first or second molars, were divided into 2 groups and received IANB randomly. In patients with lip numbness, anaesthesia was evaluated with the cold and electrical pulp (EPT) tests, and if the reported number on EPT was below 100, supplemental IL injection was administered using the same anaesthetic. The teeth were retested after 5 minutes. The Heft-Parker visual analogue scale was used to evaluate pain after IANB and IL injections. Statistical analysis was performed using repeated measures ANOVA, chi-square, and independent-sample and paired-sample t-tests. The results showed that there was no significant difference in the success rates of supplemental IL and IANB injections between articaine and lidocaine. Furthermore, there was no significant difference in the success rates of supplemental IL injection with lidocaine between the mandibular first and second molars. However, there was a significant difference in the success rates of supplemental IL injection with articaine between the mandibular first and second molars. Moreover, supplemental IL injections indicated no significant difference in the anaesthetic efficacy between articaine and lidocaine; nevertheless, they were more effective in the mandibular second molars, especially with articaine.

Analgesic and Neuroprotective Effects of Electroacupuncture in a Dental Pulp Injury Model-A Basic Research.

Irreversible pulpitis is an extremely painful condition and its consequence in the central nervous system (CNS) remains unclear. A mouse model of dental pulp injury (DPI) resembles the irreversible pulpitis profile in humans. This study sought to determine whether pain induced by DPI activates microglia and astrocytes in the trigeminal subnucleus caudalis (Vc), as well as increases levels of proinflammatory cytokines, and whether electroacupuncture (EA) can be a potential analgesic and neuroprotective therapy following DPI. Pain behavior was measured via head-withdrawal threshold (HWT) and burrowing behavior at days 1, 3, 7, 14 and 21 after DPI. A marked decrease in HWT and burrowing activity was observed from day 1 to 14 after DPI and no changes were seen on day 21. Microglial and astrocytes activation; along with high cytokine (TNFα, IL-1ß, and IL-6) levels, were observed in the Vc at 21 days after DPI. These effects were attenuated by verum (local and distal) EA, as well as oral ibuprofen administration. The results suggest that DPI-induced pain and glial activations in the Vc and EA exert analgesic efficacy at both local and distal acupoints. Furthermore, verum (local and distal) EA might be associated with the modulations of microglial and astrocytes activation.

Expression of autophagy­associated proteins in rat dental irreversible pulpitis.

Autophagy serves an important role in numerous diseases, as well as in infection and inflammation. Irreversible pulpitis (IP) is one of the most common inflammatory endodontic diseases, and autophagy has been reported to regulate IP in vitro. However, the level of autophagy in the IP pathogenic process in vivo remains unknown. The aim of the current study was, thus, to investigate the levels of autophagy­associated proteins in rats with IP in vivo. A rat dental IP model was successfully constructed, and five different time points (0, 1, 3, 5 and 7 days) were investigated. The levels of the autophagy­related 5 (ATG5), ATG7, light chain 3 (LC3) and Beclin­1 proteins exhibited a time­dependent increase in rats with IP, whereas the levels of mammalian target of rapamycin and p62/sequestosome 1 were decreased. In addition, the levels of ATG proteins were specifically increased in odontoblasts and microvascular endothelial cells in pulpitis tissue. Based on these findings, autophagy may serve an important role in IP, and the present study data provide a new insight into the IP pathogenesis and treatment.

Pulp response of rats submitted to bleaching and the use of different anti-inflammatory drugs.

