Diabetes Mellitus and the Dental Pulp
I. B. Bender and A. B. Bender
Bacteroides forsythus in Primary Endodontic Infections as Detected by Nested PCR
José F. Siqueira Jr. and Isabela N. Rôças
Calretinin Expression in Odontogenic Cysts
Adriano Piattelli, Massimiliano Fioroni, Giovanna Iezzi and Corrado Rubini
Adrenergic Regulation of Capsaicin-sensitive Neurons in Dental Pulp
Kenneth M. Hargreaves, Douglass L. Jackson and Walter R. Bowles
The Antimicrobial Effect of MTAD: An In Vitro Investigation
Mahmoud Torabinejad, Shahrokh Shabahang, Raydolfo M. Aprecio and James D. Kettering
Inductively Coupled Plasma-Emission Spectroscopy and Atomic Absorption for the use of Elemental Analysis of a Root Canal after Lasing with a Holmium: YAG Laser
Allan S. Deutsch, Brett I. Cohen and Barry Lee Musikant
Cementoblasts Maintain Expression of Osteocalcin in the Presence of Mineral Trioxide Aggregate
Troy S. Thomson, Janice E. Berry, Marth J. Somerman and Keith L. Kirkwood
In Vitro Infrared Thermographic Assessment of Root Surface Temperature Rises During Thermafil Retreatment Using System B
Mariusz Lipski, Dr n. med. and Krzysztof Woźniak, Dr n. med.
Antibacterial Efficacy of a New Chlorhexidine Slow Release Device to Disinfect Dentinal Tubules
Shaul Lin, Ofer Zuckerman, Ervin I. Weiss, Yardena Mazor and Zvi Fuss
Extraoral Radiographic Technique: An Alternative Approach
Michael E. Newman and Seymour Friedman
Conventional and Surgical Treatment of a Two-Rooted Maxillary Central Incisor
Ricardo González-Plata-R, and Walter González-Plata-E
Diabetes Mellitus and the Dental Pulp
I. B. Bender, DDS, A. B. Bender, MD
This study attempts to evaluate the oral manifestations of and the limited available dental pulp information on diabetes mellitus, a common metabolic disorder of carbohydrate and lipid metabolism affecting over 16 million Americans. Diabetics are particularly prone to bacterial or opportunistic infections. This vulnerability is caused by a generalized circulatory disorder whereby the blood vessels are damaged by the accumulation of atheromatous deposits in the tissues of the blood vessels lumen. In addition, blood vessels, particularly capillaries, develop a thickened basement membrane, which impairs a leukotactic response, and there is a decrease in the polymorphonuclear leucocyte microbicidal ability and failure to deliver the humoral and cellular components of the immune system. Because the dental pulp has limited or no collateral circulation, it is more prone to be at risk for infection. Clinical and radiographic studies by other investigators have shown that there is a greater prevalence of periapical lesions in diabetics than in nondiabetics. In a study of 252 diabetics with poor glycemic control, a high rate of asymptomatic tooth infection was found. Inflammatory reactions are greater in diabetic states, and the increased local inflammation causes an intensification of diabetes with a rise in blood glucose, placing the patient in an uncontrolled diabetic state. This often requires an increase in insulin dosage or therapeutic adjustment. Removal of the inflammatory state in the periodontium created a need for a lesser amount to insulin for glycemic control. Thus, it is essential to remove all infections including those of the dental pulp. When diabetes mellitus is under therapeutic control, periapical and other lesions heal as readily as in nondiabetics.
Bacteroides forsythus in Primary Endodontic Infections as Detected by Nested PCR
José F. Siqueira, Jr., DDS, MSc, PhD, and Isabela N. Rôças, DDS, MSc
The purpose of this study was to investigate the prevalence of Bacteroides forsythus in primary endodontic infections using a species-specific nested polymerase chain reaction assay. Samples were collected from 50 teeth having carious lesions, necrotic pulps, and different forms of periradiuclar diseases. DNA extracted from the samples was initially amplified using universal 16S rDNA primers. A second round of amplification used the first polymerase chain reaction products to detect a specific fragment of B. forsythus 16S rDNA. B. forsythus was detected in 13 of 22 asymptomatic cases (59.1%), 4 of 10 root canals associated with acute apical periodontitis (40%), and 9 of 18 cased diagnosed as acute periradicular abscesses (50%). There was no relationship between the presence of B. forsythus and the occurrence of symptoms. In general, this bacterial species was detected in 26 of 50 samples of endodontic infections (52%). The findings of this study support the assertion that this bacterial speicies is associated with infections of endodontic origin and suggest that B. forsythus may be involved in the pathogeneses of different forms of periradicular lesions.
