Biomedical subjects

K Gulabivala

Publications and source records attributed to K Gulabivala.

At least 19 recordsLinked to original sources

PubMed2006

Incidence and behaviour of Tn916-like elements within tetracycline-resistant bacteria isolated from root canals.

INTRODUCTION: Tetracycline resistance is commonly found in endodontic bacteria. One of the most common tetracycline-resistance genes is tet(M), which is often encoded on the broad-host-range conjugative transposon Tn916. This study aimed to determine whether tet(M) was present in bacteria isolated from endodontic patients at the Eastman Dental Institute and whether this gene was carried on the transferable conjugative transposon Tn916. METHODS: The cultivable microflora isolated from 15 endodontic patients was screened for resistance to tetracycline. Polymerase chain reactions for tet(M) and for unique regions of Tn916 were carried out on the DNA of all tetracycline-resistant bacteria. Filter-mating experiments were used to see if transfer of any Tn916-like elements could occur. RESULTS: Eight out of 15 tetracycline-resistant bacteria isolated were shown to possess tet(M). Furthermore, four of these eight were shown to possess the Tn916-unique regions linked to the tet(M) gene. Transfer experiments demonstrated that a Neisseria sp. donor could transfer an extremely unstable Tn916-like element to Enterococcus faecalis. CONCLUSIONS: The tet(M) gene is present in the majority of tetracycline-resistant bacteria isolated in this study and the conjugative transposon Tn916 has been shown to be responsible for the support and transfer of this gene in some of the bacteria isolated.

Bacteria↗

PubMed2005

An in vitro evaluation of the ability of ozone to kill a strain of Enterococcus faecalis.

AIM: To evaluate the potential of ozone as an antibacterial agent using Enterococcus faecalis as the test species. METHODOLOGY: Ozone was produced by a custom-made bench top generator and its solubility in water determined by ultraviolet (258 nm) spectrophotometric analysis of solutions through which ozone was sparged for various time-periods. The antibacterial efficacy of ozone was tested against both broth and biofilm cultures. Ozone was sparged for 30, 60, 120 and 240 s, through overnight broth cultures of a strain of E. faecalis (E78.2) and compared with those that were centrifuged, washed and resuspended in water. Enterococcus faecalis (E78.2) biofilms were grown on cellulose nitrate membrane filters for 48 h and suspended in water through which ozone gas was sparged with stirring for 60, 120 and 240 s in a standard fashion. In a separate test, biofilms were also exposed to gaseous ozone. Sodium hypochlorite (NaOCl) was used as a positive control. All experiments were repeated four times. RESULTS: There were significant (P < 0.05) reductions of bacteria in the unwashed (2 log(10) reductions) and washed (5 log(10) reductions) broth cultures following 240 s applications. Biofilms incubated for 240 s with ozonated water showed no significant reduction in cell viability attributable to ozone alone, whereas with NaOCl no viable cells were detected over the same time. Gaseous ozone applied for 300 s had no effect on these biofilms. CONCLUSIONS: Ozone had an antibacterial effect on planktonic E. faecalis cells and those suspended in fluid, but little effect when embedded in biofilms. Its antibacterial efficacy was not comparable with that of NaOCl under the test conditions used.

Anti-Bacterial Agents↗

PubMed2005

Prevalence of persistent pain after endodontic treatment and factors affecting its occurrence in cases with complete radiographic healing.