This study aimed to evaluate neuropeptide expression after bleaching treatment using histopathological and immunohistochemical analyses and the effects of hydrocortisone and acetaminophen on pulp inflammation, sine dental bleaching and inflammation first occur, and only then, the treatmentt. Sixty-three rats were divided into three groups (n = 21) according to the pain-relieving therapy used: I-control; II-topical application of Otosporin for 10 min after the bleaching treatment; III-oral administration of paracetamol 30 min before whitening and then every 12h. In all the study groups, placebo gel was applied to the left upper jaw (control) and a 35% H2O2-based whitening gel was applied to the right upper jaw for 45 min. Seven animals from each group were euthanized at different time points: 0h after treatment, 24h, and 48h. After euthanasia, the first molar on each side was analyzed by histology and immunohistochemistry to assess the degree of inflammation and verify the presence of the neuropeptides, substance P (SP) and calcitonin gene-related peptide (CGRP). The data were analyzed using the statistical nonparametric Kruskal-Wallis test followed by Dunn's test for individual comparisons. Extensive areas of necrosis were observed in the groups that received bleaching treatment only, whereas reduced damage were obtained in the group treated with Otosporin. The immunohistochemical analysis showed positive immunolabeling in all groups, including the control, but this was stronger in the groups that received bleaching treatment. The best results were obtained in the group that received treatment with Otosporin. The use of Otosporin after dental bleaching minimized the side effects of this treatment.

Oral health status associated with sociodemographic factors of Nepalese schoolchildren: a population-based study.

OBJECTIVES: The aim of this study was to investigate the oral health of Nepalese schoolchildren relative to their sociodemographic characteristics. METHODS: This school-based, cross-sectional study was conducted among 5-6-, 12- and 15-year-old Nepalese children in 18 randomly selected districts of the 75 in Nepal. Clinical parameters were recorded according to the World Health Organization (WHO) guidelines. Results were presented as mean (SD) and proportions; the chi-square test, t-test and one way-ANOVA were also performed. The risk of dental caries in association with the place of residence was presented according to the outcome of a binary logistic regression analysis. RESULTS: The mean d-value for the 5-6-year-old children was 5.0 (4.22), which was higher than the mean D-values for the 12- and 15-year-old subjects, of 1.3 (1.77) and 1.9 (2.28), respectively. The youngest children, as well as children from the Kathmandu Valley, were likely to have more untreated caries lesions than children in the other age groups. The mean number of teeth with severe consequences of dental caries (pulpitis/ulceration/fistula/abscess or pufa/PUFA) was 1.3 (1.91) for the 5-6-year-old children, 0.1 (0.35) for the 12-year-old children and 0.3 (0.75) for the 15-year-old children. All age groups had gingival bleeding on probing in more than 15% of teeth. Children from rural locations had significantly more gingival bleeding than urban children. The same was true for 15-year-old girls compared with boys of the same age. CONCLUSIONS: Among Nepalese children, oral diseases are common, and geographical variation is prevalent. The health policy should address the alarming oral health situation and need for urgent treatment and population-based preventive programmes that is evident in Nepal.

INFLUENCE OF TRICALCIUM SILICATE ON COURSE OF TRAUMATIC PULPITIS.

The use of Tricalcium Silicate (TS) as an odontotropic preparation makes it possible to create a hermetic crown restoration with a high degree of adhesion. However, the use of TS silicate by direct pulp capping remains disputable. The aim of this study was to determine the effects of TS on course of traumatic pulpitis by detection of morpho-functional peculiarities of changes in pulp tissue. We performed experimental investigation (on rabbits, males, aging three-month) for study of the morpho-functional changes of the pulp tissues with modeling of traumatic pulpitis and direct pulp capping with TS preparation (8 animals, investigated group) and calcium hydroxide (Calasept, NORDISKA DENTAL) preparation (8 animals, comparison group). After 2nd and 6th weeks tissues of tooth were fixed in 10% formalin with performing routine proceeding after decalcification and making histological slides which were investigated. Manifestations of protective adaptive mechanisms have been revealed in the form of inflammatory process two weeks after the injury in the pulp tissue with its resolution six weeks after performing of direct pulp capping with TS with replacement of necrotic area by connective tissue with their delimitation from viable pulp tissue against a background of intensive formation of capillaries. Morphometric study proved dynamical changes of vascular number cross-sections per 1 mm2 from 69.31±4.76 (2 weeks) to 47.38±4.12 (6 weeks) with 49.2±3.47 vascular density in intact group. Cellular density of odontoblasts as changed from 3.92±1.03 x103 per 1 mm2 (2 weeks) to 7.49±1.51 x103 per 1 mm2 (6 weeks) with 8.3±1.02 x103 per 1 mm2 cellular density in intact group. Thus it can be argued that the use of TS as a material for direct pulp capping promotes more active regeneration processes.

