The role of infection in signalling root resorption: A narrative review.

BACKGROUND: Root resorption consists of complex, multistep processes that involve cell signalling caused by inflammation and stromal cells, which promotes the secretion of receptor activator of nuclear factor κB ligand/ macrophage-colony stimulating factor (RANKL/M-CSF) resulting in a resorptive process. OBJECTIVE: The aim of this narrative review was to analyse the literature related to root resorption resulting from microbial infection and to comparing it with non-microbial infection. METHODS: An electronic literature search was performed using the PubMed database and applying keywords of articles published in English. Eligible papers were reviewed to reveal the descriptions of bone and root resorption processes. The abstracts were searched manually to identify articles about infection-stimulating bone and root resorption. RESULTS: Three main types of root resorption were identified, two associated with primary bacterial infection and one secondary to bacterial infection. These include external inflammatory resorption, internal inflammatory resorption and external cervical (invasive) resorption. DISCUSSION: The magnitude of cytokine involvement that promotes resorption and M-CSF/RANKL production depends on multiple factors, including pathogen virulence, site of infection and host genetic factors that activate the inflammation at the infection site. Two mechanisms activate the resorption mechanisms-the canonical and non-canonical pathways that can activate clastic cells independently of the RANKL/RANK canonical pathways. CONCLUSIONS: Two pathways of root resorption co-exist in the body. When resorption is caused by infection, chronic inflammation due to bacterial infection prolongs the secretions of pro-inflammatory cytokines that intensify root and bone resorption. The second pathway is bacterial independent of the non-infection root resorption that is part of the wound healing process, which is limited in time due to its innate ability.

Impact of root canal treatment on high-sensitivity C-reactive protein levels in systemically healthy adults with apical periodontitis - a preliminary prospective, longitudinal interventional study.

AIM: To assess the influence of root canal treatment on serum high-sensitivity C-reactive protein (hsCRP) levels in systemically healthy human adults. METHODOLOGY: Fifteen individuals aged 20-40 years diagnosed with apical periodontitis [Periapical Index (PAI) score ≥3] who were otherwise healthy took part in this prospective interventional study. Patients with moderate to severe periodontitis, systemic diseases and traditional cardiac risk factors (hypertension, diabetes, dyslipidemia and smoking) were excluded. Root canal treatment was completed in two visits with an inter-appointment calcium hydroxide intracanal medicament. After 6 months, healing of apical periodontitis was evaluated clinically and radiographically, and serum hsCRP levels were recorded. A paired sample T-test was used to compare the mean hsCRP values between the pre- and post-treatment groups. The Mann-Whitney U test was used to compare hsCRP values between patients with PAI scores of 3 and 4, and the Wilcoxon signed-rank test was used to compare pre- and postoperative PAI scores. RESULTS: The mean preoperative baseline serum hsCRP level was 2.88 ± 1.06 mg L-1 which can be associated with a moderate risk for cardiovascular disease (CVD). Based on the preoperative hsCRP levels, eight of the 15 patients were categorized as high risk (hsCRP > 3 mg L-1 ) and the other seven as medium risk (hsCRP 1-3 mg L-1 ) for CVD. The mean preoperative hsCRP value of patients with a PAI score of 3 was 2.88 ± 1.19 mg L-1 , and the mean preoperative hsCRP of patients with a PAI score of 4 was 2.87 ± 0.15 mg L-1 , which was not significantly different (P = 0.942). Six months after root canal treatment, the mean PAI score had significantly reduced from 3.2 ± 0.42 to 1.4 ± 0.69 (P = 0.003). The PAI score had reduced to ≤2 in 87% of the patients, and the mean serum hsCRP levels had significantly reduced to 1.34 ± 0.52 mg L-1 (P < 0.001). Ten of the 15 patients had a reduction in their CVD risk status. CONCLUSIONS: This study suggests that root canal treatment can reduce serum hsCRP levels in systemically healthy individuals with apical periodontitis.

