Treatment Outcome in Endodontics: The Toronto Study. Phase 1: Initial Treatment
Shimon Friedman, DMD, Sarah Abitbol, DDS, and Herenia P. Lawrence, DDS, PhD
Identification of Spirochetes (Treponemens) in Endodontic Infections
J. Craig Baumgartner, DDS, PhD, Saeng-usa Khemaleelakul, DDS, and Tian Xia, DDS
Prevalence of Odontogenic Sinus Tracts in Patients Referred for Endodontic Therapy
Rahul Gupta, DDS, and Gunnar Hasselgren, DDS, PhD
Validity of a Three-dimensional Public-Domain System for Contemporary Endodontic Research
Thomas Stamm, Dr. med. dent., Markus Kaup, Dr. med.dent., Ariane Hohoff, Dr. med. dent., Tobias Meier, ZA, and Ulrich Meyer, Dr. med., Dr. med. dent.
Incidence of Endodontic Treatment: A 48-Month Prospective Study
Michael J. Boykin, DMD, MS, Gregg H. Gilbert, DDS, MBA, Ken R. Tilashalski, DMD, and Brent J. Shelton, PhD
Effect of Dexamethasone on Root Resorption After Delayed Replantation of Rat Tooth
Kee-Yeon Keum, DDS, PhD, Oh-Taik Kwon, DDS, MSD, Larz S. Spängberg, DDS, PhD, Chong-Kwan Kim, DDS, PhD, Jin Kim, DDS, PhD, Moon-II Cho, PhD, and Seung-Jong Lee, DDS, MS
Mineral Trioxide Aggregate (MTA) Solubility and Porosity with Different Water-to-Powder Ratios
Marcela Fridland, DDS, and Rafael Rosado, CHEM ENG
Effect of MTAD on the Bond Strength to Enamel and Dentin
Tanya K. Machnick, DDS, MS, Mahmoud Torabinejad, DMD, MSD, PhD, Carlos A. Munoz, DDS, MSD, and Shahrokh Shabahang, DDS, MS, PhD
Ca2+ Diffusion Through Dentin of Ca (OH)2 Associated with Seven Different Vehicles
Izabel Coelho Gomes Camões, DDS, PhD, Milton Roedel Salles, PhD, and Orlando Chevitarese, DDS, PhD
Evaluation of Antifungal Activity of Mineral Trioxide Aggregate
Saad Al-Nazhan, BDS, MSD, and Aziza Al-Judai, BDS
Comparison of Spreader Penetration During Lateral Compaction of .04 and .02 Tapered Gutta-percha
Brian L. Wilson, DMD, and J. Craig Baumgartner, DDS, PhD
Intracanal Distribution Patterns of Sealers After Lateral Condensation
S. Ryan Facer, BA, and Richard E. Walton, DMD, MS
Interaction Between Sealers and Gutta-percha Cones
Michael Tagger, DMD, MS, Beatrice Greenberg, DMD, and Galit Sela, BS, DMD, MSD
Fracture Resistance of Endodontically Treated Premolars Restored with Ormocer and Packable Composite
Feridun Hürmüzlü, DDS, PhD, Arlin Kiremitçi, DDS, PhD, Ahmet Serper, DDS, PhD, Emre Altundaşar, DDS, and Şeyda Hergüner Siso, DDS
Treatment Outcome in Endodontics: The Toronto Study. Phase 1: Initial Treatment
Shimon Friedman, DMD, Sarah Abitbol, DDS, and Herenia P. Lawrence, DDS, PhD
This study assessed the 4- to 6- yr outcome of initial endodontic treatment during Phase 1 of the “Toronto Study” project. A total of 450 teeth were treated, alternating the “Schilder” technique and step-back with lateral condensation, and examined clinically and radiographically by an independent examiner. Apical periodontitis was recorded as absent (periapical index < 3) or present (periapical index > 3) and outcome dichotomized as “healed” (no apical periodontitis, no signs or symptoms) or “disease.”Univariate, bivariate, and multivariate analyses were performed (p = 0.05) on 120 examined teeth. The “healed” rate (81% overall) was significantly higher for teeth treated without apical periodontitis (92%) than with apical periodontitis (74%). Several other factors were associated with healing rate differential of 10% or higher, but no statistical significance. This study confirmed apical periodontitis as the main prognostic factor in initial endodontic treatment. Continuation of the project will allow assessment of other prognostic factors with better power.