AIMS: To (i) determine the prevalence of persistent dento-alveolar pain following nonsurgical and/or surgical endodontic treatment conducted in a teaching dental hospital and (ii) identify the risk factors associated with persistent pain after apparently successful root canal treatment. STUDY DESIGN: A total of 175 patients/teeth were reviewed 12-59 months following treatment. The patients were examined clinically and radiographically and a detailed pain history obtained. Multiple logistic regression analysis was used to investigate the association between potential risk factors and persistent pain after successful endodontic treatment. RESULTS: The prevalence of persistent pain after successful root canal treatment was 12% (21/175). Treatment success was determined by the absence of clinical and radiographic signs of dental disease. The factors that were significantly (P < 0.05) associated with persistent pain following endodontic treatment were: 'duration of preoperative pain' [odds ratio (OR) = 8.6], 'preoperative pain from the tooth' (OR = 7.8), 'preoperative tenderness to percussion' (OR = 7.8), 'previous chronic pain problems' (OR = 4.5), 'gender' (OR = 4.5) and 'history of painful treatment in the orofacial region' (OR = 3.8). 'Type of treatment received (surgical or nonsurgical treatment)' showed borderline significance at the 10% level. CONCLUSIONS: The presence and duration of preoperative pain from the tooth site, lasting at least 3 months, a positive history of previous chronic pain experience or painful treatment in the orofacial region, and female gender were important risk factors associated with persistent pain after successful endodontic treatment.

Adolescent↗

PubMed2005

Effect of customization of master gutta-percha cone on apical control of root filling using different techniques: an ex vivo study.

AIMS: (i) To compare the prevalence of extrusion of root filling material when placed using different root filling techniques, with or without customization of the master gutta-percha (GP) cone; and (ii) to investigate the effects of some factors influencing root filling extrusion and presence of voids. METHODOLOGY: A total of 180 roots were selected, prepared and randomly allocated to three groups. Five general dental practitioners performed the root fillings; each filled one group of roots (n = 60) using each of three techniques; 'cold lateral compaction' (n = 20), 'warm vertical compaction' (n = 20) and 'continuous-wave' (n = 20) techniques. For each obturation technique, the master GP cone was customized using chloroform in 10 samples. Two groups of the roots were recycled to allow all five operators to fulfill their remit. Two observers, blind to operator and obturation technique, examined the radiographs (master apical file, post-obturation) to determine the presence of root filling extrusion and voids within the apical 5 mm, independently. Root filling extrusion was also confirmed by direct inspection of the root apex after obturation. The data were analysed using logistic regression models. RESULTS: A total of 300 root fillings were performed; nine were excluded from the analysis. Most of the root fillings (80%, n = 233) were placed within 0.5 mm of the working length; only 20% (n = 58) were placed >0.5 mm beyond the working length. The odds of prevalence of extrusion (>0.5 mm) were significantly reduced by about 50% when cold lateral compaction or customization of GP were used. One operator produced 2.5 times more extruded root fillings than others. Curvature & length of root canal, apical size of prepared canal, as well as operator's preferred obturation technique had no significant influence on the prevalence of extrusion. Customization of GP was the sole factor to significantly reduce the prevalence of voids within the apical 5 mm of working length. CONCLUSIONS: Root filling extrusion was significantly influenced by 'operator' and was reduced by cold lateral compaction and customization of the master cone. Customization of master cone was the only factor that reduced voids apically.

Clinical Competence↗

PubMed2004

Prevalence of and factors affecting postpreparation pain in patients undergoing two-visit root canal treatment.

AIM: This longitudinal, prospective study (i) investigated the prevalence of postpreparation pain during root canal treatment and (ii) evaluated the influence of factors affecting the pain experience. METHODOLOGY: Twenty practitioners, comprising general dental practitioners, MSc graduates and endodontists, participated in this study. The patient sample (n=272) was derived from consecutive patients attending the practitioners' surgeries for a two-visit root canal treatment on a single tooth. Demographic, medical history, preoperative and intraoperative data as well as pain experience on days 1 and 2 after root canal preparation were recorded. Intensity of pain experienced was recorded on a visual analogue scale (VAS) of 0-5. The data were analysed using logistic regression models. RESULTS: The prevalence of postpreparation pain within 48 h after treatment was 64.7% (n=176), but less than 10% of patients experienced severe pain (VAS 4 or 5) on either day 1 or day 2. The presence of preoperative pain (OR=2.841, P<0.001), tooth type (OR=2.008, P=0.009), systemic steroid therapy for other medical reasons (OR=0.181, P=0.023) and preoperative swelling (OR=2.433, P=0.040) were the only factors to significantly influence postpreparation pain experience. CONCLUSIONS: The prevalence of postpreparation pain was high, and the important prognostic determinants were presence of preoperative pain, tooth type, systemic steroid therapy and preoperative swelling.