Comparing the anaesthetic efficacy of 1.8 mL and 3.6 mL of anaesthetic solution for inferior alveolar nerve blocks for teeth with irreversible pulpitis: a systematic review and meta-analysis with trial sequential analysis.

BACKGROUND: The scientific literature is contradictory in relation to selecting the appropriate volume of local anaesthetic solution for inferior alveolar nerve blocks (IANB) when attempting to anaesthetize mandibular teeth with irreversible pulpitis. OBJECTIVES: To compare the efficacy of 1.8 and 3.6 mL of the same anaesthetic solution for IANBs when treating mandibular teeth with irreversible pulpitis. METHODS: A literature search was performed in PubMed, Scopus and EBSCOhost databases until May 2020. Randomized clinical trials published in English, comparing 1.8 with 3.6 mL of the same anaesthetic solution for IANBs in permanent mandibular teeth with irreversible pulpitis, were included. The risk of bias of the included trials was appraised using the revised Cochrane risk of bias tool. A meta-analysis was performed using the random-effects model. The effect of random errors on the results of the meta-analysis was evaluated by trial sequential analysis and the quality of evidence was appraised using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. RESULTS: Four clinical trials involving 280 teeth from patients with ages ranging from 18 to 65 years were included. Among the four trials, three were categorized as having a 'low' risk of bias and one was categorized as having 'some concerns'. The primary meta-analysis revealed that 3.6 mL of anaesthetic solution when administered for IANBs was associated with significantly greater success rates compared with 1.8 mL (RR = 1.94; 95% CI, 1.07, 3.52; I2  = 77%). Similarly, the results of the sensitivity analysis (restricting trials only to those that used the Heft-Parker visual analogue pain scale) revealed that the use of 3.6 mL significantly increased the success of IANBs compared with 1.8 mL. The trial sequential analysis confirmed the evidence for the beneficial effect of 3.6 mL to achieve success for IANBs was 'conclusive'. The quality of evidence was graded as 'high'. CONCLUSION: Increasing the volume of anaesthetic solution from 1.8 to 3.6 mL improved the success rate for IANBs in mandibular molars with irreversible pulpitis. The quality of the evidence was 'high'. Future high-quality clinical trials are required with different types of anaesthetic solutions and other types of teeth.

Effect of two different concentrations of sodium hypochlorite on postoperative pain following single-visit root canal treatment: a triple-blind randomized clinical trial.

AIM: To compare the effects of two different concentrations of NaOCl solution on postoperative pain following single-visit root canal treatment in mandibular molars with irreversible pulpitis. METHODOLOGY: A total of 122 patients who had mandibular molars with irreversible pulpitis were treated. The patients were randomly divided into two groups according to the concentration of NaOCl used during root canal instrumentation - either 2.5% or 5.25%. RaCe rotary instruments were used for root canal preparation, and all root canals were filled in one visit. Postoperative pain was evaluated using the visual analogue scale. Data were analysed by independent t-test, chi-square and Mann-Whitney tests. RESULTS: Twelve patients were excluded for various reasons. Pain reported by 110 patients who were eligible to be included in the study was analysed. No significant differences were found in the age and gender of the patients between the two groups (P = 0.50, P = 0.51, respectively). The patients who had 5.25% NaOCl reported significantly lower postoperative pain compared to those who had 2.5% NaOCl during the first 72 h following treatment (P = 0.021); however, there was no significant difference in pain felt by the patients during the rest of the study period, that is 4-7 days following treatment (P = 0.185) when the four-level pain categorization method was used. When the two-level pain categorization method was used, the results revealed that patients who had 5.25% NaOCl reported significantly less pain for the first 3 days after treatment (P = 0.026). The number of analgesics taken by patients who had 2.5% NaOCl was significantly higher than that taken by patients who had 5.25% NaOCl (P = 0.001). CONCLUSION: 5.25% NaOCl was associated with significantly lower postoperative pain compared to 2.5% NaOCl during the first 72 h following one-visit root canal treatment of mandibular molars with irreversible pulpitis.

