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.

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.

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.

Radiation shielding in dentistry: an update

The purpose of this article was to review the literature and provide guidelines on the use of radiation protection for patients in the dental setting. There are limited published data on the effects of low radiation doses such as those used in dental radiology. Most of the evidence is subject to bias, with risk models extrapolated from higher dose models such as studies of the Hiroshima bomb survivors. However, the lack of evidence does not denote the absence of risk, as there is no established 'safe' level of radiation exposure. All imaging utilizing ionizing radiation carries a risk for the patient. Hence the patient benefits of imaging must outweigh the potential risk. All diagnostic imaging should adhere to three basic principles, these being justification, optimization and application of dose limits. This article discusses dose reduction techniques and shielding of sensitive organs, particularly the thyroid, during procedures such as intraoral imaging, orthopantomograms and imaging of the pregnant patient.

Efficacy of reciprocating and rotary systems for removing root filling material: a micro-computed tomography study

This study aimed to use micro-computed tomography (micro-CT) imaging to evaluate the efficacy of the reciprocating and rotary systems for the removal of root filling materials in comparison with hand files. Thirty maxillary incisor teeth were prepared with ProTaper Universal (PTU) system, filled using cold lateral condensation and randomly divided into three groups of ten teeth each. The root fillings were removed with WaveOne Reciprocating and ProTaper Universal Re-treatment (PTU-R) systems and hand files. Micro-CT was used to scan the specimens before and after each treatment step. Percentage of volume of residual root filling was measured. The operating time was recorded. PTU-R instruments yielded better results for removing filling material, even though there was no statistically significant difference between PTU-R and WaveOne groups. Reciprocating and rotary systems showed similar performances in terms of efficacy and operating time for root filling removal.

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.

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.

Parental knowledge and attitudes towards dental radiography for children

BACKGROUND

Radiographs are an essential part of most clinical dental examinations and diagnoses. The aim of the study was to assess the knowledge and attitudes of parents towards dental radiographs for their children.

METHODS

A 21-item questionnaire, covering parental level of radiation knowledge and socio-demographics was applied. Sliding scales were used to assess attitude towards dental radiographs.

RESULTS

There were 1467 questionnaires distributed between five primary schools in the Perth (Western Australia) metropolitan area, with 309 surveys (21%) returned for collection. Most parents displayed a low level of knowledge, but had a positive attitude towards dental radiographs. Parents with children who have previously had dental radiographs perceived dental radiographs as 'good', 'useful' and 'pleasant'. A higher level of education and parents with children who have previously had radiographs were significantly associated with a higher level of knowledge about dental radiography. Parents who had higher scores on questions assessing radiation knowledge were more likely to perceive dental radiographs as 'safe' and 'beneficial'.

CONCLUSIONS

Most parents have a positive attitude towards dental radiographs on their children. However, the majority of parents lack knowledge regarding dental radiography, especially regarding the risks involved.

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.

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.

Comparison of the microhardness and morphology of five different retrograde filling materials in aqueous and dry conditions

The purpose of the present study was to compare the effect of dry and aqueous conditions on the surface morphology and surface hardness of five materials 24 h after being used as fillings without initial setting time in dry condition. The five materials were ProRoot mineral trioxide aggregate (MTA), super EBA, intermediate restorative materials (IRM), zinc oxide eugenol (ZOE), and amalgam. To evaluate microhardness, the five materials were submitted to the Vickers microhardness (VHN) test. We used a scanning electron microscope (Steroscan 440, Leica Cambridge, England) to observe the microstructural morphology of the five different materials. The VHN of MTA soaked in water showed five times lower than that of MTA soaked in dry condition. On the other hand, super EBA was less influenced by the medium of storage compared with the other materials. Scanning electron microscope (SEM) images showed the similar results with microhardness tests. The surface of MTA soaked in water appeared to be unstable compared with that of dry condition while super EBA showed similarly smooth surface in both conditions (aqueous and dry). In conclusion, the physical property of MTA is reduced after storage in water; however, super EBA is less influenced by aqueous condition.

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.