Adult↗

PubMed2004

Ultrasonic condensation of gutta-percha: the effect of power setting and activation time on temperature rise at the root surface - an in vitro study.

AIM: To determine the effect of power setting and duration of activation on the temperature rise at the root surface during root canal obturation by ultrasonic condensation of gutta-percha. METHODOLOGY: A human maxillary canine was used in an in vitro split tooth model to allow repeated obturation of the root canal system using an ultrasonic device to thermocompact gutta-percha. Combinations of power settings (1, 3 and 5) and durations of activation (4, 10 and 15 s) were used to test their effect on temperature rise at the root surface using eight K-type thermocouples at the mid-root and apical levels. At the end of each obturation, the tooth was disassembled to remove the gutta-percha in preparation for the next obturation (n = 10 for each combination). Multiple linear regression models were used to investigate the effects of power setting, duration of activation and thermocouple location on the maximum temperature rise recorded. RESULTS: Only one combination of power setting (5) and duration of activation (15 s) resulted in temperature rise in excess of 10 degrees C. The maximum temperature rise at the mid-root level was significantly (P < 0.001) greater than that recorded apically. It is also significantly affected by the combination of power setting and duration of activation. CONCLUSIONS: Temperature rises at the root surface during ultrasonic condensation of gutta-percha in excess of 10 degrees C were evident in only one combination of power (5) and time (15 s) settings at the mid-root level.

Body Temperature↗

PubMed2004

Prevalence of and factors affecting post-obturation pain in patients undergoing root canal treatment.

AIM: This longitudinal, prospective study (1) investigated the prevalence of post-obturation pain after root canal treatment and (2) evaluated the influence of factors affecting the pain experience. METHODOLOGY: Twenty practitioners, comprising general dental practitioners, MSc graduates and Endodontists, participated in this study. The patient sample (n = 415) was derived from consecutive patients attending the practitioners' surgeries for root canal treatment on a single tooth. Demographic, medical history, preoperative and intra-operative data as well as pain experience on day 1 and day 2 after root canal obturation were recorded. Intensity of pain experienced was recorded on a visual analogue scale (VAS) of 0-5. The data were analysed using logistic regression models. RESULTS: The prevalence of post-obturation pain within 48 h after treatment was 40.2% (n = 167) but less than 12% of patients experienced severe pain (VAS 4 or 5) on either day 1 or day 2. The factors that significantly influenced post-obturation pain experience were: gender (OR = 0.434, P < 0.001), tooth type (OR = 1.733, P = 0.007), size of periapical lesion (OR = 0.493, P = 0.004), history of post-preparation pain (OR = 4.110, P = <0.001) or generalized swelling (OR = 3.435, P = 0.005) and number of treatment visits (OR = 2.604, P < 0.001). CONCLUSIONS: The prevalence of post-obturation pain was high (40.2%). The important prognostic determinants of post-obturation pain were female, molar tooth, size of periapical lesion smaller than 3 mm, history of post-preparation pain or generalized swelling and single-visit treatment.

Adult↗

PubMed2004

Cultivable microbial flora associated with persistent periapical disease and coronal leakage after root canal treatment: a preliminary study.