An analysis of the timing and materials associated with pulp disease following restorative dental treatment.

AIM: To assess whether the timing of pulp disease after tooth restoration was associated with type of restorative dental material used, extent of the restoration or tooth type. METHODOLOGY: A comprehensive search and analysis of data using the Titanium Oral Health Management software program at The Oral Health Centre of Western Australia were performed to correlate procedural codes for teeth that had restorations placed and subsequently developed pulp disease requiring endodontic treatment or extraction from 1st January 2009 to 31st December 2013. Manual analysis of paper and/or electronic patient record cards was also performed. Data collected included restoration type, restored tooth surfaces, tooth type and the dates of restoration and subsequent endodontic intervention or extraction. RESULTS: Of 330 teeth that met the inclusion criteria, 84 (26%) had composite resin restorations, 80 (24%) had amalgams, 119 (36%) had glass-ionomer cement (GICs), and 47 (14%) had crowns. The average time between restoration and further intervention was 330 days with a range from 3 to 1775 days (approximately 5 years). Teeth restored with crowns or five-surface restorations were significantly more likely to require earlier intervention than other restorations. Premolar and anterior teeth were also more likely to require earlier intervention. CONCLUSIONS: Teeth that developed pulp disease requiring further intervention that were restored with crowns and five-surface GIC developed the disease sooner than teeth that were restored with amalgam or composite. In teeth with five-surface restorations that developed pulp disease requiring further intervention, premolar and anterior teeth developed the pulp disease sooner than molars.

The extrusion of root canal cement containing paraformaldehyde into the inferior alveolar nerve canal resulting in infection and numbness.

AIM: To describe the impact of extruded paraformaldehyde-containing root canal cement into the inferior alveolar nerve canal following a delay in removal and the subsequent management of the case. SUMMARY: A 30-year-old man was referred for management of prolonged anaesthesia in the right mandibular region following root canal treatment. Panoramic and cone beam computed tomography findings revealed that overextruded root canal cement had penetrated into the inferior alveolar nerve canal beyond the distal root of the mandibular right second molar (tooth 47). The root canal cement contained paraformaldehyde. Initially, the patient refused surgical removal of the cement. However, after 3.5 months, the patient returned with an acute infection in the same region. After resolution of the acute abscess and root canal retreatment, surgical treatment was performed under general anaesthesia. Granulation tissue and necrotic bone were found associated with the cement.

A review of the effects of formaldehyde release from endodontic materials.

Formaldehyde is present in most living cells and the environment. In dentistry, patients may be exposed to formaldehyde through the use of several endodontic materials (e.g. AH 26) and during formocresol pulpotomies. This review outlines how the human body reacts to formaldehyde exposure, how recent data has relooked at the issue of carcinogenicity and leukaemia associated with formaldehyde, and whether it is possible to quantify the amount of formaldehyde produced by endodontic cements. The review analyses the way formaldehyde is produced from epoxy resins and addresses the question of whether the amount of formaldehyde from endodontic cements is large enough to override the body's ability to deal with its own endogenous levels of formaldehyde and should the amount of formaldehyde produced be a concern.

A study of the endodontic workforce in Australia in 2010.

