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Aim: This prospective in vivo study aimed to optimize the assessment of pulpal contrast‐enhancement (PCE) on dental magnetic resonance imaging (dMRI) and investigate physiological PCE patterns. Methodology: In 70 study participants, 1585 healthy teeth were examined using 3‐Tesla dMRI before and after contrast agent administration. For all teeth, the quotient of post‐ and pre‐contrast pulp signal intensity (Q‐PSI) was calculated to quantify PCE. First, pulp chambers were analysed in 10 participants to compare the coefficient of variation of mean versus maximum Q‐PSI values (Q‐PSImean versus Q‐PSImax). Second, dynamic PCE was evaluated in 10 subjects to optimize the time interval between contrast agent application and image acquisition. Finally, 50 participants (age groups: 20–29, 30–39, 40–49, 50–59 and 60–69 years) were examined to analyse age, gender, tooth types and maxilla versus mandible as independent factors of PCE. Statistical analysis was performed using Wilcoxon signed rank test and linear mixed models. Results: PCE assessment based on Q‐PSImax was associated with a significantly smaller coefficient of variation compared with Q‐PSImean, with median values of 0.17 versus 0.21 (p =.002). Analysis of dynamic PCE revealed an optimal timing interval for image acquisition 4 min after contrast media application. No significant differences in PCE were observed by comparing age groups, female versus male participants and maxillary versus mandibular teeth (p >.05). Differences between tooth types were small (median Q‐PSImax values of 2.52/2.32/2.30/2.20 for molars/premolars/canines/incisors) but significant (p <.05), except for the comparison of canines versus premolars (p =.80). Conclusions: PCE in dMRI was a stable intra‐individual marker with only minor differences between different tooth types, thus forming an important basis for intra‐individual controls when assessing teeth with suspected endodontic pathosis. Furthermore, it was demonstrated that PCE is independent of age, gender and jaw type. These findings indicate that dMRI‐based PCE analysis could be a valuable diagnostic tool for the identification of various pulp diseases in future patient studies. [ABSTRACT FROM AUTHOR]

Aim: To investigate attitudes and approaches of UK primary care dentists to carrying out vital pulp treatment (VPT) after carious exposure and with additional signs and symptoms indicative of irreversible pulpitis. Methodology: An electronic questionnaire was openly distributed via publicly funded (NHS) local dental committees, corporate dental service‐providers, professional societies and social media. Principally NHS practitioners and those from mixed and private practice were targeted, in addition to community and military dental officers, and dental therapists. Participants were asked questions relating to several clinical scenarios, with responses analysed using descriptive statistics. χ2 tests with sequential Bonferroni correction were used to explore variables including the method of remuneration, practitioner type (dentist/therapist), postgraduate qualification(s), place of graduation and years since qualification. Variables with a relationship p ≤.2 were selected for backwards likelihood ratio logistic modelling. Results: In total, 648 primary care practitioners were included for analysis. Calcium hydroxide (CH) was most frequently used for direct pulp caps (DPCs) (398/600; 66.3%) with calcium silicate cements (CSCs) less frequently used (119/600; 19.8%). Rubber dam was used by 222/599 (37.1%) practitioners. A definitive pulpotomy for the management of teeth with signs and symptoms indicative of irreversible pulpitis was selected by 65/613 (10.6%) dentists. The principal barrier for the provision of definitive pulpotomies was a lack of training (602/612; 98.4%). Regression analysis identified NHS practitioners as a good predictor for using CH for DPCs, having shorter emergency appointments, limited access to magnification and not using rubber dam. Non‐UK graduates were more likely to select CSCs, appropriately control pulpal haemorrhage, undertake appropriate postoperative evaluation and use rubber dam. Conclusions: Practitioners deviated from evidence‐based guidelines in a number of aspects including material selection, asepsis and case selection. A number of other challenges exist in primary care in providing predictable VPTs, including lack of time and access to magnification. These were most evident in NHS practice, potentially exacerbating existing social health inequalities. Possible inconsistencies in the UK undergraduate curriculum were supported by a lack of association between years since qualification and technique employed as well as the fact that non‐UK graduates and dentists with postgraduate qualifications adhered more to evidence‐based VPT guidelines. [ABSTRACT FROM AUTHOR]