Identification of Spirochetes (Treponemens) in Endodontic Infections
J. Craig Baumgartner, DDS, PhD, Saeng-usa Khemaleelakul, DDS, and Tian Xia, DDS
The purpose of this study was to determine the prevalence of spirochetes in asymptomatic infected root canals and in endodontic abscesses/cellulitis. Aseptic clinical samples were collected using paper points from 54 infected root canals and from aspirates of 84 abscesses/cellulitis. Oligonucleotide primers were produced for PCR identification of Treponema vincentii, T. perctinovorum, T. medium, T. amylovorum, T. denticola, T. maltophilum, and T. socranskill. PCR detected spirochetes in 51 of 84 (60.7%) samples from abscesses/cellulitis and in 20 of 54 (37.0%) samples from asymptomatic infected root canals. T.socranskii was the most frequently detected (44.9%), followed by T. maltophilum (29.7%), T. denticola (28.9%), T. pectinovorum (13.7%), and T. vincentii (5.1%). The number of treponema species detected ranged from 1 to 5 species per sample. The mean numbers of species detected were 2.3 in abscesses/cellulitis and 2.6 in infected root canals. Significant association among species was found between T. maltophilum and T. socranskii, as well as between T. maltophilum and T. denticola by determining the odds ratio (>2.0).
Prevalence of Odontogenic Sinus Tracts in Patients Referred for Endodontic Therapy
Rahul Gupta, DDS, and Gunnar Hasselgren, DDS, PhD
The purpose of this study was to determine the prevalence of odontogenic sinus tracts in patients referred for endodontic therapy. Charts of 330 patients (393 permanent teeth) endodontically treated during a 10-month period were reviewed and data was collected. Among the 393 permanent teeth there were a total of 160 teeth with preoperative status of periradicular inflammation. Of 160 teeth with preperative status of periradicular inflammation, 29 teeth (18.1%) had an odontogenic sinus tract, which correlates to almost one in five teeth with periradicular inflammation having a sinus tract.
Validity of a Three-dimensional Public-Domain System for Contemporary Endodontic Research
Thomas Stamm, Dr. med. dent., Markus Kaup, Dr. med.dent., Ariane Hohoff, Dr. med. dent., Tobias Meier, ZA, and Ulrich Meyer, Dr. med., Dr. med. dent.
The purpose of this study was to evaluate the limits and benefits of a visualization system based on public-domain software for contemporary three-dimensional (3-D) endodontic research purposes. Three-dimensional bio-models of six human teeth and of one bone-implant specimen were generated using cross-sectional imaging. To evaluate the overall performance in processing large data sets and in reproducing accurate 3-D morphology, slices with a thickness varying from 100 μm to 10 μm were cut. Auto-outlining and segmenting techniques were tested. The 3-D bio-models represented in accurate detail the different morphological aspects of the specimen. Voxel volumes of 0.116 x 10-5 mm3 could be realized and were only restricted by the computer hardware limitations. The system is not limited to dental hard tissues. Hypomineralized material and soft tissues as well as bone- and allogenic-implant material could be visualized. The method presented is valid and meets current requirements applying to endodontic research. The broad-based use of high-quality, public-domain software and the resulting exchange of experience help to manage resources and may contribute to enhancing the in-process quality of research.