AIM: To identify the cultivable bacterial flora in root filled teeth with persistent periapical lesions and to locate their distribution within the root canal system using an in vitro sampling protocol. METHODOLOGY: Eight freshly extracted root filled teeth were collected from the Oral and Maxillo-facial Surgery Department, Eastman Dental Hospital. Seven teeth were associated with persistent apical periodontitis and also showed evidence of coronal leakage. Teeth were transferred to an anaerobic chamber immediately after careful extraction and sectioned transversely to give a crown (in all but one case) and two root segments (coronal and apical). Two samples were obtained from each segment, one from dentine and the other from the restoration or gutta-percha (GP) root filling (46 sites in total). The samples were dispersed, serially diluted and cultured on blood agar and fastidious anaerobic agar (with 5% defibrinated horse blood). The primary growth was subcultured to obtain pure isolates, which were identified by routine microbiological techniques and commercial enzyme tests. RESULTS: A total of 252 strains were isolated from all the teeth. Of all the isolates, the most prevalent bacteria were Gram-positive facultative anaerobes 189/252 (75%) with staphylococci (48/252, 19%), streptococci (44/252, 17%), enterococci (20/252, 8%) and Actinomyces species (20/252, 8%) being found in most of the teeth (6/8, 6/8, 5/8, 5/8 and 7/8, respectively). Of the obligate anaerobes (17%), peptostreptococci (7%) were also present in most teeth (7/8). A statistical association between bacterial flora and site (crown/coronal/apical) or surface (dental/GP/restoration) could not be shown. CONCLUSIONS: The predominant group of bacteria in root filled teeth with persistent apical periodontitis and coronal leakage was Gram-positive facultative anaerobes of which staphylococci followed by streptococci and enterococci were the most prevalent.

Adult↗

PubMed2004

Root canal obturation by ultrasonic condensation of gutta-percha. Part II: an in vitro investigation of the quality of obturation.

AIM: To compare the quality of root canal obturation using ultrasonic or cold condensation of gutta-percha and to determine the effect of power setting and activation time on the quality of obturation using the former technique. METHODOLOGY: An extracted human maxillary canine was used in an in vitro split tooth model to allow repeated obturation of the same root canal system using an ultrasonic device to thermocompact gutta-percha without sealer. After each obturation, the root filling was removed from the tooth to allow evaluation of its quality and for the tooth to be re-obturated. The influence of combinations (n = 10 per combination) of power setting (1, 3, 5) and activation times (4, 10, 15 s) was tested on the quality of root filling, assessed by measuring the voids within the body of the root filling as well as at the surface. Image analysis was used to quantify the voids within the body of the root filling. Cold lateral condensation of gutta-percha served as a control. RESULTS: Both surface and cross-sectional analyses revealed that different power setting and activation time combinations produced significantly fewer voids than cold lateral condensation (P < 0.05) at the apical, mid-root and coronal levels. CONCLUSIONS: Taking surface and cross-sectional analysis together only power setting 5 and activation times of 10 and 15 s consistently produced ultrasonically thermocompacted root canal fillings with fewer voids than cold lateral condensation without sealer.

Cold Temperature↗

PubMed2004

Effectiveness of electrochemically activated water as an irrigant in an infected tooth model.

AIM: To test the effectiveness of electrochemically activated aqueous solutions in the debridement of Enterococcus faecalis biofilms in root canals of extracted teeth. METHODOLOGY: Extracted, human, single-rooted teeth (198) assembled into 11 sets (n = 18) with matching anatomical characteristics were randomly assigned to eight experimental groups. After decoronation, the root canals were prepared to a standard size. Enterococcus faecalis biofilms were grown in the root canals of autoclaved, individually mounted teeth over 48 h. Electrolysed saline collected as anolyte at the anode and catholyte at the cathode were the test agents. The four ultrasonication and four without ultrasonication irrigant groups included: neutral anolyte (NA) (pH 6.5), acidic anolyte (AA) (pH 3.0), catholyte (C) (pH 11.5) and C alternated with neutral anolyte (C/NA). Phosphate-buffered saline (PBS) with and without ultrasonication formed negative and NaOCl (3%) positive control groups. After irrigation, root canal samples were serially diluted, cultured and enumerated. The data were analysed as ratios of residual colony-forming units (CFUs) in PBS versus the test irrigants and using multivariate regression. RESULTS: The NA and NA (ultrasonicated, U), C/NA and AA (U) groups had significantly (alpha = 0.05) less and C (U) and C/NA (U) significantly (alpha = 0.05) more bacteria (CFUs mL(-1)) compared with their respective PBS controls. Ultrasonicated C/NA had significantly (alpha = 0.05) higher CFU counts than the nonultrasonicated solution. Other comparisons between ultrasonic and nonultrasonic groups were not significant. Of the nonultrasonicated groups, C/NA and NA were most effective, whilst of the ultrasonicated groups, AA and NA were most effective. None of these was as effective as 3% NaOCl. CONCLUSIONS: All but two groups (AA and C) were significantly different from their PBS controls. There was a significant difference between the C/NA groups with and without ultrasonication but not between other combinations. NA (U) and AA (U) were the most effective test solutions but NaOCl (3%) gave by far the highest bacterial kills.