Aim: To investigate current approaches and attitudes towards the management of deep caries in primary dental care within the United Kingdom (UK). Methodology: Open distribution of an electronic questionnaire survey was undertaken to primary care dental professionals working in publicly funded National Health Service [NHS], privately funded, military and community dental services. Demographic variables investigated included the following: place of qualification, method of remuneration, level of restorative training, materials available, years qualified, appointment length and clinician type. Management variables focussed on case‐based scenarios. Univariate analyses of responses to questions were undertaken using χ2 tests with sequential Bonferroni correction. Variables with a statistical relationship of p ≤.2 were selected for binary logistic regression modelling. Results: A total of 657 responses were received. Practitioners with formal postgraduate qualifications (PGQ) were more likely (OR, 95%CI) to undertake further tests to aid diagnosis including: gaining a patient history (1.80, 1.01–3.20), periapical radiography (1.43, 1.01–2.03), cold pulp testing (2.079, 1.46–2.97) and electric pulp testing (1.65, 1.02–2.65). Rubber dam was infrequently used for deep caries management (29.2%). Non‐NHS practitioners were much more likely to use rubber dam (3.40, 2.15–5.37), as were those that had completed PGQ (2.24, 1.48–3.38). Non‐selective caries removal was used in deep caries by 41.4% of practitioners. Indirect pulp caps were carried out by 56.7% of practitioners. NHS practitioners were more likely to place calcium hydroxide (3.74, 1.97–7.15), whilst non‐NHS practitioners were more likely to place calcium silicate cements (CSCs) (3.303, 1.71–6.38) as were non‐UK graduates (5.63, 2.47–12.86) and those with PGQ (2.12, 1.17–3.87). Conclusions: This UK survey highlights significant variation in the management of deep caries. There is lack of consensus regarding the use of a standard systematic approach to diagnosing disease, with a reliance on history and tests with poor specificity. Non‐selective caries removal for managing deep carious lesions remains common, with low rubber dam compliance underlining a lack of asepsis. Notably, a significant number of practitioners placed indirect pulp caps, but CSCs and GIC were not commonly used. At present, although clear guidelines are available this is not translating into consistent management approaches in practice, suggesting that better dissemination of current treatments is essential to undergraduate and postgraduate groups. [ABSTRACT FROM AUTHOR]

Background: Stem/progenitor cell‐mediated pulpal regeneration could represent a promising therapeutic alternative in the field of clinical endodontics. Aim: The present study aimed to systematically assess and meta‐analyse dental pulpal tissue regeneration, pulpal vitality and apical healing after the transplantation of stem/progenitor cells versus no transplantation. Data sources: MEDLINE, Cochrane CENTRAL and EMBASE were searched up to January 2019 for animal experiments and human trials evaluating the pulpal transplantation of stem/progenitor cells. Cross‐referencing and hand search were additionally performed. Study eligibility criteria, participants and interventions: Based on randomized controlled clinical trials (RCTs) or controlled clinical trials (CCTs), conducted in animals or humans, the effect of the transplantation of stem/progenitor cells compared to no transplantation on pulpal tissue regeneration, pulpal vitality and apical healing was examined. Study appraisal and synthesis methods: The primary outcome was histologically determined pulpal tissue regeneration, whilst pulpal vitality and apical healing were secondary outcomes. The SYstematic Review Centre for Laboratory animal Experimentation (SYRCLE) guidelines and the revised Cochrane risk of bias tool (RoB 2.0) were used for risk‐of‐bias assessment. Pooled standardized differences in means (SDM) and 95% confidence intervals (95% CI) were calculated using random‐effects meta‐analyses. Results: From 2834 identified articles, eight animal experiments (82 animals with 336 experimental pulpal defects) and one human trial (40 humans with 40 pulpal defects) were included. Risk of bias of most animal studies was high, whilst the human trial revealed 'some concerns'. Stem/progenitor cell‐transplanted pulps demonstrated significantly increased pulpal tissue regeneration compared with controls (SDM [95%CI]: 6.29 [3.78–8.80]). Limitations: Data on pulpal vitality and apical healing were sparse and inconsistent. Heterogeneity across studies was substantial, publication bias was present, and mainly indirect, surrogate outcome measures were applied. The overall strength of evidence was very low. Conclusions and implications of key findings: The transplanation of stem/progenitor cells shows promise for pulp regeneration, whilst clinical routine application is still not in reach. Further investigations, employing a comprehensive set of outcomes including those demonstrating functional pulp regeneration relevant for patient‐centred care, are required. [ABSTRACT FROM AUTHOR]