Incidence of Endodontic Treatment: A 48-Month Prospective Study
Michael J. Boykin, DMD, MS, Gregg H. Gilbert, DDS, MBA, Ken R. Tilashalski, DMD, and Brent J. Shelton, PhD
The purpose of this study was to determine the incidence of endodontic services provided to participants in a longitudinal cohort study. The “Florida Dental Care Study” was a prospective cohort study using a representative baseline sample of 873 dentate adults. An in-person interview and clinical dental exam were conducted at baseline, 24, and 48 months after baseline, with telephone interviews every 6 months between those times. Dental record information was abstracted afterward. Thirteen percent of participants received at least one endodontic procedure after baseline. Endodontic services constituted approximately 2% of all dental procedures performed. Conventional root canal therapy comprised 94% of the endodontic services and was approximately evenly distributed among anterior teeth, premolars, and molars. Retreatment and apicoectomy each accounted for 3% of the endodontic procedures. The most common self-reported reasons for the dental visit in which a root canal occurred were “toothache,” “abscess,” and “dental sensitivity.” A significant percentage of persons received some type of endodontic treatment in this diverse adult sample. Dental abscesses or toothaches were the main reason(s) for endodontic treatment, but not all persons with these conditions during follow-up sought dental treatment of any variety.
Effect of Dexamethasone on Root Resorption After Delayed Replantation of Rat Tooth
Kee-Yeon Keum, DDS, PhD, Oh-Taik Kwon, DDS, MSD, Larz S. Spängberg, DDS, PhD, Chong-Kwan Kim, DDS, PhD, Jin Kim, DDS, PhD, Moon-II Cho, PhD, and Seung-Jong Lee, DDS, MS
The purpose of this study was to evaluate the effect of dexamethasone after delayed tooth replantation with specific regard to root resorption and ankylosis. In addition, the study was planned to elucidate further the usefulness of the model. Fifty-two maxillary first molar teeth were extracted from 26 Sprague-Dawley white female rats fed 0.4% β-aminoproprionitrile for 3 days to facilitate the extraction. After extraction, the mesio-buccal root canals were endodontically treated under a microscope to prevent subsequent inflammatory resorption of pulpal origin and were assigned to three groups. Teeth in group 1, the dexamethasone group (n = 22), were demineralized in citric acid (1 min), washed, soaked in 1000 nM dexamethasone solution (3 min), air-dried, and replanted in the original sockets. Total extraoral treatment time for each tooth was controlled to 30 min. Teeth in group 2, the dried-only group (n = 22), were air-dried for 30 min after obturation without any surface treatment and replanted. Teeth in group 3, the immediate group (n = 8), were extracted, not root-filed and replanted immediately into their sockets. All experimental animals were killed at 3 weeks after replantation and evaluated histologically. Forty-three of the 52 teeth were available for histological interpretation. They consisted of six immediate, 18 dried-only, and 19 dexamethasone-treated teeth. The degree of progressive root resorption was significantly less in the dexamethasone-treated group than in the dried-only group (p < 0.05). The dexamethasone-treated group exhibited significantly more bone ankylosis than the dried-only group (p < 0.05). These results indicate that the topical use of dexamethasone may be of value in reducing the degree or rate of progressive root resorption secondary to traumatic avulsion and that the rat is a reasonable model for tooth replantation.
Mineral Trioxide Aggregate (MTA) Solubility and Porosity with Different Water-to-Powder Ratios
Marcela Fridland, DDS, and Rafael Rosado, CHEM ENG
This study tested mineral trioxide aggregate (MTA) solubility and porosity with different water-to-powder proportions. The study also determined the chemical composition of the salts dissolved by MTA. Four sets of specimens using the following water-to-powder proportions were prepared: 0.26, 0.28, 0.30, and .033 grams of water per gram of cement. The latter is the ratio recommended by the manufacturer. It was determined that the degree of solubility and porosity increased as the water-to-powder ratio increased. Significant differences were found among the sets of specimens. The chemical analyses of the salts dissolved by MTA in the water identified the presence of calcium as the main chemical compound. The pH level of the solution was highly alkaline, ranging between 11.94 and 11.99. It can be stated that the calcium found in the solution should be in its hydroxide state at this high pH level. This ability to release calcium hydroxide could be of clinical significance because it could be related to the proven capacity of MTA to induce mineralization.