AIMS: To investigate the current workforce situation for specialist Endodontists in Australia to help plan for the future of the specialty. METHODOLOGY: An online questionnaire was sent via email to all registered Endodontists that were identified from the Australian and New Zealand Academy of Endodontists database and the Australian Dental Association Directory. The questionnaire comprised questions on demographic characteristics, practice type, teaching and research activities, busyness and expected retirement time. All results were transferred to a statistical software program (SPSS v.19) for analysis. RESULTS: The response rate was 50%. The majority of respondents (84%) were male. The most common (64.5%) type of practice was single location private practice. The majority (93%) of Endodontists are located in state capital cities. Many respondents (61%) did some teaching. A minority of respondents (16%) were currently involved in research. The next available nonemergency appointment was more than 1 week away for 84% of respondents. More than half the respondents (52%) do not have allocated time for emergency patients. Only 18% of respondents plan to retire in the next 5 years and another 15% within 5-10 years. Although 58% of practice owners indicated that they have sufficient space and facilities to employ another Endodontist, only 33% would consider to employ or have an associate join their practice. CONCLUSION: Most Endodontists in Australia are male private practitioners who work in a single state capital city location. Many teach but few carry out research. They are fully booked with routine patients and have no spare scheduled appointments for emergencies; these have to be seen at the end of the day, or between scheduled patients. There will be a steady rate of retirement in the future and only just enough newly qualified Endodontists are being trained to maintain the specialty workforce at current levels.

Allergic reaction to the tetracycline component of Ledermix paste: a case report.

AIM: Allergy to materials used during root canal treatment is well recognized in the endodontic literature. However, allergy to Ledermix paste, a compound containing triamcinolone (a corticosteroid) and demeclocycline (a tetracycline antibiotic), has not been reported apart from one very recent case in a Letter to the Editor of a journal. The aim of this report is to describe a proven allergic reaction to tetracycline following the use of Ledermix paste as a root canal medicament. SUMMARY: A 33-year-old female patient undergoing root canal retreatment of her right mandibular second premolar tooth experienced symptoms of type 1 allergy following the placement of an intracanal medicament containing a mixture of Ledermix paste and calcium hydroxide [Ca(OH)2 ]. Signs of the type 1 allergy included urticaria, pruritus all over the body, general malaise and fever. These all subsided after removing and flushing out the Ledermix paste-Ca(OH)2 mixture and redressing the root canal with Ca(OH)2 alone. Allergic scratch tests were performed, and these confirmed that the patient was allergic to tetracycline, one of the components of Ledermix paste.

Efficacy of supplementary buccal infiltrations and intraligamentary injections to inferior alveolar nerve blocks in mandibular first molars with asymptomatic irreversible pulpitis: a randomized controlled trial.

AIM: This randomized double-blinded controlled trial was performed to compare the efficacy of inferior alveolar nerve block (IANB) injection for mandibular first molar teeth with irreversible pulpitis with or without supplementary buccal infiltration and intraligamentary injection. METHODOLOGY: Eighty-two patients with asymptomatic irreversible pulpitis received either a combination of intraligamentary injection + buccal infiltration+ IANB or with traditional IANB injection in mandibular first molar teeth with irreversible pulpitis. Each patient recorded their pain score on a Heft-Parker visual analogue scale before commencing treatment, in response to a cold test 15 min after the designated anaesthetic injection, during access cavity preparation and during root canal instrumentation. No or mild pain at any stage was considered a success. Data were analysed by chi-square test. RESULTS: At the final stage of treatment, 69 of the 82 patients were eligible to be included in the study. No significant difference was found between age (P = 0.569) and gender (P = 0.570) amongst the patients in the two groups. The success rate of anaesthesia in the IANB and the combination groups were 22% and 58%, respectively. The success rate of anaesthesia in the combination group was significantly higher than the traditional IANB injection (P = 0.003). CONCLUSION: A combination of anaesthetic techniques can improve the success rate of anaesthesia for mandibular first molar teeth with irreversible pulpitis.

Randomized control trial comparing calcium hydroxide and mineral trioxide aggregate for partial pulpotomies in cariously exposed pulps of permanent molars.