In vitro study of the inactivation by dentine of some endodontic medicaments and their bases

BACKGROUND

The aim of this study was to investigate the antimicrobial effect of endodontic medicaments and their bases in the presence of dentine powder.

METHODS

The medicaments tested were Ledermix paste, Pulpdent paste, a 50:50 combination of the Pulpdent:Ledermix and their bases. The test organism was Enterococcus faecalis ATCC 29212. The presence or absence of dentine was examined as well as the effect of autoclaving dentine. Serial dilutions of samples at 1 hour, 1 day and 3 days were used for colony counting. The effects of dentine powder on pH for saturated Ca(OH)2 solution and Pulpdent paste at 1 hour and 24 hours were also measured.

RESULTS

Pulpdent and the 50:50 combination of Pulpdent:Ledermix completely inhibited the growth of E. faecalis from 1 hour onwards, and these results were not affected by the presence/absence of dentine powder, pre-incubation period, timing of autoclaving, or exposure time. Saturated solutions of Ca(OH)2 are prone to inactivation by dentine powder unlike Pulpdent paste. Ledermix paste took 3 days to exert a significant effect on the growth of E. faecalis.

CONCLUSIONS

In this laboratory study, both Pulpdent and the 50:50 mixture of Pulpdent with Ledermix were effective medicaments against E. faecalis in the presence of dentine powder.

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.

Strategies for the endodontic management of concurrent endodontic and periodontal diseases

Endodontic and periodontal diseases can provide many diagnostic and management challenges to clinicians, particularly when they occur concurrently. As with all diseases, a thorough history combined with comprehensive clinical and radiographic examinations are all required so an accurate diagnosis can be made. This is essential since the diagnosis will determine the type and sequence of treatment required. This paper reviews the relevant literature and proposes a new classification for concurrent endodontic and periodontal diseases. This classification is a simple one that will help clinicians to formulate management plans for when these diseases occur concurrently. The key aspects are to determine whether both types of diseases are present, rather than just having manifestations of one disease in the alternate tissue. Once it is established that both diseases are present and that they are as a result of infections of each tissue, then the clinician must determine whether the two diseases communicate via the periodontal pocket so that appropriate management can be provided using the guidelines outlined. In general, if the root canal system is infected, endodontic treatment should be commenced prior to any periodontal therapy in order to remove the intracanal infection before any cementum is removed. This avoids several complications and provides a more favourable environment for periodontal repair. The endodontic treatment can be completed before periodontal treatment is provided when there is no communication between the disease processes. However, when there is communication between the two disease processes, then the root canals should be medicated until the periodontal treatment has been completed and the overall prognosis of the tooth has been reassessed as being favourable. The use of non-toxic intracanal therapeutic medicaments is essential to destroy bacteria and to help encourage tissue repair.

An overview of the dental pulp: its functions and responses to injury

The dental pulp is a unique tissue and its importance in the long-term prognosis of the tooth is often ignored by clinicians. It is unique in that it resides in a rigid chamber which provides strong mechanical support and protection from the microbial rich oral environment. If this rigid shell loses its structural integrity, the pulp is under the threat of the adverse stimuli from the mouth, such as caries, cracks, fractures and open restoration margins, all of which provide pathways for micro-organisms and their toxins to enter the pulp. The pulp initially responds to irritation by becoming inflamed and, if left untreated, this will progress to pulp necrosis and infection. The inflammation will also spread to the surrounding alveolar bone and cause periapical pathosis. The magnitude of pulp-related problems should not be underestimated since their most serious consequence is oral sepsis, which can be life threatening, and hence correct diagnosis and management are essential. Clinicians must have a thorough understanding of the physiological and pathological features of the dental pulp as well as the biological consequences of treatment interventions.