Effect of MTAD on the Bond Strength to Enamel and Dentin
Tanya K. Machnick, DDS, MS, Mahmoud Torabinejad, DMD, MSD, PhD, Carlos A. Munoz, DDS, MSD, and Shahrokh Shabahang, DDS, MS, PhD
The purpose of this study was to compare the effect of MTAD (a mixture of a tetracycline isomer [doxycycline], an acid [citric acid], and a detergent [Tween 80]) and phosphoric acid on the bond strength to enamel and dentin using a conventional OptiBond Solo Plus dentin adhesive system. One hundred flat surfaces (50 enamel/50 dentin) were prepared for bonding. Specimens were embedded in acrylic with the flat surface exposed. One of the following surface treatments was applied before bonding composite with Optibond Solo Plus (Kerr Corp): 1 min NaOCI/1 min EDTA; 1 min NaOCI/1 min MTAD; 30 s etch with H3PO4 (positive control), 2 min saline (negative control), or 20 min NaOCI/5 min MTAD (clinical protocol for MTAD). Shear bond strength was tested 30 min after bonding. Data were analyzed using a one-way ANOVA followed by the Student-Newman-Keuls multiple comparison method. Surface pretreatment with acid etch resulted in the greatest enamel bond strengths (p < 0.05). All surface pretreatments were superior to saline for dentinal bonding (p < 0.05). On the basis of our findings, it appears that teeth endodontically treated with the MTAD protocol for clinical use (20 min 1.3% NaOCI/5 min MTAD) may not need any additional dentin conditioning before the application of the dental adhesive.
Ca2+ Diffusion Through Dentin of Ca (OH)2 Associated with Seven Different Vehicles
Izabel Coelho Gomes Camões, DDS, PhD, Milton Roedel Salles, PhD, and Orlando Chevitarese, DDS, PhD
This investigation measured the diffusion of Ca2+ through dentin by using Ca (OH)2 associated with various vehicles. After mechanical preparation and removal of smear layer, 41 human premolar teeth were stored individually in flasks containing 800 ml of ultra-pure deionized water for 2855 h. The Ca2+ concentration was measured by atomic absorption spectrophotometry as a function of time. These measurements were divided into two phases: dissolution, to check the loss of Ca2+ from the tooth structure itself, for which all canals were kept empty and open in the absence of medication for 1168 h, and diffusion, in which the specimens were divided into 10 groups (3control groups: group 1 = water control, group 2 = sealing control, and group 3 = open canal dissolution control; 7 experimental groups in which the whose canals were filled with Ca (OH)2 paste associated with the following vehicles: group 4 = saline; group 5 = polyethylene glycol (Calen); group 6 = glycerin and camphorated parachlorophenol group 7 = camphorated paramonochlorophenol; group 8 = glycerin; group 9 = glycerin and tricresol formaldehyde (TCF); and group 10 = anesthetic solution. This phase lasted 1687 h. A total of 1058 measurements of Ca2+ were made. Regression analysis was used for statistical evaluation. We concluded that diffusion occurred differently for each group: the medications used in the root canals interacted with the dentinal structure or among themselves; the medication coated the dentinal tubule, facilitating the diffusion of Ca2+ into the external part of the root.
Evaluation of Antifungal Activity of Mineral Trioxide Aggregate
Saad Al-Nazhan, BDS, MSD, and Aziza Al-Judai, BDS
The purpose of this investigation was to study, in vitro, the antifungal effect of mineral trioxide aggregate (MTA) using a tube-dilution test. MTA was tested freshly mixed and after 24 h set on Candida albicans. The tested MTA was incubated with C. albicans for 1 h, 24 h, and 3 days. Results showed that the freshly mixed MTA was effective in killing the tested fungi after 1 day of contact, whereas the 24-h set MTA was effective after 3 days of incubation. It was concluded that MTA (freshly mixed and 24-h set) was effective against C. albicans.