Colony Count, Microbial↗

PubMed2003

A comparative study of selected physical properties of five root-canal sealers.

AIM: To investigate selected physical properties of five root-canal sealers. METHODOLOGY: The solubility, film thickness, flow, working and setting times of Roth 801, Tubli-Seal EWT, AH Plus, Apexit and Endion were evaluated. Solubility was measured by weight change of standard specimens in water over a 3-month period. Film thickness was measured as the distance between weighted glass slides containing a standard quantity of sealer. Flow was assessed by rate of sealer extrusion through a standard bore diameter, after unit time. Working time was taken as the point at which flow rate was reduced by 10%. The indentation test using a modified Gilmore needle was employed to investigate the setting times. RESULTS: AH Plus was the least soluble, whilst Apexit was the most unstable in water. The solubility values in increasing order were: AH Plus<Tubli-Seal EWT<Endion<Apexit. Also, AH Plus had the highest film thickness. All sealers showed comparable flow rates. The working time varied from 50 min for Endion to over 2 h for AH Plus and Tubli-Seal EWT. The range of setting times recorded was from 70 min for Tubli-Seal EWT to 8 days for Roth 801. CONCLUSIONS: 1. AH Plus showed the greatest stability in solution and Tubli-Seal EWT performed well, but Apexit and Endion had higher solubility values. 2. The film thickness values in increasing order were: Tubli-Seal EWT<Apexit<Endion=Roth 801<AH Plus. 3. The flow rates for all sealers were similar. 4. The working times for all sealers were greater than 50 min. 5. Roth 801 did not set when incubated in volumes sufficient to fill the test matrices.

Calcium Hydroxide↗

PubMed2002

Effects of sodium hypochlorite solution on root dentine composition.

Sodium hypochlorite (NaOCl) solution,<or=5% w/v available chlorine (abbreviated subsequently to %), is widely used as an irrigant in root canal treatment of teeth, so its effects on dentine are of clinical importance. The effects of approximately 0.5%, 3% and 5% NaOCl solution on the composition of root dentine were studied at ambient temperature. For dentine powder treated for 30 min, depletion of the organic phase was confirmed by infrared spectroscopy. Apatite lattice parameters showed no significant change, but NaCl was also detected by X-ray powder diffraction. The low solubility of apatite mineral in the NaOCl solutions was demonstrated by the constant weight of bulk enamel specimens immersed for seven days. The stability of the mineral phase was confirmed by scanning microradiography (SMR), an X-ray attenuation method employing photon counting. Repeated SMR measurements of the local mineral content of bulk samples of root dentine and a synthetic hydroxyapatite aggregate during exposure to pumped NaOCl solutions for 100 h showed no mineral loss. As predicted from apatite chemistry, reaction of NaOCl with the mineral phase can be excluded as a primary factor in changes in mechanical properties of treated dentine. Effects of retention of NaCl on endodontic sealants requires further investigation.

Journal Article↗

PubMed2002

External cervical resorption associated with localized gingival overgrowth.