A clinical classification of the status of the pulp and the root canal system

Many different classification systems have been advocated for pulp diseases. However, most of them are based on histopathological findings rather than clinical findings which leads to confusion since there is little correlation between them. Most classifications mix clinical and histological terms resulting in misleading terminology and diagnoses. This in turn leads to further confusion and uncertainty in clinical practice when a rational treatment plan needs to be established in order to manage a specific pathological entity. A simple, yet practical classification of pulp diseases which uses terminology related to clinical findings is proposed. This classification will help clinicians understand the progressive nature of the pulp disease processes and direct them to the most appropriate and conservative treatment strategy for each condition. With a comprehensive knowledge of the pathophysiology of pain and inflammation in the pulp tissues, clinicians may accomplish this task with confidence.

Interim and temporary restoration of teeth during endodontic treatment

One of the main aims of endodontic treatment is to eliminate micro-organisms from within the root canal system. A further aim is to prevent the ingress of any further bacteria during and after treatment. These aims are usually achieved by various means and stages throughout the treatment process. Endodontic treatment is usually performed on teeth that have lost the integrity of the external coronal tooth structure which has allowed bacteria to enter the tooth and ultimately reach the pulp space. Further opening of the tooth occurs when an endodontic access cavity is made to allow treatment to be performed. Hence, there will always be a need for interim and temporary restoration of teeth undergoing endodontic treatment. Many different materials and techniques have been proposed, and these proposals have been based on many research reports. The purposes of this article are to review the literature regarding the use of interim and temporary restorations, and to provide recommendations regarding such restorations for clinicians to follow when providing endodontic treatment.

The use of calcium hydroxide, antibiotics and biocides as antimicrobial medicaments in endodontics

Bacteria have been implicated in the pathogenesis and progression of pulp and periapical diseases. The primary aim of endodontic treatment is to remove as many bacteria as possible from the root canal system and then to create an environment in which any remaining organisms cannot survive. This can only be achieved through the use of a combination of aseptic treatment techniques, chemomechanical preparation of the root canal, antimicrobial irrigating solutions and intracanal medicaments. The choice of which intracanal medicament to use is dependent on having an accurate diagnosis of the condition being treated, as well as a thorough knowledge of the type of organisms likely to be involved and their mechanisms of growth and survival. Since the disease is likely to have been caused by the presence of bacteria within the root canal, the use of an antimicrobial agent is essential. Many medicaments have been used in an attempt to achieve the above aims but no single preparation has been found to be completely predictable or effective. Commonly used medicaments include calcium hydroxide, antibiotics, non-phenolic biocides, phenolic biocides and iodine compounds. Each has advantages and disadvantages, and further research is required to determine which is best suited for root canal infections.

Clinical, radiographic and histological analysis of the effects of mineral trioxide aggregate used in direct pulp capping and pulpotomies of primary teeth

BACKGROUND

Primary teeth pulp exposures have traditionally been treated with formocresol or ferric sulphate pulpotomies or calcium hydroxide pulp capping. The aim of this study was to observe the tissue response when mineral trioxide aggregate (MTA) was used.

METHODS

Ten primary teeth had direct pulp caps and 11 had a pulpotomy with MTA. The teeth were restored and then clinically reviewed monthly for five months and before extraction. Radiographs were taken prior to treatment, after one month and prior to extraction. After extraction, the teeth were examined histologically and the responses to treatment were assessed.

RESULTS

One pulpotomy and two pulp capping cases had postoperative pain and signs of pulp degeneration. Radiographs showed no root resorption, no periodontal pockets and no furcation radiolucencies. No cases had draining sinuses or increased mobility. Most pulps responded favourably from a clinical perspective although a variety of responses were noted histologically--normal odontoblasts, irregular odontoblasts, intra-pulpal calcifications, dentinal bridges, cementum formation, internal resorption, inflammatory infiltrate and pulp necrosis.

CONCLUSIONS

The responses of pulps in primary teeth to MTA pulpotomies and pulp caps were favourable from clinical and radiographic perspectives although a variety of histological responses were noted. MTA may be a favourable material for pulp capping and pulpotomies in primary teeth.