Aim To summarize the collective in vitro, in vivo and clinical evidence of the involvement of the receptor activator of NF-κ B ligand ( RANKL)-osteoprotegerin ( OPG) system, a system of two molecules controlling osteoclast differentiation and hard-tissue resorption, in pulpal and periapical pathophysiology. Methodology A systematic search related to RANKL and/or OPG and pulp or periapical disease was conducted on Medline, Biosis, Cochrane, Embase and Web of Science databases using keywords and controlled vocabulary. No language restriction was applied. Two independent reviewers first screened titles and abstracts and then the full texts that were initially included. The reference lists of the identified publications were examined for additional titles. Results A total of 33 papers were identified. In vitro studies ( N = 11) revealed that pulpal cells can be stimulated by various inflammatory agents to produce RANKL, whilst many studies did not consider the RANKL/ OPG ratio. Animal studies ( N = 9) mostly focused on the time course and development of periapical lesions in relation to the RANKL- OPG system. Levels of RANKL and OPG in the necrotizing pulp were not investigated. Human studies ( N = 13) showed a steady-state expression of OPG in the odontoblast layer. Conflicting results have been reported regarding the role of RANKL in active apical periodontitis, again because the correlation of this molecule with its inhibitor ( OPG) was often disregarded. Conclusions There is relatively little information currently available that would highlight the specific role of RANKL and OPG in pulpal and periapical disease. OPG may play a protective role against internal resorption, whilst an increased periapical RANKL/ OPG ratio might indicate bone resorption. [ABSTRACT FROM AUTHOR]

Smith JG, Smith AJ, Shelton RM, Cooper PR. Antibacterial activity of dentine and pulp extracellular matrix extracts. International Endodontic Journal, 45, 749-755, 2012. Abstract Aim To determine whether extracellular matrix (ECM) preparations from pulp (pECM) and dentine (dECM) possess antimicrobial activity. Methodology Dentine and pulp ECM preparations were isolated with 10% ethylenediaminetetraacetic acid (EDTA), pH 7.2 and sequential use of 0.5 mol L−1 NaCl, pH 11.7 and 0.1 mol L−1 tartaric acid, pH 2.0, respectively, with protease inhibitor inclusion throughout. Antimicrobial activity against Streptococcus mutans, Streptococcus oralis and Enterococcus faecalis was assessed using turbidity as a measure of bacteria growth. The cytotoxicity of the extracts on primary pulp cells was also determined by lactate dehydrogenase (LDH) release. Statistical analysis of data was performed using paired student's t-tests. Results Extracellular matrix extracts from the pulp and dentine showed antibacterial activity against three types of anaerobic bacteria associated with dental disease ( P < 0.05). The ECM extracts demonstrated no significant cytotoxic effect on pulpal cells at the concentrations used for antibacterial activity. Conclusions The bacteriostatic antibacterial activity of pECM and dECM indicates that the release of these matrix molecules from pulp and dentine may contribute to defence responses during dental disease, treatment and repair. [ABSTRACT FROM AUTHOR]

Laurent P, Camps J, About I. Biodentine™ induces TGF- β1 release from human pulp cells and early dental pulp mineralization. International Endodontic Journal, 45, 439-448, 2012. Abstract Aim To assess the ability of a recently developed tricalcium silicate-based cement (Biodentine™) to induce reparative dentine synthesis and to investigate its capacity to modulate pulp cells TGF- β1 secretion. Methodology Biodentine™ was directly applied onto the dental pulp in an entire human tooth culture model. After various culture periods, the interaction of the material with dental pulp tissue was analysed on tissue sections. The effect of increasing surface area of this material on TGF- β1 secretion was investigated on pulp cell cultures and compared with that of MTA, calcium hydroxide and Xeno®III adhesive resin. After performing artificial injuries on pulp cell cultures, the materials eluates were added for 24 h and then TGF- β1 secretion was quantified by ELISA. Controls were performed by incubating intact cells with the culture medium, while injured cells TGF- β1 level was used as the baseline value. Results Biodentine™ induced mineralized foci formation early after its application. The mineralization appeared under the form of osteodentine and expressed markers of odontoblasts. Biodentine™ significantly increased TGF- β1 secretion from pulp cells ( P < 0.03) independently of the contact surface increase. This increase was also observed with calcium hydroxide and MTA, but not with the resinous Xeno®III. The statistical analysis showed statistically significant differences between capping materials and the resinous Xeno®III ( P < 0.001). Conclusions When Biodentine™ was applied directly onto the pulp, it induced an early form of reparative dentine synthesis, probably due to a modulation of pulp cell TGF- β1 secretion. [ABSTRACT FROM AUTHOR]