AIM: To compare the treatment outcomes when calcium hydroxide and mineral trioxide aggregate are used for partial pulpotomy in cariously exposed young permanent molars in a randomized control trial. METHODOLOGY: Eighty-four teeth in 80 volunteers (aged 7-10 years) with reversible pulpitis and carious pulp exposures were randomly divided into two groups. Exposed pulps were severed using high-speed round burs until fresh pulp was seen. Cavities were irrigated with 2.5% sodium hypochlorite, and the pulp exposures were photographed and measured. Dycal or ProRoot MTA was placed on the pulp. Vitremer was placed over the material until the remaining cavity was 2 mm deep; amalgam was then placed. Teeth were evaluated for clinical symptoms and radiographic periapical changes after 24 h, 3 months, 6 months, 1 year and 2 years. Mean survival times and incidence of extraction were calculated using exact binomial confidence intervals. RESULTS: The median survival time for both ProRoot MTA and Dycal groups was 24 months. Three teeth had unfavourable outcomes with the incidence rate of 0.20/100 tooth-months with ProRoot MTA (95% CI: 0.02-0.71) and 0.11/100 tooth-months with Dycal (95% CI: 0.001-0.60). The incidence of unfavourable outcomes was 0.05/100 (95% CI: 0.001-0.30) and 2.38/100 (95% CI: 0.29-8.34) tooth-months in teeth with small (<5 mm(2) ) and large (>5 mm(2) ) pulp exposure areas, respectively. CONCLUSIONS: Partial pulpotomy in teeth of young patients with reversible pulpitis, either using ProRoot MTA or Dycal, resulted in favourable treatment outcomes for up to 2 years. The incidence of unfavourable outcomes tended to be higher in teeth with pulp exposure areas larger than 5 mm(2) .

The Effect of Water Coolant and Bur Type on Pulp Temperature When Removing Tooth Structure and Restorative Dental Materials.

OBJECTIVE: The aim was to compare intrapulp temperature (IPT) changes when flat-fissure diamond burs and pear-shaped tungsten carbide burs were used to cut tooth structure, amalgam, and composite resin with and without water coolant. METHODS: Thermocouples were inserted into the pulp chamber of extracted intact mandibular molars. The thermocouples were connected to an electronic thermometer that detects temperature every second to an accuracy of 0.1°C. IPT changes were recorded while using a high-speed handpiece during MOD cavity preparations (n=40), composite resin removal (n=40), and amalgam removal (n=40). A two-way ANOVA was used for each procedure to test for the effect of bur (pear-shaped tungsten carbide vs flat-fissured diamond) and water coolant (on vs off), with significant main effects (α=0.05) further analyzed using Tukey's multiple comparison test. RESULTS: During MOD cavity preparation, water coolant reduced changes in IPT (0.03±0.27°C) compared to no water coolant (1.27±0.29°C) when tungsten carbide burs were used (p<0.05) but not when diamond burs were used. During composite resin removal, tungsten carbide burs had less changes in IPT (0.55±0.18°C) compared to diamond burs (1.66±0.50°C) with no water coolant (p<0.05). Water coolant also reduced changes in IPT (0.09±0.14°C) compared to no water coolant (1.66±0.50°C) when diamond burs were used (p<0.01). Water coolant did not significantly affect IPT when tungsten carbide burs were used. During amalgam removal, tungsten carbide burs had lower changes in IPT (0.56±0.15°C) compared to diamond burs (1.88±0.43°C) with no water coolant (p<0.05). Water coolant also significantly reduced changes in IPT (0.71±0.2°C) compared to no water coolant (1.88±0.43°C) when diamond burs were used (p<0.05) but not when tungsten carbide burs were used. CONCLUSIONS: Water coolant reduced IPT changes when drilling tooth structure with tungsten carbide burs, but not when removing amalgam or composite. Conversely, water coolant reduced IPT changes when drilling with flat fissure diamond burs to remove amalgam and composite, but not when removing tooth structure. When amalgam and composite were removed without water coolant, the tungsten carbide burs resulted in lower IPT changes than when flat fissure diamond burs were used in the same way.