Drugs for pain management in dentistry

Pain is one of the most common reasons patients seek dental treatment. It may be due to many different diseases/conditions or it may occur after treatment. Dentists must be able to diagnose the source of pain and have strategies for its management. The '3-D's' principle--diagnosis, dental treatment and drugs--should be used to manage pain. The first, and most important, step is to diagnose the condition causing the pain and identify what caused that condition. Appropriate dental treatment should then be undertaken to remove the cause of the condition as this usually provides rapid resolution of the symptoms. Drugs should only be used as an adjunct to the dental treatment. Most painful problems that require analgesics will be due to inflammation. Pain management drugs include non-narcotic analgesics (e.g., non-steroidal anti-inflammatory drugs, paracetamol, etc) or opioids (i.e., narcotics). Non-steroidal anti-inflammatory drugs (NSAIDs) provide excellent pain relief due to their anti-inflammatory and analgesic action. The most common NSAIDs are aspirin and ibuprofen. Paracetamol gives very effective analgesia but has little anti-inflammatory action. The opioids are powerful analgesics but have significant side effects and therefore they should be reserved for severe pain only. The most commonly-used opioid is codeine, usually in combination with paracetamol. Corticosteroids can also be used for managing inflammation but their use in dentistry is limited to a few very specific situations.

Prevalence of apical periodontitis and the quality of endodontic treatment in an adult Belarusian population

AIM

To estimate the prevalence of teeth with apical periodontitis (AP) and technically failed root fillings in an adult Belarusian population.

METHODOLOGY

Panoramic radiographs of all 1423 patients over 15 years of age not seeking emergency dental care, and attending the Dental School of the Belarusian Medical University for the first time during the period from 1 January to 31 December 2001 were examined. The quality of root fillings was scored according to criteria of length proposed by De Moor et al. [International Endodontic Journal 33 (2000) 113] and the periapical status of all teeth (except third molars) was categorized on the basis of presence or absence of radiographic signs of AP. The data were analysed using the chi-square test and odds ratio.

RESULTS

Radiographs indicated that 8632 teeth (22% in the maxilla; 21% in the mandible) were missing leaving a total of 31,212 teeth to be assessed. Twenty per cent of the teeth had some filling material in the root canal(s). AP was found in 1141 subjects (80%) and 12% of the teeth. AP was more frequently associated with molar teeth (23%) than premolar (14%), canine (4%) and incisor teeth (6%). AP was diagnosed in 45% of root filled teeth, the remaining cases with AP had not been root filled. Statistical analysis showed that the probability of radiological detection of AP in root filled teeth was 25-fold higher than when the root canals had not been filled (chi2 = 8636.04, P < or = 0.001, odds ratio with 95% confidence intervals: 23.01 < 25.17 < 27.45). Periapical radiolucencies with adequately filled root canals occurred significantly less often than with teeth in which the root canal was filled more than 2 mm from radiographic apex or when filling material was extruded through the apex.

CONCLUSION

The prevalence of AP in all age groups in Belarus was higher than in other populations. The probability of AP increased significantly after root canal treatment and was closely correlated with the quality of the root filling.

Assessing restored teeth with pulp and periapical diseases for the presence of cracks, caries and marginal breakdown

BACKGROUND

To determine whether clinical examinations and periapical radiographs provide sufficient information to assess the cause of pulp and periapical diseases, the status of teeth when restored and their further treatment needs. Other aims were to determine whether restorations should be removed prior to commencing endodontic treatment, and whether the type and longevity of restorations were related to the presence of disease.

METHODS

Information was collected regarding 245 restored teeth from 220 consecutive patients referred for endodontic treatment. Teeth were examined before and after the restorations were removed and the findings were compared.

RESULTS

Pre-operative examination revealed 47 (19.2 per cent) teeth had caries, 57 (23.3 per cent) had cracks and 96 (39.2 per cent) had marginal breakdown. After restoration removal, the figures were 211 (86.1 per cent), 147 (60 per cent), and 244 (99.6 per cent) respectively. Almost all teeth (93 per cent) had more than one of these factors and periapical radiographs were unreliable indicators of their presence. There was only a 56.1 per cent chance (with 95 per cent Confidence Interval) of finding caries, cracks or marginal breakdown prior to restoration removal. Composite resins were more often associated with early onset and rapid progression of pulp diseases.