Jafarzadeh H, Abbott PV. Review of pulp sensibility tests. Part Ι: general information and thermal tests. International Endodontic Journal, 43, 738–762, 2010. A major, and essential, part of the diagnostic process for pulp disease is the use of pulp sensibility tests. When diagnosing pulp pain, these tests can be used to reproduce the symptoms reported by the patient to diagnose the diseased tooth as well as the disease state. However, a major shortcoming with these tests is that they only indirectly provide an indication of the state of the pulp by measuring a neural response rather than the vascular supply, so both false positive and false negative results can occur. The relevant literature on pulp sensibility tests in the context of endodontics up to January 2009 was reviewed using PubMed and MEDLINE database searches. This search identified papers published between November 1964 and January 2009 in all languages. Thermal tests have been used as an integral part of dental examinations. Two types of thermal tests are available, one uses a cold stimulus and the other uses a hot stimulus, and each has various methods of delivery. If these tests are used properly, injury to the pulp is highly unlikely. A review of the literature regarding the rationale, indications, limitations, and interpretation of thermal tests, the value of these diagnostic tests, as well as a discussion of the important points about each of these tests is presented. [ABSTRACT FROM AUTHOR]

Ansari G, Ranjpour M. Mineral trioxide aggregate and formocresol pulpotomy of primary teeth: a 2-year follow-up. International Endodontic Journal, 43, 413–418, 2010. Aim To compare the clinical and radiographic response of primary teeth to vital pulpotomy using mineral trioxide aggregate (MTA) or formocresol (FC). Methodology A group of 17 children aged 4–9 were selected from those referred to the Paedodontic Department at Shahid Beheshti University, Dental School. Cases with at least two matching teeth were selected (40 teeth), showing signs of pulp involvement. A pulpotomy procedure was carried out in all cases with FC in control teeth whilst MTA was placed in experimental teeth. Clinical and radiographic evaluations were performed at 1-, 6-, 12- and 24-month recall. Statistical analysis using a Fischer exact test was performed on the data to determine significant differences between the groups. Results Overall, 22 second and 18 first primary molars were included. The gender ratio was one male to three female. No significant difference was found between the clinical and radiographic outcomes of the two groups at 6-, 12- and 24-month follow-up ( P > 0.05). Internal resorption was seen significantly more often in FC cases after 12 months than MTA cases. Overall radiographic appearance of normal structures at 24th month was seen in more than 95% of the cases in MTA and 90% in the FC-treated group ( P > 0.05). Conclusion Mineral trioxide aggregate for pulp treatment of primary teeth can be considered a replacement for FC. [ABSTRACT FROM AUTHOR]

Aim To determine the prevalence of pulp stones in a group of patients using radiographs, and to assess any associations with age, gender, systemic diseases, tooth type, jaw, caries, restorations, impacted third molars and dental anomalies including dens invaginatus, taurodontism, dens evaginatus and microdontia. Methodology A total of 519 patients were selected randomly amongst patients referred to Oral Diagnosis and Radiology Department, Faculty of Dentistry, Ankara University. After clinical inspection, full-mouth periapical radiographs were obtained. An oral radiologist examined the radiographs to identify pulp stones. Frequency distribution of teeth with pulp stones was calculated and statistical analysis was performed with chi-square test. Results Of the patients, 313 (60%) were female and 206 (40%) were male. Sixty (12%) had one or more teeth that contained pulp stones. Amongst the 13 474 teeth examined radiographically, 627 (5%) had pulp stones. There was no significant association between pulp stone occurrence and gender or systemic diseases. As age increased, the prevalence of pulp stones increased ( P < 0.01). Molars had statistically more pulp stones than premolars and incisors ( P < 0.001). Frequencies in both maxillary and mandibular jaw were similar. There was no association between pulp stones and impacted third molars, caries, restorations or dental anomalies. Conclusions The prevalence of pulp stones increased with age and was significantly higher in molar teeth than premolars and incisors. There was no significant association between pulp stones and gender, systemic diseases, impacted third molars, condition of the crown and dental anomalies. [ABSTRACT FROM AUTHOR]