Calretinin Expression in Odontogenic Cysts
Adriano Piattelli, MD, DDS, Massimiliano Fioroni, DDS, Giovanna Iezzi, DDS and Corrado Rubini, MD
Calretinin is a calcium-binding protein with a possible role as a calcium buffer, calcium-sensor, or regulator of apoptosis. Calretinin is expressed in neural tissue, is a specific marker of mesothelial cells, and has been demonstrated in the odontogenic epithelium during odontogenesis in rat molar tooth germs. Moreover, it has been found to be expressed in a high proportion of solid, unicystic, and multicystic ameloblastomas, whereas, on the contrary, no positive staining has been found in odontogenic keratocysts, residula cysts, and dentigerous cysts. The purpose of this study was to evaluate calretinin expression in radicular cysts, follicular cysts, orthokeratinized keratocysts, and parakeratinized keratocysts. A total of 70 odontogenic cysts, 24 radicular cysts, 24 follicular cysts, and 22 odontogenic keratocysts (10 orthokeratinized keratocysts, 12 parakeratinized keratocysts) were evaluated. All the radicular cysts, follicular cysts, and orthokeratinized keratocysts were negative. However in 8 of 12 parakeratinized keratocysts, there was a positivity to calretinin in the parabasal-intermediate layers of the cyst epithelium. This positivity to calretinin in the parabasal layers in parakeratinized keratocysts, similar to that found for other markers like PCNA and p53, could point to an abnormal control of the cell cycle and could help to explain the differences in the clinical and pathologic behavior of odontogenic keratocysts, in particular the differences found between orthokeratinized keratocysts and parakeratinized keratocysts.
Adrenergic Regulation of Capsaicin-sensitive Neurons in Dental Pulp
Kenneth M. Hargreaves, DDS, PhD, Douglass L. Jackson, DDS, PhD, and Walter R. Bowles, DDS, MS
Alpha adrenergic agonists (e.g. vasoconstrictors) represent one of the most commonly used drug classes in dentistry. Although adrenergic agonists have potent vascular effects, recent studies suggest that capsaicin-sensitive nociceptors may express adrenoceptors, suggesting that these drugs may directly modulate the function of an important class of pain-signaling neurons in peripheral tissues. In this study, we tested the hypothesis that adrenergic agonists inhibit activation of peripheral terminals of capsaicin-sensitive fibers innervating dental pulp. Pretreatment with epinephrine or clonidine significantly inhibited capsaicin-evoked release of immunoreactive calcitonin gene-related peptide from superfused bovine dental pulp. These studies suggest that adrenergic agonists may reduce postoperative pain in part via a direct inhibition of capsaicin-sensitive nociceptors. This finding may lead to the development of selective, peripherally acting, adrenergic analgesics. Moreover, because neuropeptide release alters blood flow, it is possible tht the vascular effects of these drugs are caused by both vasoconstriction and inhibition of peripheral neuropeptide release.
The Antimicrobial Effect of MTAD: An In Vitro Investigation
Mahmoud Torabinejad, DMD, MSD, PhD, Shahrokh Shabahang, DDS, MS, PhD, Raydolfo M. Aprecio, OD, and James D. Kettering, PhD
Pulp and periradicular diseases are of microbial origin. To effectively clean the root canal system a disinfecting agent must be able to penetrate into difficult-to-reach areas and kill microorganisms with minimal damage to the host tissues. The purpose of this investigation was to test the ability of a mixture of a tetracycline isomer, an acid, and a detergent (MTAD) to kill Enterococcus faecalis and compare its efficacy to that of sodium hypochlorite (NaOCI) and ethylene diamine tetraacetic acid (EDTA). The zones of inhibition and minimum inhibitory concentrations were measured for these solutions. Measurement of zones of inhibitory concentrations showed that MTAD is as effective as 5.25% NaOCI and significantly more effective than EDTA (p < 0.0001). Furthermore, MTAD is significantly more effective in killing E. faecalis than NaOCI when the solutions are diluted (p < 0.0001). Measurement of the minimum inhibitory concentrations demonstrated that although MTAD is still effective in killing E. faecalis at 200x dilution, NaOCI ceases to exert its antibacterial activity beyond 32x dilution. EDTA did not exhibit any antibacterial activity. Based on the results of this study, it seems that MTAD is an effective solution in eradicating E. faecalis.
Inductively Coupled Plasma-Emission Spectroscopy and Atomic Absorption for the use of Elemental Analysis of a Root Canal after Lasing with a Holmium: YAG Laser
Allan S. Deutsch, DMD, Brett I. Cohen, PhD, and Barry Lee Musikant, DMD
It has been reported in the literature that after lasing dentin the dentin surface has a glassy or globular appearance. Many authors believe this to be recrystallized hydroxyapatite. The purpose of this elemental analysis was to see if any of the silica fiber optic was melted and deposited as these globular structures on the canal wall. Two teeth were used. One was hand-instrumented with files and used as the control, the other was lased with a holmium:YAG laser. A 245-μ low OH ˉ fiber was used with a power setting of 0.75 W, 5 Hx, 94.2 J, and 1134 V to lase the root. The roots were microanalyzed for oxygen, phosphorus, silicon, nitrogen, hydrogen, calcium, and carbon. The percentages for all elements tested were the same for both teeth. Therefore, there was no silicon deposited onto the canal wall of the tooth that was lased. It is concluded that the low OH ˉ silica fiber optic was not melted and deposited onto the dentinal canal wall.