CONCLUSIONS

All restorations should be removed prior to endodontic treatment in order to remove the common factors that may have caused the pulp and periapical disease, and to assess the tooth's prognosis and future treatment needs.

Effect of immediate intracanal placement of Ledermix Paste(R) on healing of replanted dog teeth after extended dry times

Ledermix Paste is a paste containing triamcinolone and demeclocycline with demonstrated anti-inflammatory activity that may slow down resorptive processes after severe traumatic injuries to the dentition. A total of 29 premolar roots of six mongrel dogs were extracted and instrumented with rotary nickel titanium files. Fifteen of these roots were then filled with a calcium hydroxide (Ca(OH)2) slurry and 14 roots were filled with Ledermix Paste paste. All accesses were sealed with glass ionomer and the roots replanted after an extraoral dry time of 60 min. After 4 months, the dogs were killed and the roots prepared for histological evaluation. Five-micrometer thick cross-sections of the root and surrounding tissue taken every 90 micro m were evaluated for healing. In addition, residual root mass was also measured to determine the extent of root structure loss for each treatment method. The Ledermix Paste-treated roots had statistically significantly more healing and less resorption than the roots treated with Ca(OH)2. Root filling with Ledermix Paste also resulted in significantly less loss in root mass due to resorption compared to those roots filled with Ca(OH)2. Immediate intracanal placement of Ledermix Paste at the emergency visit after an avulsion injury appears to decrease resorption and increase favorable healing.

Measurement of strain on tooth roots during post removal with the Eggler post remover

AIM

The aim was to measure root surface strains in teeth when removing cast post/cores with the Eggler post remover.

METHODOLOGY

Two groups of 10 teeth each were tested: group 1 had 1 mm thickness of dentine coronally, and group 2 had 2 mm thickness of dentine. After root filling, 10 mm long cast post/cores were constructed and cemented with zinc phosphate cement, and strain gauges were applied to the roots. The post/cores were removed with the Eggler post remover whilst strain measurements were being recorded. Posts were removed twice: initially along the long axis of the tooth and then at a 10 degrees angle to the long axis. Comparisons between groups 1 and 2 were analysed statistically with the Mann-Whitney U-test whilst strains within each group were analysed with the Wilcoxon Signed Rank test at the 95% level of confidence.

RESULTS

There was no significant difference in the strains measured between groups 1 and 2, and no significant difference within each group when removing posts along the long axis of the tooth and at a 10 degrees angle. Three teeth in group 1 and one tooth in group 2 fractured when removing posts at the 10 degrees angle. Three fractures were small slivers of dentine at the point where the Eggler's repeller arms contacted the tooth mesially and distally, whilst one tooth (from group 1) fractured obliquely.

CONCLUSIONS

Post removal with the Eggler device is a relatively safe procedure but care must be taken when there is a possibility of pulling the post out in a nonaxial direction or when less than 1 mm of dentine surrounds the apical end of the post.

Incidence of root fractures and methods used for post removal

AIM

This study was undertaken to determine the incidence of root fractures during post removal, as well as the methods used and the success rates achieved with various post removal devices and techniques.

METHODOLOGY

Patient records from a specialist endodontic practice were examined. A total of 1600 teeth from which posts were removed were identified. These teeth had no preoperative signs or symptoms to suggest root fractures. The incidence of root fractures was determined and a subset of 234 patient records were examined in detail to determine the methods used to remove different types of posts.

RESULTS

Only one tooth fractured during post removal (0.06%) and all posts were successfully removed, typically in about 3 min. Most cast posts were removed with an Eggler post remover but some dislodged when the crown was removed; ultrasonics was used occasionally. Most parallel-sided posts were removed with ultrasonics and threaded posts were unscrewed. The Masserann kit and ultrasonics were combined to remove fractured cast posts and some parallel-sided posts.

CONCLUSIONS

This study indicates that, with good case selection, post removal is a predictable procedure. If appropriate techniques and devices are used for the particular type of post being removed, then root fracture is a rare occurrence.