Outcomes of Direct Pulp Capping by Using Either ProRoot Mineral Trioxide Aggregate or Biodentine in Permanent Teeth with Carious Pulp Exposure in 6- to 18-Year-Old Patients: A Randomized Controlled Trial.

INTRODUCTION: This study aimed to compare the success rates of direct pulp capping (DPC) by using either ProRoot Mineral Trioxide Aggregate (MTA) or Biodentine in the cariously exposed permanent teeth of 6- to 18-year-old patients. Gray discoloration was also evaluated. METHODS: Fifty-nine cariously exposed permanent teeth, including teeth with diagnosis of normal pulp, reversible pulpitis, or irreversible pulpitis, early periapical involvement, and exposure size of up to 2.5 mm, were included. Each patient with only 1 cariously exposed tooth was randomly allocated to DPC with either ProRoot MTA (n = 30) or Biodentine (n = 29). Patients were recalled every 6 months. Clinical and radiographic examinations were used to determine success. RESULTS: Fifty-five patients (mean age, 10 ± 2 years), 27 treated with ProRoot MTA and 28 with Biodentine, were included in the analysis. At mean follow-up of 18.9 ± 12.9 months, the success rate was 92.6% with ProRoot MTA and 96.4% with Biodentine (P > .05; difference, 4%; 95% confidence interval [CI], -8% to 16%). Biodentine was non-inferior to ProRoot MTA. Failures were distributed equally in all categories of pulpal diagnosis and occurred in teeth with no periapical involvement and small exposures (0.5 mm). The survival probabilities of DPC with ProRoot MTA and Biodentine were 0.92 (95% CI, 0.73-0.98) and 0.96 (95% CI, 0.80-0.99). No significant difference was observed between them (P > .05). Gray discoloration was observed only with ProRoot MTA (55%). CONCLUSIONS: Biodentine was non-inferior to ProRoot MTA when used as a DPC material for cariously exposed permanent teeth of 6- to 18-year-old patients. However, Biodentine did not cause any gray discoloration in this study.

Alternative Caries Management Options for Primary Molars: 2.5-Year Outcomes of a Randomised Clinical Trial.

Less invasive caries management techniques for treating cavitated carious primary teeth, which involve the concept of caries control by managing the activity of the biofilm, are becoming common. This study aimed to compare the clinical efficacy (minor/major failures) and survival rates (successful cases without any failures) of 3 carious lesion treatment approaches, the Hall Technique (HT), non-restorative caries treatment (NRCT), and conventional restorations (CR), for the management of occlusoproximal caries lesions (ICDAS 3-5) in primary molars. Results at 2.5 years are presented. A total of 169 children (3- to 8-year-olds) were enrolled in this secondary care-based, 3-arm parallel-group, randomised controlled trial. Participants were allocated to: HT (n = 52; sealing caries with stainless-steel crowns without caries removal), NRCT (n = 52; opening up the cavity and applying fluoride varnish), CR (n = 65; control arm, complete caries removal and compomer restoration). Statistical analyses were: non-parametric Kruskal-Wallis analysis of variance, Mann-Whitney U test and Kaplan-Meier survival analyses. One hundred and forty-two participants (84%; HT = 40/52; NRCT = 44/52; CR = 58/65) had follow-up data of 1-33 months (mean = 26). Overall, 25 (HT = 2, NRCT = 9, CR = 14) of 142 participants (17.6%) presented with at least 1 minor failure (reversible pulpitis, caries progression, or secondary caries; p = 0.013, CI = 0.012-0.018; Mann-Whitney U test). Ten (HT = 1, NRCT = 4, CR = 5) of 142 participants (7.04%) experienced at least 1 major failure (irreversible pulpitis, abscess, unrestorable tooth; p = 0.043, CI = 0.034-0.045). Independent comparisons between 2 samples found that NRCT-CR had no statistically significant difference in failures (p > 0.05), but for CR-HT (p = 0.037, CI = 0.030-0.040) and for NRCT-HT (p = 0.011, CI = 0.010-0.016; Kruskal-Wallis test) significant differences were observed. Cumulative survival rates were HT = 92.5%, NRCT = 70.5%, and CR = 67.2% (p = 0.012). NRCT and CR outcomes were comparable. HT performed better than NRCT and CR for all outcomes. This study was funded by the Paediatric Dentistry Department, Greifswald University, Germany (Trial registration No. NCT01797458).