Cementoblasts Maintain Expression of Osteocalcin in the Presence of Mineral Trioxide Aggregate
Troy S. Thomson, DDS, MS, Janice E. Berry, BS, Marth J. Somerman, DDS, PhD, and Keith L. Kirkwood, DDS, PhD
This study investigated the effects of mineral trioxide aggregate on cementoblast growth and osteocalcin production in tissue culture. For cellular morphology studies, cemetoblasts on mineral trioxide aggregate, IRM, and amalgam were incubated for 48 h then fixed for scanning electron microscopic analysis. For gene expression on mineral trioxide aggregate and IRM, reverse transcriptase polymerase chain reaction was performed using primer sets for glyceraldehyde-3-phosphate dehydrogenase, type 1 collagen, alkaline phosphatase, osteocalcin, and bone sialoprotein after 3 and 5 days. In vitro matrix protein expression was evaluated by confocal microscopy for the presence of osteocalcin on MTA after 7 and 12 days. Images were compared with controls to assess qualitative differences. Results suggest that mineral trioxide aggregate permits cementoblast attachment and growth and the production of mineralized matrix gene and protein expression. Our data indicates that mineral trioxide aggregate can be considered cementoconductive.
In Vitro Infrared Thermographic Assessment of Root Surface Temperature Rises During Thermafil Retreatment Using System B
Mariusz Lipski, Dr n. med., and Krzysztof Woźniak, Dr n. med.
The purpose of this in vitro study was to measure the temperature rise on the outer root surface during retreatment of Thermafil using the System B HeatSource. Twenty extracted human maxillary premolars were filled with Thermafil with plastic carriers and divided into two groups of 10 teeth each. In goup 1, Thermafil obturators were retrieved using System B HeatSource fitted with a medium plugger at a temperature of 225°C. The plugger was placed first on the buccal, then on the lingual of the plastic carrier for 5 s each. This melted the gutta-percha and softened the plastic carrier. In group 2, Thermafil obturators were retrieved in the same manner except that the heated plugger was placed for 8 s. The temperature changes on the outer root surfaces were recorded using a thermal imaging camera. Themafil retreatment in vitro using a System B HeatSource causes temperature rises ranging from 26.7°C to 46.0°C. This finding could possibly have implications for creating injury of the periodontal tissues.
Antibacterial Efficacy of a New Chlorhexidine Slow Release Device to Disinfect Dentinal Tubules
Shaul Lin, DMD, Ofer Zuckerman, DMD, Ervin I. Weiss, DMD, Yardena Mazor, and Zvi Fuss, DMD
Dentinal tubules of 27 cylindrical bovine root specimens were infected with Enterococcus faecalis. In nine specimens, 5% chlorhexidine was placed in a slow-release device (Activ Point®) for 7 days, in another nine irrigation with 10 ml of 0.2% chlorhexidine was used, and the remaining nine served as positive control. Powder dentin samples obtained from within the canal lumina using ISO 025 to 033 burs were examined for the presence of vital bacteria by inoculating brain-heart infusion plates and counting colony forming units. Results were analyzed using analysis of variance and covariance with repeated measures. Heavy bacterial infection was observed at the layer close the lumen in the control specimens, decreasing rapidly from layer to layer up to the deepest layer tested (400-500 μm), which contained several hundred colony forming units. Viable bacteria in each layer of dentin were significantly reduced with chlorhexidine irrigation solution (p < 0.01) and were completely eliminated with the chlorhexidine slow-release device (p < 0.01).
Extraoral Radiographic Technique: An Alternative Approach
Michael E. Newman, DDS, and Seymour Friedman, DDS
The inability of certain patient populations to accept intraoral films and/or sensors can cause complications in the performance of endodontic therapy. An alternative technique (extraoral film placement) can be used to obtain clinically diagnostic radiographs. This article describes the alternative technique.
Conventional and Surgical Treatment of a Two-Rooted Maxillary Central Incisor
Ricardo González-Plata-R, DDS, MSc, and Walter González-Plata-E, DDS, MSc
Conventional and surgical endodontic management were performed on a two-rooted maxillary central incisor with a periapical lesion. Anatomical complexity of the tooth lead to perforation in the distal root during conventional treatment, thus a surgical approach was taken. A 4-month postoperative radiograph shows repair.