Correlation between clinical success and apical dye penetration

AIM

This study was undertaken to examine whether a correlation exists between apical dye penetration and the clinical performance of root fillings.

METHODOLOGY

Apical dye penetration into 116 roots of human teeth that had been root-filled at least 6 months prior to extraction was tested in vitro using a vacuum technique and by measuring the length of dye penetration. Endodontic treatment was classified as clinically successful or unsuccessful and results for these groups were compared using analysis of variance and the Student's t-test. Positive and negative controls were used to test the experimental system.

RESULTS

All controls performed as expected. Dye penetrated significantly further in unsuccessful cases although the raw data suggested little difference. Overall, dye penetrated 99.5% of the specimens, indicating that the presence of dye in the canal is a poor indicator of whether the technique or material will succeed. However, the extent of dye penetration may be related to the clinical outcome.

CONCLUSIONS

Clinically placed root canal fillings do not provide an apical seal that prevents fluid penetration. The outcome of treatment cannot be predicted from the results of apical dye leakage studies.

Blood flow changes in human dental pulps when capsaicin is applied to the adjacent gingival mucosa

OBJECTIVE

The purpose of this study was to determine whether changes occur in pulpal blood flow when capsaicin is applied to the adjacent gingival or alveolar mucosa in human beings.

STUDY DESIGN

Laser Doppler flowmetry was used to measure changes in pulpal blood flow (PBF) after applying capsaicin to adjacent gingival mucosa in 20 human volunteers. The procedure was repeated on 10 subjects after administration of an ipsilateral inferior alveolar nerve block and on the other 10 subjects after application of topical anesthetic to their adjacent gingival and alveolar mucosa.

RESULTS

PBF increased in 16 subjects and did not change in 4 subjects after capsaicin application. Ipsilateral inferior alveolar nerve block did not alter this effect. Pretreatment with topical lidocaine resulted in no change or decreased PBF in 8 subjects and increased PBF in 2 subjects.

CONCLUSION

Changes occur in the PBF of the mandibular canine teeth of some humans when capsaicin is applied to the adjacent gingival or alveolar mucosa.

Apical inflammatory root resorption: a correlative radiographic and histological assessment

AIM

To assess the reliability of routine single radiographs in the diagnosis of inflammatory apical root resorption by correlating the radiographic and histological findings.

METHODOLOGY

The material comprised serial and step serial sections of plastic-embedded root-apices with attached apical periodontitis lesions that were prepared for a previous study and the diagnostic radiographs. The histological sections of 114 specimens were analysed by light microscopy and categorized into three groups: (i) those without any resorption (0); (ii) those with moderate resorption (+); and (iii) those with severe resorption (+ +). The radiographs were examined by a separate examiner and graded with a similar categorization of no resorption (0); moderate (+); and severe (+ +) apical resorption.

RESULTS

Radiographically, 19% of the teeth were diagnosed as having apical inflammatory root resorption, whereas histologically, 81% of the teeth revealed apical inflammatory root resorption. A correlative radiographic and histological assessment (n = 104) revealed a coincidence of diagnosis in 7% of the specimens and noncoincidence of diagnosis in 76% of the specimens.

CONCLUSIONS

The results indicate that routine single radiographs are not sufficiently accurate or sensitive to consistently diagnose apical root resorptive defects developing as a consequence of apical periodontitis.

The periapical space--a dynamic interface

The ultimate aim of endodontic treatment is to encourage the healing of apical periodontitis, or to prevent it from occurring if it was not present prior to treatment. Apical periodontitis is a general term used to describe an inflammatory response to irritation caused by the contents of a root canal system and it has several distinct forms. The most common is a granuloma but this can develop into other disease entities such as an abscess, a periapical pocket cyst or a true cyst, all of which present as radiolucencies. However, periapical radiolucencies may also be caused by extra-radicular infections, foreign body reactions and periapical scars, or they may be due to other tumours and cysts that have not originated from pulp disease. Practitioners must recognize and understand the different pathological entities and the dynamic interactions that occur in the periapical tissues in order to correctly diagnose and treat these conditions.