Effect of different dental burs for experimental induction of pulpitis in mice.

OBJECTIVE: To evaluate the effect of using different dental burs on the development of pulpal inflammation after pulpal exposure in mice. DESIGN: Eighty-eight C57BL/6 mice were randomly assigned to group A (n=40), group B (n=40) and control group (n=8). The pulps of the maxillary first molars were occlusally exposed using » round burs and polishing burs in group A and B respectively. Animals were sacrificed randomly at 0h, 4h, 8h, 12h and 24h after pulpal exposure. Micro-CT scanning was used to determine the success rate of sample preparation. Pulpal tissue changes were evaluated by histopathologic and immunohistochemical analyses. RESULTS: The success rates of sample preparations were 85% in group A and 90% in group B. The mean maximum diameter of pulpal exposure area was 625.6±30.6µm in group A and 402.7±18.0µm in group B (p<0.05). In addition, the mean of the minimum remaining dentine thickness at the marked region of interest was 133.2±29.9µm in group A and 261.4±16.3µm in group B (p<0.05). Histopathologic staining demonstrated more signs of inflammation in both groups, as the duration of pulpal exposure increases. However, the rate of inflammatory progress was higher in group A, even spreading to the root pulp tissue within a few hours. For group B, the progress was relatively slow. CONCLUSIONS: Pulpal exposure with different sizes of dental burs affects changes in the development of pulpal inflammation in mice.

Caracterización de las pulpitis agudas / Characterization of acute pulpitis

Se realizó un estudio descriptivo transversal, desde mayo de 2014 hasta mayo de 2015, en la clínica estomatológica del policlínico Juan Bruno Zayas del municipio de Cifuentes, provincia de Villa Clara, con el objetivo de caracterizar las afecciones pulpares agudas en pacientes con edades de doce o mas años, con dentición permanente, de ambos sexos, y que estaban padeciendo de pulpitis agudas. La muestra quedó integrada por 312 personas. Se estudió la frecuencia de la enfermedad, así como las principales causas que la originaron. Las pulpitis agudas más comunes en Cifuentes fueron las reversibles, específicamente la pulpitis transitoria, causada por la caries dental y padecidas por hombres de 35-59 años(AU)

Pain from Dental Implant Placement, Inflammatory Pulpitis Pain, and Neuropathic Pain Present Different Somatosensory Profiles.