Comparison of Spreader Penetration During Lateral Compaction of .04 and .02 Tapered Gutta-percha
Brian L. Wilson, DMD, and J. Craig Baumgartner, DDS, PhD
The purpose of this study was to compare the initial penetration depth of fine-fine nickel-titanium (NiTi) and fine-fine stainless-steel (SS) spreaders during lateral compaction of .02 or .04 tapered master gutta-percha cones and to evaluate the effect of increasing canal curvature on penetration depth. Fifty-one root canals were instrumented to a standardized size and grouped by degree of curvature for comparison. Our results showed that NiTi spreaders penetrated to a significantly greater depth than SS spreaders using .02 tapered gutta-percha in canal curvatures greater than 20 degrees and when using .04 tapered gutta-percha regardless of canal curvature. No significant difference occurred between NiTi and SS-spreader penetration using .02 tapered gutta-percha in canal curvatures of 0 to 20 degrees (p > 0.05). Both NiTi and SS spreaders penetrated to a greater depth as canal curvatures increased to greater than 20 degrees (p < 0.05). Both NiTi and SS spreaders penetrated to a shallower depth with .04 tapered gutta-percha compared with .02 tapered gutta-percha (p < 0.0001).
Intracanal Distribution Patterns of Sealers After Lateral Condensation
S. Ryan Facer, BA, and Richard E. Walton, DMD, MS
The purpose of this study was to examine coverage patterns of sealer on canal walls and between gutta-percha cones after lateral condensation. Ninety extracted teeth with single canals were evenly and randomly divided into three sealer groups (Roth’s, Sealapex, AH 26). Canals were cleaned and shaped, then coated with one of the three sealers followed by lateral condensation of gutta-percha. The teeth were placed into 100% humidity at 37°C. After 4 months the roots were notched and fractured longitudinally and the dentin lifted to expose the gutta-percha sealer and dentin walls. Qualitative assessment was in the apical and coronal as to the amount and the pattern of sealer coverage. Coverage was categorized by the amount and location as follows: (a) no sealer; (b) slight-partial; (c) moderate-partial; or (d) complete coverage. Sealer was frequently absent between gutta-percha cones and the canal wall and at times absent between cones, with a general moderate-partial coverage. No sealer group demonstrated complete coverage; however, AH 26 showed more consistent moderate-partial distribution. Coverage was better in the coronal. In conclusion, none of the three sealers showed a continuous layer between the primary gutta-percha obturant and the canal wall or in spaces between cones.
Interaction Between Sealers and Gutta-percha Cones
Michael Tagger, DMD, MS, Beatrice Greenberg, DMD, and Galit Sela, BS, DMD, MSD
Clinical observations seem to indicate that some gutta-percha cones are softened by contact with sealers. The purpose of the study was to verify whether an interaction existed between some sealers and different brands of gutta-percha cones. Because previous studies have indicted that the differences between brands of gutta-percha are magnified by heat, thermatic compaction was used in conjunction with a model of a root-canal preparation with lateral canals. Three brands of cones (Kerr, UDM, Beldent) were tested with three types of endodontic sealers (AH 26, Apexit, Roth’s). A group without sealer served as a control. The length of flow into the lateral canals was measured for each combination and analyzed by two-way ANOVA. A highly significant difference was found, confirming the hypothesis that an interaction between sealer and cones is present in some combinations. It was not possible to ascribe a trend of greater effect to a certain sealer, but Roth’s 811 had the least effect on flow.
Fracture Resistance of Endodontically Treated Premolars Restored with Ormocer and Packable Composite
Feridun Hürmüzlü, DDS, PhD, Arlin Kiremitçi, DDS, PhD, Ahmet Serper, DDS, PhD, Emre Altundaşar, DDS, and Şeyda Hergüner Siso, DDS
In this study, mesiodistocclusal (MOD) cavity preparations of endodontically treated maxillary premolars that were enlarged to size #50 were restored using three restorative materials (one ormocer, one packable composite, and one high-copper amalgam) and two application techniques (with or without coronal radicular technique). Copper rings were filled with self-curing polymethylmethacrylate resin and the teeth were placed into resin up to the level of the CEJ. The teeth were grouped according to the restorative material and technique, mounted in a Universal Testing Machine, and the buccal walls subjected to a slowly increasing compressive force until fracture occurred. The force of fracture of the walls of each tooth was recorded and the results in the various groups compared. The group restored with packable composite without radicular extension showed the highest resistance to fracture (p < 0.05). Both groups restored with amalgam were significantly weaker than all the other groups (p < 0.05).