AIM: To describe the presentation and management of an unusual lesion of external cervical resorption. SUMMARY: The salient features of this unusual presentation of the external cervical resorption with localized gingival overgrowth, and the resorption located almost wholly on the labial aspect of a maxillary incisor crown are described. Extensive loss of enamel had occurred. The management and possible aetiology of the resorptive lesion are discussed. KEY LEARNING POINTS: Localized gingival overgrowth can be associated with external cervical resorption.The cervical resorption does not necessarily indicate pulp canal infection and the need for root-canal treatment.

Adult↗

PubMed2002

Root and canal morphology of Thai mandibular molars.

AIM: To investigate the root and canal morphology of 351 mandibular permanent molars collected from an indigenous Thai population. METHODOLOGY: The cleaned teeth were accessed, the pulp dissolved by sodium hypochlorite under ultrasonication and the pulp system injected with Indian ink. The teeth were rendered clear by demineralization and immersion in methyl salicylate. The following observations were made: (i) number of roots and their morphology; (ii) number of root canals per tooth; (iii) number of root canals per root; (iv) root canal configuration in each root using Vertucci's classification, with additional modifications; and (v) presence and location of lateral canals and intercanal communications. RESULTS: Of 118 mandibular first molars, 13% had a third disto-lingual root. In three-rooted teeth, 80% of the main distal roots and 100% of the disto-lingual roots had type 1 canal systems. Of 60 mandibular second molars, 10% had C-shaped roots, the majority of which had type 1 (33%) or type IV (33%) canal systems. Of 173 third molars, 68% had two separate roots, 20% had fused roots and 11% had a single C-shaped root; the majority had two canals (61%). CONCLUSIONS: This study suggests that Thai molars exhibit features of both Caucasian and Chinese teeth.

Asian People↗

PubMed2002

An in vitro comparison of the bactericidal efficacy of lethal photosensitization or sodium hyphochlorite irrigation on Streptococcus intermedius biofilms in root canals.

AIM: To compare the bacterial killing of Streptococcus intermedius biofilms in root canals using lethal photosensitization with various combinations of photosensitizer concentration and laser light dose or 3% sodium hypochlorite (NaOCl) irrigation. METHODOLOGY: Extracted teeth (n = 35) with single canals were selected and the canals prepared to apical size 25 with a 10% taper. The teeth were autoclaved and the canals inoculated with Streptococcus intermedius in brain heart infusion broth and were incubated for 48 h to allow a biofilm to form. The teeth were then subjected to 3% NaOCl irrigation (n = 4) or lethal photosensitization using combinations of a range of toluidine blue O (TBO) photosensitizer concentrations (12.5, 25, 50, 100 microgram/mL-1) and light doses (60, 90, 120, 300, 600 s equivalent to energy doses of 2.1-21 J) using a 35-mW helium-neon low power laser targeted at the access cavity (n = 4 for each combination). Controls consisted of laser light only (TBO = 0 microgram/mL-1) (n = 4), TBO only (light dose = 0 s) (n = 4), and no treatment (positive control n = 17). Following treatment the canal contents were sampled with sterile paper points, the sample was dispersed in transport medium, serially diluted and cultured on blood agar to determine the number of colony forming units (CFU). RESULTS: The combination of 100 microgram/mL-1 TBO and 600 s (21 J) of laser energy achieved maximum reduction in recovered viable bacteria (5 log10 CFU). TBO at low concentrations (< or =50 microgram/mL-1) was not bactericidal but treatment with 100 microgram/mL-1 TBO alone reduced recovered viable bacteria by 3 log10 CFU. Laser light alone had limited bactericidal effect. No viable bacteria were recovered following treatment with 3% NaOCl. CONCLUSIONS: The combined use of a photosensitizing agent and a low power laser directed at the access cavity was bactericidal to S. intermedius biofilms in root canals but was unable to achieve total kill, unlike 3% NaOCl.

Biofilms↗

PubMed2002

Prevalence of yeasts in saliva and root canals of teeth associated with apical periodontitis.