AIMS: To address the two following questions: (1) What kind of somatosensory abnormalities may be characterized in patients receiving dental implants (IMP), in ongoing inflammatory dental pulpitis (IP) patients, and in neuropathic pain (atypical odontalgia [AO]) patients? and (2) What sort of sensory and neural changes may result from dental implant placement surgery and pulpectomy? METHODS: A total of 60 subjects were divided into three groups: the IMP (n = 20), IP (n = 20), and AO groups (n = 20). Quantitative sensory testing (QST) was performed preoperatively (baseline) for all three groups and postoperatively at 1 month and 3 months after dental implant placement or pulpectomy (in the IMP group and IP group, respectively). Statistical analyses were completed with one-way and two-way analysis of variance and z score transformations (α = 5%). RESULTS: The main findings of this study indicated that: (1) Elevations in mechanical detection threshold (MDT) and in current perception threshold (CPT) related to C-fiber activation, indicating a loss of function, were found at baseline in IP patients; (2) Somatosensory abnormalities such as allodynia, reduced MDT and mechanical pain threshold (MPT), and impaired pain modulation were found in AO patients; (3) No somatosensory alterations after implant placement were found in the IMP group; and (4) Somatosensory alterations in the form of reduction in the CPT related to C-fiber activation were reported 3 months after pulpectomy in the IP group. CONCLUSION: This study showed that somatosensory abnormalities were evident in AO and IP patients, and somatosensory alterations were seen in IP patients even 3 months after pulpectomy. However, no somatosensory alterations were seen after implant placement.

Pulpal Tissue Inflammatory Reactions after Experimental Pulpal Exposure in Mice.

INTRODUCTION: The purpose of this study was to establish a stable experimental mice pulpal inflammatory model and to evaluate inflammatory reactions of pulpal tissue after pulpal exposure. METHODS: Pulpal inflammation was induced in 80 C57BL/6 mice by occlusal exposure of the pulp of the maxillary first molar. The mice were sacrificed randomly at 0, 1, 6, 12, 24, 48, and 72 hours after pulpal exposure. Mice without pulpal exposure served as controls. Maxillary teeth were obtained and prepared for histologic analyses and real-time polymerase chain reaction analyses. RESULTS: As the duration of pulpal exposure increases, the inflammatory reaction is exacerbated. Within 6 to 12 hours after pulpal exposure, pulp tissues experienced red blood cell extravasation to the destruction of the odontoblast layer. After 24 hours, necrosis was observed in the pulpal tissue; until 72 hours, necrosis spread to the whole coronal pulpal tissue, and a large number of inflammatory cells were found in the radicular pulpal tissue. The results of histomorphologic scores have the same trend; samples from the 72-hour group possessed the highest score followed by samples from other groups (P < .01). The expression levels of inflammatory cytokines increased over the 72 hours, and there was a high rate of inflammatory cytokine expression at 6 and 12 hours after pulpal exposure. CONCLUSIONS: Our study represents a stable mice model for studying pulpal inflammation in vivo. Mouse pupal inflammation progresses rapidly, with dramatic changes evident in just a few hours.

Epigenetic regulation in dental pulp inflammation.

Dental caries, trauma, and other possible factors could lead to injury of the dental pulp. Dental infection could result in immune and inflammatory responses mediated by molecular and cellular events and tissue breakdown. The inflammatory response of dental pulp could be regulated by genetic and epigenetic events. Epigenetic modifications play a fundamental role in gene expression. The epigenetic events might play critical roles in the inflammatory process of dental pulp injury. Major epigenetic events include methylation and acetylation of histones and regulatory factors, DNA methylation, and small non-coding RNAs. Infections and other environmental factors have profound effects on epigenetic modifications and trigger diseases. Despite growing evidences of literatures addressing the role of epigenetics in the field of medicine and biology, very little is known about the epigenetic pathways involved in dental pulp inflammation. This review summarized the current knowledge about epigenetic mechanisms during dental pulp inflammation. Progress in studies of epigenetic alterations during inflammatory response would provide opportunities for the development of efficient medications of epigenetic therapy for pulpitis.