Aim To compare oncostatin M (OSM) expression in clinically healthy and inflamed specimened human pulp tissue. Methodology Thirty pulpal tissue specimens (15 clinically healthy and 15 inflamed) were obtained from extracted third molars with informed consent from patients. The levels of OSM were compared between clinically healthy pulp and inflamed pulp tissues using the semi-quantitative reverse-transcriptase polymerase chain reaction. In addition, immunohistochemistry was used to identify the in situ localization of OSM expression in pulp specimens. For testing of differences in the OSM between the clinically healthy and inflamed human dental pulps, the Wilcoxon–Mann–Whitney rank sum test was applied. Differences in OSM expression between tissue with low and high levels of inflammation were subsequently analysed by Fisher’s exact test. Results Inflamed pulps exhibited significantly higher OSM mRNA gene expression than clinically healthy pulps ( P < 0.05). Immunohistochemistry demonstrated that OSM expression was significantly higher in inflamed than clinically healthy pulps ( P < 0.05). OSM staining was detected in odontoblasts, fibroblasts, inflammatory infiltrates and endothelial cells. Conclusions Oncostatin M expression was elevated in inflamed pulp tissue. OSM is potentially involved in the disease process of pulpal inflammation. [ABSTRACT FROM AUTHOR]

Vascular supply is the most accurate marker of pulp vitality. Tests for assessing vascular supply that rely on the passage of light through a tooth have been considered as possible methods for detecting pulp vitality. Laser Doppler flowmetry (LDF), which is a noninvasive, objective, painless, semi-quantitative method, has been shown to be reliable for measuring pulpal blood flow. The relevant literature on LDF in the context of endodontics up to March 2008 was reviewed using PubMed and MEDLINE database searches. This search identified papers published between June 1983 and March 2008. Laser light is transmitted to the pulp by means of a fibre optic probe. Scattered light from moving red blood cells will be frequency-shifted whilst that from the static tissue remains unshifted. The reflected light, composed of Doppler-shifted and unshifted light, is returned by afferent fibres and a signal is produced. This technique has been successfully employed for estimating pulpal vitality in adults and children, differential diagnosis of apical radiolucencies (on the basis of pulp vitality), examining the reactions to pharmacological agents or electrical and thermal stimulation, and monitoring of pulpal responses to orthodontic procedures and traumatic injuries. Assessments may be highly susceptible to environmental and technique-related factors. Nonpulpal signals, principally from periodontal blood flow, may contaminate the signal. Because this test produces no noxious stimuli, apprehensive or distressed patients accept it more readily than current methods of pulp vitality assessment. A review of the literature and a discussion of the application of this system in endodontics are presented. [ABSTRACT FROM AUTHOR]

Aim To use immunocytochemistry for determining the expression of HCN1, HCN2 and HCN3 (three subunits of the hyperpolarization-activated cyclic nucleotide-gated current channel) in rodent trigeminal ganglia (TG) that innervate healthy teeth and determine if expression of HCN subunits is increased in TG following pulp exposure. Methodology Pulps were exposed in right maxillary incisors of male Sprague-Dawley rats. After fixation, TG were removed, cryostat sectioned, and immunocytochemistry was utilized to study the expression of HCN1-3 subunits. Immunoreactivity of individual neurons from the maxillary region of the TG was determined with ImageJ software. Differences in the number immunopositive neurons amongst groups were tested for statistical significance with either a Yates or Pearson’s chi-square or Fisher’s exact probability tests depending on neuron sample size. Differences in the intensity of immunoreactivity between groups were tested for statistical significance with a Student’s t-test. Results The majority of TG neurons were immunopositive for HCN1-3. Moreover, statistically significant increases in the number of TG neurons immunopositive for HCN1 and the intensity of HCN1-3 immunoreactivity were observed within hours of exposing the tooth pulp. Conclusions HCN1-3 expression, as determined by immunocytochemistry, is increased within hours after injury. Given that Ih can facilitate neuronal excitability, results of the current study suggest that antagonists to HCN1-3 subunits could work as analgesics in the alleviation of orofacial pain. [ABSTRACT FROM AUTHOR]

Aim To determine the effect of matrix metalloproteinase (MMP) inhibition on periapical lesion formation in a rat model. Methodology The pulp chambers of mandibular fist molars of adult SD rats were exposed to be infected by oral microbes. The experimental group was fed 20 mg kg−1 MMP-inhibitor chemically modified tetracycline-3 (CMT-3) daily in an oral gavage and the controls were fed the vehicle. After 2 and 4 weeks, the mandibles ( n = 10 in both groups at both times) were radiographed, decalcified and subjected to histological analysis. Extension of necrosis in first molar distal root canals was measured from the histological sections, and periapical lesion sizes in the same roots were determined from radiographs and histological sections. Mann–Whitney U-test was used for the statistical analysis. Results There was a statistically significant difference in the extension of necrosis in root canals between 2 and 4 weeks in the control group ( P < 0.05), but not with MMP inhibition. Radiographically, MMP inhibition increased the periapical lesion size by 70% and 34% after 2 and 4 weeks respectively ( P < 0.05 in after 2 weeks). In histological measurements, lesion size increased with MMP inhibition by 26% and 8% after 2 and 4 weeks respectively. Conclusions MMP inhibition affects pulpal and periapical inflammation, increasing the rate of spreading of necrosis in root canals and the rate of periapical lesion formation. [ABSTRACT FROM AUTHOR]