AIMS: To determine: (i) the relative prevalence and diversity of yeasts in salivary and root canal samples from the same patients; and (ii) the clinical factors associated with their presence in saliva and root canals. METHODOLOGY: Sixty root canal samples from teeth associated apical periodontitis and the corresponding whole unstimulated saliva samples were obtained from 55 patients. The medical history including antibiotic therapy and clinical/radiographic data on the teeth were recorded. The samples were serially diluted and cultured on yeast & fungi-selective sabouraud dextrose agar. Isolates were characterized and speciated by the germ tube formation test, hyphal morphology and a commercial biochemical test kit (Rapid ID32C(R) system). RESULTS: Twenty-three yeast isolates were recovered from 19 saliva samples and eight isolates from six root canal samples. Candida albicans (17/23 & 3/8) and Rodotorula mucilaginosa (2/23 & 4/8) were the most prevalent isolates from saliva and root canal samples. It was significantly (13.8 times) more probable that yeasts would be recovered from root canals when they were also present in the saliva (P = 0.021). The effect of coronal restoration leakage (P = 0.08) and previous root canal treatment (P = 0.123) were equivocal. The history of antibiotic therapy had no association with the presence of yeasts in saliva (OR = 1.1). CONCLUSIONS: Yeasts occurred relatively infrequently (10%) in root canals. Their presence in root canals was significantly associated with their presence in saliva. The role of yeasts in the initiation and perpetuation of periapical disease remains to be determined.

Anti-Bacterial Agents↗

PubMed2002

Monitoring pulp vitality after transplantation of teeth with mature roots: a case report.

AIM: To initiate discussion on the value of routine root canal treatment for transplanted teeth. SUMMARY: Autotransplantation is an accepted treatment option to replace missing teeth. It is generally considered that revascularization of the pulp following such a procedure is more favourable in teeth with immature roots. In teeth with closed apices root canal treatment is considered necessary. This paper presents a case of pulp revascularization in a transplanted tooth with mature roots and casts doubt on whether root canal treatment is essential in such situations. An alternative treatment protocol is proposed. KEY LEARNING POINTS: * Following transplantation original pulp tissue may survive the operation. * Teeth with obliterated pulp space do not become necrotic more often than those without obliteration. * Monitoring the tooth is an acceptable alternative to automatic root canal treatment for transplanted teeth. * Root canal treatment should be undertaken only upon occurrence of pathological signs.

Adolescent↗

PubMed2002

Root and canal morphology of Thai maxillary molars.

AIM: To investigate the root and canal morphology of 268 maxillary permanent molars collected from an indigenous Thai population. METHODOLOGY: The cleaned teeth were accessed, the pulp dissolved by sodium hypochlorite under ultrasonication, and the pulp system injected with Indian ink. The teeth were rendered clear by demineralization and immersion in methyl salicylate. The following observations were made: (i) number of roots and their morphology; (ii) number of root canals per root; (iii) root-canal configuration in each root using Vertucci's classification with additional modifications; and (iv) presence and location of lateral canals and intercanal communications. RESULTS: All the maxillary first and second molars had three separate roots. Only, half (51%) of the maxillary third molars had three separate roots; the other half had fused or conical roots. The majority of the distobuccal (98.1-100%) and palatal (100%) roots had type I canals. Over half of the mesiobuccal roots of first (65%) and second (55%) molars had two canals. The most common (44.2%) canal configuration in mesiobuccal roots of first molars was type IV (two canals, two foramina). A variety of canal types were found in the mesiobuccal roots of second molars. Maxillary third molars showed the greatest diversity of canal morphology. There was an increase in the prevalence of lateral canals towards the apical part of the roots and intercanal communications were present in 16% of each of first, second and third Thai maxillary molars. CONCLUSIONS: The mesiobuccal roots of Thai maxillary molars possessed a variety of canal system types. Over 50% of the first molars had a second mesiobuccal canal. The palatal and distobuccal canals mainly had type I canals. Only, a small proportion (7.3-13.3%) of the roots exhibited lateral canals which were the most common in the apical third

Carbon↗