Concrescencia clínica pero no histológica: presentación de un caso clínico / Fused roots does not imply concrescence: a case report with histological analysis

La concrescencia es una anomalía dentaria poco frecuente que se define como la unión de las raíces de dos dientes adyacentes a través del cemento. Aunque en la práctica clínica el término "concrescencia" es utilizado para referirse a todos los casos de unión entre las raíces de dos dientes adyacentes, para confirmar el diagnóstico de concrescencia es necesario un estudio histológico que demuestre la unión a nivel del cemento. Esta anomalía se ha identificado en el 0,8% de los casos de exodoncia de dientes permanentes, siendo su incidencia mayor en la región posterior del maxilar superior. La detección previa de la concrescencia mediante la exploración clínica y radiográfica es, la mayoría de las ocasiones, casi imposible, por lo que el diagnostico suele hacerse después de la extracción. No obstante, es conveniente que el clínico evalúe cada paciente y cada diente de forma exhaustiva para poder planificar, caso de que exista concrescencia, la técnica quirúrgica adecuada para la extracción. Por lo tanto, deben conocerse la incidencia e implicaciones de esta anomalía para llevar a cabo un diagnóstico y plan de tratamiento correcto. En este artículo se presenta un caso clínico de aparente concrescencia diagnosticado post-extracción y cuyo estudio histológico no mostró unión de cemento entre ambas raíces. Por lo tanto, en la práctica clínica es más conveniente utilizar el término "raíces fusionadas" que "concrescencia", el cual sólo debería ser utilizado después del examen histológico de la pieza extraída

Concrescence is a rare dental anomaly defined as the cemental union of two adjacent teeth. Concrescence diagnosis requires histological confirmation, but in the clinical practice the term "concrescence" is used to refer to all the cases of union of the roots of two adjacent teeth. The anomaly has been reported in extraction cases with an incidence of 0.8% in the permanent dentition. Also has been reported a higher incidence of concrescence in the posterior maxilla. It is prudent for the clinician to evaluate carefully each patient and each tooth to be removed for the possibility and desirability of a surgical extraction technique. Therefore, consideration should be given to the possible occurrence, recognition, and implications of this anomaly in diagnosis and treatment planning. Clinically and radiographically is nearly impossible to detect concrescent teeth, and most of these cases are diagnosed post extraction. The purpose of this article is to report a case of clinical concrescence between a retained third molar and an erupted second molar identified during the extraction, which histological study did not show cementum union between both roots. Thus, in the clinical practice is better to use the term "fused roots" than "concrescence", which would be used only after the histological examination of the specimen

Conditional TNF-α Overexpression in the Tooth and Alveolar Bone Results in Painful Pulpitis and Osteitis.

Tumor necrosis factor-α (TNF-α) is a proalgesic cytokine that is commonly expressed following tissue injury. TNF-α expression not only promotes inflammation but can also lead to pain hypersensitivity in nociceptors. With the established link between TNF-α and inflammatory pain, we identified its increased expression in the teeth of patients affected with caries and pulpitis. We generated a transgenic mouse model (TNF-α(glo)) that could be used to conditionally overexpress TNF-α. These mice were bred with a dentin matrix protein 1 (DMP1)-Cre line for overexpression of TNF-α in both the tooth pulp and bone to study oral pain that would result from subsequent development of pulpitis and bone loss. The resulting DMP1/TNF-α(glo) mice show inflammation in the tooth pulp that resembles pulpitis while also displaying periodontal bone loss. Inflammatory infiltrates and enlarged blood vessels were observed in the tooth pulp. Pulpitis and osteitis affected the nociceptive neurons innervating the orofacial region by causing increased expression of inflammatory cytokines within the trigeminal ganglia. With this new mouse model morphologically mimicking pulpitis and osteitis, we tested it for signs of oral pain with an oral function assay (dolognawmeter). This assay/device records the time required by a mouse to complete a discrete gnawing task. The duration of gnawing required by the DMP1/TNF-α(glo) mice to complete the task was greater than that for the controls; extended gnaw time in a dolognawmeter indicates reduced orofacial function. With the DMP1/TNF-α(glo) mice, we have shown that TNF-α expression alone can produce inflammation similar to pulpitis and osteitis and that this mouse model can be used to study dental inflammatory pain.