Krage TL, Stiefel A, Stephan BM, Zimmer S, Lambrichts I, Raab WH-M. Microhardness changes in dentine after neonatal capsaicin application. International Endodontic Journal, 38, 570–574, 2005. To determine if desensitization of the nociceptive innervation in the dental pulp has an effect on odontoblast function in the rat. Neonatal systemic application of capsaicin was used to selectively eliminate nociceptive innervation. 12 capsaicin-treated rats were intravitally perfused at 150 days of life with 4% formaldehyde and jaws were prepared for Vicker's microhardness (VMH) measurement. As a control, 12 rats were injected with vehicle on the 3rd day of life and intravital perfusion was carried out exactly as those used for the experimental group. Immunohistological labeling of CGRP was carried out in both groups to assure the efficiency of desensitization in the experimental group. The VMH was measured in the incisors of each animal for a quantitative analysis of dentine quality. Vicker's microhardness was significantly higher in the control rats compared with the capsaicin-treated rats ( P < 0.001). Neonatal systemic application of capsaicin produces changes in the quality of dentine in the rat over time and therefore it is suggestive that selective elimination of the nociceptive innervation in pulpal tissue may effect odontoblast function. [ABSTRACT FROM AUTHOR]

Huang F-M, Tsai C-H, Chen Y-J, Liu C-M, Chou M-Y, Chang Y-C.Upregulation of tissue-type plasminogen activator in inflamed human dental pulps.International Endodontic Journal,38, 328–333, 2005.To compare tissue-type plasminogen activator (t-PA) expression in normal human pulp and inflamed human pulp tissue specimens.Thirty pulpal tissue specimens (13 normal and 17 inflamed pulps) were obtained from extracted third molars. The levels of t-PA between normal pulp and inflamed pulp tissues were compared using the quantitative reverse-transcriptase polymerase chain reaction analysis. In addition, immunohistochemistry was used to identify thein situlocalization of t-PA expression in pulp specimens. Wilcoxon–Mann–Whitney rank sum test was applied for the statistical analysis of the results.t-PA mRNA gene was found more in inflamed pulps when compared with normal pulp tissue (P < 0.05). The results from immunohistochemistry demonstrated that t-PA expression was significantly higher in the inflamed pulp (P = 0.025). t-PA stain was detected in the fibroblasts, inflammatory infiltrates and endothelial cells.t-PA expression was significantly higher in inflamed pulp tissue. t-PA may play an important role in the pathogenesis of pulpal inflammation. [ABSTRACT FROM AUTHOR]

Benetti AR, Valera MC, Mancini MNG, Miranda CB, Balducci I. In vitro penetration of bleaching agents into the pulp chamber. International Endodontic Journal, 37, 120–124, 2004. To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures. Bovine lateral incisors were sectioned 3 mm apical to the cemento-enamel junction and the coronal pulpal tissue was removed. Teeth were divided into six groups ( n = 10): G1, G2 and G3 were not submitted to any restorative procedure, while G4, G5 and G6 were submitted to Class V preparations and restored with composite resin. Acetate buffer was placed in the pulp chamber and treatment agents were applied for 60 min at 37 °C as follows: G1 and G4, immersion into distilled water; G2 and G5, 10% carbamide peroxide (CP) exposure; G3 and G6, 35% CP bleaching. The buffer solution was removed and transferred to a glass tube where leuco crystal violet and horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined spectrophotometrically at 596 nm. A standard curve made with known amounts of hydrogen peroxide was used to convert the optical density values of the coloured samples into microgram equivalents of hydrogen peroxide. Data were submitted to anova and Tukey's test (5%). Amounts of hydrogen peroxide found in the pulp chamber of G2 and G5 specimens (0.1833 ± 0.2003 µg) were significantly lower ( P = 0.001) when compared to G3 and G6 specimens (0.4604 ± 0.3981 µg). Restored teeth held significantly higher ( P = 0.001) hydrogen peroxide concentrations in the pulp chamber than intact teeth. Higher concentrations of the bleaching agent produced higher levels of hydrogen peroxide in the pulp chamber, especially in restored teeth. [ABSTRACT FROM AUTHOR]