Relationship of selection criteria to subsequent academic performance in an Australian undergraduate dental school.

In 1998, in addition to previous academic achievement, an aptitude test (UMAT) and a structured interview were introduced into selection for the Bachelor of Dental Science (BDSc), the undergraduate dental course at the University of Western Australia. The aim of this study was to determine the relationship between the combination of school-leaver dental students' entry scores, some demographic characteristics and subsequent student performance in the undergraduate course. Three hundred and ninety-eight school-leavers who enrolled in the BDSc from 1999 through 2011 were studied. Regression models were constructed comprising entry scores, gender and age as predictors in relation to subsequent academic performance. The main outcome measure was the weighted average mark (WAM) for each of five academic year levels as well as results in specific units, defined as either 'knowledge' based or 'clinically' based. Of the variables studied, previous academic performance and female gender had the strongest relationship with yearly WAM for Years 1 through 4 and for both 'knowledge' based and 'clinically' based units. The interview score showed a strong relationship in the major clinical years and in a range of 'clinically' based units. UMAT scores were less consistent in relationship to WAM. These results support assessment through a highly structured interview together with prior academic achievement as an evidence-based approach to selection of students for this undergraduate dental course.

First reflections: third-year dentistry students' introduction to reflective practice.

INTRODUCTION: To develop both professionally and personally, health professionals need to build essential skills in reflective practice. Educators generally agree that these skills should be developed as part of curricula for health professional students. The aims were to introduce reflective practice to third-year dentistry students and to evaluate the students' self-perceived reflective skills before and after their reflective activities. MATERIALS AND METHODS: Using a written questionnaire, third-year dentistry students' perceptions of reflective practice were gathered before and after their first clinic placement. Students also completed two reflective writing pieces about their clinical placements. RESULTS: The students' reflective writing pieces were allocated into one of the three categories: non-reflector, reflector and critical reflector. Content analysis of students' perceptions of reflective practice revealed nine themes. Eight main themes emerged from students' suggestions for improving their reflective abilities. DISCUSSION AND CONCLUSION: Issues around the assessment of reflective writing are discussed, and students' suggestions for improving their reflective abilities are presented.

Indications for root canal treatment following traumatic dental injuries to permanent teeth.

The dental pulp may respond favourably or unfavourably to traumatic dental injuries. The most serious unfavourable responses are pulp necrosis and infection of the root canal system. These cause apical periodontitis and/or external inflammatory resorption of the tooth. The following injuries require root canal treatment as part of their emergency management-(A) complicated crown fractures (but some may be suitable for conservative pulp treatments, such as pulp capping, partial pulpotomy or pulpotomy), (B) complicated crown-root fractures, (C) supra-crestal coronal third root fractures and (D) injuries where pulp necrosis is predictable or highly likely to occur AND where there has been damage to the root surface and/or periodontal ligament with the aim of preventing external inflammatory resorption. This latter group of injuries are avulsion, intrusion, lateral luxation with a crown fracture, extrusion with a crown fracture (all in fully developed teeth) plus avulsion with a crown fracture and intrusion with a crown fracture (both in incompletely developed teeth). All other injuries should not have root canal treatment commenced as part of the emergency management, but they must be reviewed regularly to monitor the pulp for any adverse changes to its status, particularly pulp necrosis and infection of the root canal system.

Discolouration potential of endodontic procedures and materials: a review.

Advances in endodontic materials and techniques are at the forefront of endodontic research. Despite continuous improvements, tooth discolouration, especially in anterior teeth, is considered an undesirable consequence following endodontic treatment as it creates a range of aesthetic problems. This article aims to discuss the intrinsic and internalized tooth discolouration caused by endodontic procedures, and to address the discolouration potential of materials used during root canal treatment, including root canal irrigants, intra-canal medicaments, endodontic and post-endodontic filling materials. In addition, the discolouration patterns caused by combined endodontic and nonendodontic aetiological factors are discussed. The recommended guidelines that should be followed by dental practitioners to prevent and manage tooth discolouration are also outlined.