Okino LA, Siqueira EL, Santos M, Bombana AC, Figueiredo JAP. Dissolution of pulp tissue by aqueous solution of chlorhexidine digluconate and chlorhexidine digluconate gel. International Endodontic Journal, 37, 38–41, 2004. To evaluate the activity of various root canal irrigants on bovine pulp tissue. The irrigants tested were: 0.5, 1.0 and 2.5% sodium hypochlorite; 2% aqueous solution of chlorhexidine digluconate; 2% chlorhexidine digluconate gel (Natrosol™); and distilled water as control. Bovine pulp fragments were weighed and placed in contact with 20 mL of each tested substance in a centrifuge at 150 r.p.m. until total dissolution. Dissolution speed was calculated by dividing pulp weight by dissolution time. Statistical analysis was performed using the Kruskal–Wallis test. Distilled water and both solutions of chlorhexidine did not dissolve the pulp tissue within 6 h. Mean dissolution speeds for 0.5, 1.0 and 2.5% sodium hypochlorite solutions were 0.31, 0.43 and 0.55 mg min−1, respectively. The solvent ability of chlorhexidine solutions was similar to that of distilled water. The results for sodium hypochlorite solutions, chlorhexidine solutions and distilled water were statistically different ( P > 0.01). Both chlorhexidine preparations and distilled water were not able to dissolve pulp tissue. All sodium hypochlorite solutions were efficient in dissolving pulp tissue; the dissolution speed varied with the concentration of the solution. [ABSTRACT FROM AUTHOR]

Costa CAS, Oliveira MF, Giro EMA, Hebling J. Biocompatibility of resin-based materials used as pulp-capping agents. International Endodontic Journal, 36, 831–839, 2003. To evaluate and compare the response of pulps of rats capped with resin-modified glass-ionomer cement (RMGIC) or self-etching adhesive system. Class I cavities were prepared on the occlusal surface of 54 maxillary first molars of 27 rats. Pulp exposure was performed on the cavity floor. The following resin-based materials were applied as pulp-capping agents: G1, Clearfil Liner Bond 2V (CLB 2V; Kuraray Co., Japan); G2, Vitrebond (VIT; 3M/ESPE, USA). In group 3 (control group), a calcium hydroxide/saline paste (CH; Labsynth, Brazil) was used. The cavities were restored with amalgam. After 7, 30 and 60 days, the animals were sacrificed and the jaws were processed for microscopic evaluation. Despite the inflammatory response caused by the experimental and the control materials at 7 days, pulpal healing associated with calcified barrier formation was observed at 60 days following the pulp therapy. Both resin-based materials promoted a large zone of cell-rich fibrodentine matrix deposition on the pulp horn related to the pulp exposure site, which was larger to VIT than to CLB 2V specimens. Tertiary dentine underneath the fibrodentine matrix was deposited by a layer of elongated pulpal cells. The remaining pulpal tissue exhibited normal histological characteristics. In the control group, healing and dentine-bridge formation was observed at 30 days. Pulpal breakdown occurred only when bacterial infection occurred. Both experimental pulp-capping agents allowed pulpal healing characterized by cell-rich fibrodentine and tertiary dentine deposition as well as calcified barrier formation. [ABSTRACT FROM AUTHOR]

Abstract Aim To test the null hypothesis that removal of pulp tissue and predentine from root canals of multirooted teeth is not significantly different when performed by one of two mechanical preparation techniques in conjunction with either water or 3% sodium hypochlorite (NaOCl) irrigation. Methodology Forty-six freshly extracted premolar or molar teeth, with pulps vital at the time of extraction, were assigned to four groups balanced by anatomy (group 1, step-back filing/NaOCl; group 2, step-back filing/water; group 3, automated rotary/NaOCl; group 4, automated rotary/water). Preparation was undertaken by a single operator and the volumes of irrigant recorded for each tooth. One root from each tooth was prepared for transverse histological assessment at eight levels, including one at and two apical to the working length. A validated index was used to measure the presence and location of residual pulp tissue and predentine. Results No statistically significant differences were found in the frequency with which residual pulp tissue or predentine were observed amongst the groups. Coronal parts were more frequently devoid of pulp tissue and predentine than the apical. Canals were frequently occluded with residual pulp tissue apical to the working length. There was a trend for better pulp and predentine removal in accessible parts of the canal as a function of rotary preparation and NaOCl irrigation. The isthmus had residual pulp tissue less frequently in the NaOCl groups. Accessory anatomy was unaffected regardless of technique or irrigant. Conclusions Pulp tissue and predentine removal were not significantly different between a step-back filing and an automated rotary preparation technique in conjunction with water or NaOCl. [ABSTRACT FROM AUTHOR]