Effects of three oral analgesics on postoperative pain following root canal preparation: a controlled clinical trial.

AIM: To compare the effects of single doses of three oral medications on postoperative pain following instrumentation of root canals in teeth with irreversible pulpitis. METHODOLOGY: In this double-blind clinical trial, 100 patients who had anterior or premolar teeth with irreversible pulpitis without any signs and symptoms of acute or chronic apical periodontitis and moderate to severe pain were divided by balanced block random allocation into four groups of 25 each, a control group receiving a placebo medication, and three experimental groups receiving a single dose of either Tramadol (100 mg), Novafen (325 mg of paracetamol, 200 mg ibuprofen and 40 mg caffeine anhydrous) or Naproxen (500 mg) immediately after the first appointment where the pulp was removed, and the canals were fully prepared. The intensity of pain was scored based on 10-point VAS before and after treatment for up to 24 h postoperatively. Data were submitted to repeated analysis of variance. RESULTS: At the 6, 12 and 24 h postoperative intervals after drug administration, the intensity of pain was significantly lower in the experimental groups than in the placebo group (P < 0.01). Tramadol was significantly less effective (P < 0.05) than Naproxen, and Novafen that were similar to each other (P > 0.05). CONCLUSION: A single oral dose of Naproxen, Novafen and Tramadol taken immediately after treatment reduced postoperative pain following pulpectomy and root canal preparation of teeth with irreversible pulpitis.

Review of pulp sensibility tests. Part II: electric pulp tests and test cavities.

The electric pulp test (EPT) is one type of pulp sensibility test that can be used as an aid in the diagnosis of the status of the dental pulp. However, like thermal pulp sensibility tests, it does not provide any direct information about the vitality (blood supply) of the pulp or whether the pulp is necrotic. 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 articles published between November 1964 and January 2009 in all languages. The EPT is technique sensitive, and false responses may occur. Various factors can affect the test results, and therefore it is important that dental practitioners understand the nature of these tests and how to interpret them. Test cavities have been suggested as another method for assessing the pulp status; however, the use of this technique needs careful consideration because of its invasive and irreversible nature. In addition, it is unlikely to be useful in apprehensive patients and should not be required because it provides no further information beyond what thermal and electric pulp sensibility tests provide - that is, whether the pulp is able to respond to a stimulus. A review of the literature and a discussion of the important points regarding these two tests are presented.

Review of pulp sensibility tests. Part I: general information and thermal tests.

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.

Root canal morphology of hypomineralised first permanent molars using micro-CT.

AIM: To investigate the root canal morphology of hypomineralised first permanent molars (FPMs) using micro-CT (µCT). METHODOLOGY: Twenty-four hypomineralised FPMs and five clinically sound FPMs were scanned using µCT and assessed using the following parameters: (i) root canal configuration, (ii) connecting canal frequency, (iii) enamel, dentin, and pulp volumes, (iv) cusp tip to pulp horn distance, root canal length, root canal width, and dentin thickness, and (v) the influence of the root canal system landmarks on access cavity outline forms and canal curvature. A two-way repeated-measures analysis of variance was employed with the statistical significance set at p < 0.05. RESULTS: The frequency of accessory and connecting canals was higher in hypomineralised FPMs. Mesio-buccal cusp horn was found to be the closest to its corresponding cusp tip in both groups. There was no significant difference between the root lengths, dentine widths, and pulp space measurements of hypomineralised FPMs compared to clinically sound FPMs. The best angulation to access FPMs was straight-line radicular, along the pulp horn. CONCLUSIONS: This study illustrates some variations in the root canal morphology in hypomineralised FPMs compared to clinically sound FPMs. Future studies should focus on assessing these parameters in larger samples.