Literature review There is a paucity of information on the concise relationship between endodontics and orthodontics during treatment planning decisions. This relationship ranges from effects on the pulp from orthodontic treatment and the potential for resorption during tooth movement, to the clinical management of teeth requiring integrated endodontic and orthodontic treatment. This paper reviews the literature based on the definition of endodontics and the scope of endodontic practice as they relate to common orthodontic-endodontic treatment planning challenges. Literature data bases were accessed with a focus on orthodontic tooth movement and its impact on the viability of the dental pulp; its impact on root resorption in teeth with vital pulps and teeth with previous root canal treatment; the ability to move orthodontically teeth that were endodontically treated versus nonendodontically treated; the role of previous tooth trauma; the ability to move teeth orthodontically that have been subjected to endodontic surgery; the role of orthodontic treatment in the provision for and prognosis of endodontic treatment; and, the integrated role of orthodontics and endodontics in treatment planning tooth retention. Orthodontic tooth movement can cause degenerative and/or inflammatory responses in the dental pulp of teeth with completed apical formation. The impact of the tooth movement on the pulp is focused primarily on the neurovascular system, in which the release of specific neurotransmitters (neuropeptides) can influence both blood flow and cellular metabolism. The responses induced in these pulps may impact on the initiation and perpetuation of apical root remodelling or resorption during tooth movement. The incidence and severity of these changes may be influenced by previous or ongoing insults to the dental pulp, such as trauma or caries. Pulps in teeth with incomplete apical foramen, whilst not immune to adverse sequelae during tooth movement, have a reduced... [ABSTRACT FROM AUTHOR]

Human dental pulp fibroblast strains were established from explants of dental pulps using identical culture techniques. To determine proliferative activity, a 3H-thymidine uptake and a crystal violet dye-binding assay were performed at passage numbers seven and eight. Assays were performed in the presence of either 0% fetal calf serum (FCS), 0.2% FCS or 10% FCS. Considerable variation in the overall proliferative activity of the different pulp cell strains (when averaged over all other variables) was noted. All dental pulp cell strains demonstrated significantly different proliferative activity from each other. In addition, the level of proliferative response and 3H-thymidine incorporation decreased as the passage number of the cells increased. This was in accordance with the findings of Tardieu-Moreau et al. (1992). It is proposed that the differences in proliferative activity are most likely attributable to inherent variability within the established pulp cell strains. Platelet derived growth factor-BB (PDGF-BB) and insulin-like growth factor-1 (IGF-1) were added to the human pulp cells both separately and in combination. All of the pulp cells exhibited increased proliferative activity in the presence of the growth factors with the combination of PDGF-BB/IGF-1 having the greatest mitogenic effect. There was also significant variability in the level of response of all pulp cell strains to the different growth factors. This study identified significant variability in the responsiveness to the growth factors between the pulp cell strains when the results of the 3H-thymidine and dye binding assays were compared. These findings reinforce the thesis that different assay procedures may also influence the findings of biological investigations involving the human dental pulp. The results of this study confirm that when comparing the findings of different in vitro studies involving human pulp cells, variations in experimental data can be strongly influenced by the pulp cell strain used and the culture technique employed. Indeed, studies of human pulp cell proliferation using pulp cells which are not of the same transfer number may not be relevant. [ABSTRACT FROM AUTHOR]

The proteoglycans synthesized by fibroblasts derived from healthy human adult dental pulps have been isolated and characterized on the basis of their glycosaminoglycan content, molecular size and charge. The proteoglycans were identified by their labelling with [35S] sulphate and susceptibility to digestion by papain. The sulphated glycosaminoglycans associated with the proteoglycans were identified following specific enzymatic and chemical degradations as chondroitin sulphate, dermatan sulphate and heparan sulphate. Dermatan sulphate and chondroitin sulphate were identified as the major glycosaminoglycans secreted into the medium, whereas chrondroitin sulphate and heparan sulphate were the principal glycosaminoglycans associated with the cell layers. The proteoglycans could be fractionated on the basis of their charge and size into a number of heterogeneous pools. The principal proteoglycans isolated were small and contained either chondroitin sulphate or dermatan sulphate and most likely correspond to decorin and biglycan. Other molecules with features similar to versican and syndecan were also identified. [ABSTRACT FROM AUTHOR]