|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
||||
|
|
Author: Costa G. Journal: JOE , vol. 27, September 2001 Reviewer: Pranav Vohra, D.M.D. Purpose: To use radiosorbant test inhibition analysis to examine if raw gutta-percha, raw gutta-balata, or seven clinically used GP products actually release proteins that cross-react with Havea latex (natural latex protein). Materials &Methods:
Results: There was no cross reactivity between the negative control, gutta-percha, and synthetic trans-polyisopropene. Both the positive control and gutta-balata extract showed cross reactivity with the havea latex allergen specific human IgE antibody. Discussion:
|
|
Author: Sobrinho, et.al. Journal: JOE 27 (10):605, Sept. 2001 Prepared by: Greg Dearing, D.M.D. Purpose: To determine whether microorganisms recovered from infected human root canals were able to survive and translocate* to a local lymph node when experimentally inoculated into the root canal system of germ free mice. *translocation: the passage of viable indigenous bacteria from a given site to the regional lymph nodes and other organs 3 Mechanisms
Materials and Methods:
Results:
Conclusions: Selective mechanisms occur in which some bacterial species are fit to survive, multiply, and translocate in the germ free mouse model. |
|
Author: Grecca, Fabiana Soares et. al. Journal: Journal of Endodontics, 27(10):610, September 2001 Reviewer: Donna Salin, D.M.D. Purpose: To evaluate the effects of two calcium hydroxide pastes and two sealers used in endodontic treatment, on the periradicular repair of teeth, via radiographic evaluation. Materials and Methods:
Results: The periapical lesions al all groups were statistically similar at the beginning of treatment. To evaluate the decrease in the periapical radiolucent areas the final values were compared with initial values for each experimental group. At 360 days, the lesions of groups I to III had a statistically similar reduction in size, whereas group IV had a smaller reduction in lesion size (p < 0.05). Discussion: Calcium hydroxide associated with PMCC (composition: 2.5 calcium hydroxide, 1 g zinc oxide p.a., 0.05 g colophony, 2 ml polyethylene glycol 400, and 0.04 g camphorated p-monochlorophenol) allows a controlled liberation of calcium and hydroxyl ions. This material forms calcium p-chlorophenolate, which maintains a high pH and allows the liberation of calcium and hydroxyl ions for a longer period, which may be the reason for its good results independent of the sealer used. Aqueous vehicles, such as Calasept paste, have a rapid ionic dissociation of the ions and consequently short-term action, which may explain the poorer results seen with Calasept paste (when used with the AH Plus sealer in Group IV). The antibacterial action of Sealapex is related to the calcium and hydroxyl ionization and also to the maintenance of the high pH in tissues, even after setting. The antibacterial action of Sealapex and its biocompatibility can explain the good results obtained by the sealer when associated with both of the calcium hydroxide pastes.
|
|
Week of November 12, 2001 |
|
Journal: JOE: 27(10): 616-619, September 2001 Author: Prepared by: Lance Isaac, D.M.D. Purpose: The purpose of this study was to evaluate the effectiveness of chlorhexidine- or antibiotics-based medications in eliminating E. faecalis biofilms. Materials and Methods: Biofilms of E. faecalis were induced on cellulose nitrate membrane filters. Nine membranes were used for each Mitis salivarius agar plate, which were then incubated for either 1d or 3d at 37° C in an aerobic atmosphere. The antimicrobial medications tested in gel form were:
In the biofilm susceptibility assay, 1mL of each of these medications were used to cover each biofilm-containing membrane. Uncovered biofilm membranes served as controls for adhered/lost cells (=microorganisms). Six biofilm membranes were used for each group. Treated biofilms were aseptically transferred to vials containing a neutralizing agent in saline solution and vortexed for 1min. Suspensions were 10-fold diluted, seeded onto Mitis salivarius agar plates and the colony-forming units (CFU) counted after 48h of aerobic incubation at 37° C. Only a, b and e were tested against the 3d biofilms. Results/Discussion: Among 1d biofilms, a, b, e and f significantly reduced the number of viable bacterial cells in the biofilms. However, only chlorhexidine-containing medications (a, b and e) were able to completely eliminate most of the biofilms. Set d. and the control did not affect the biofilm, while c allowed bacterial overgrowth. Because of the results of the 1d biofilm, only a, b, and e were tested against 3d biofilms, and all 3 were found to eliminate or at least reduce the bacterial load (no significant differences among them).
|
|
Journal: JOE 2001; 27(10): 624-6 Author: Kleier DJ Reviewer: Kimberly Pham, DMD Purpose: To describe how the endodontic
surgeon and surgical assistant work as a team to effectively and efficiently
use this technique. Technique:
Advantages:
Disadvantages: If any sutures pull through the tissue, the integrity of the suture line could become compromised. Inform patient this possibility Discussion: CLST can be used to close
Sutures should be kept in place only long enough to ensure initial healing
by primary intension. (For intrasulcular incision, junctional epithelium repopulate after 48 hours) |
|
Title: A comparison of mesial molar root
canal preparations using two engine-driven instruments and the balanced-force
technique Author: Imura et al. Journal: JOE: 27(10): 627-631, October 2001. Submitted by: Paul Slusarz, D.M.D. Purpose: To compare the effects of two engine-driven, nickel-titanium instrument systems with hand files in the final shape of slight and moderately curved canals. Materials & Methods:
Results:
Discussion: This study attempted to evaluate several aspects of two new endodontic rotary instruments and one hand instrumentation to prepare canals with slight and moderate curvatures. In this study, on the average, all techniques instrumented all four walls analyzed, leaving just a few specimens with untouched walls. |
|
Title: Removal of fractured posts using ultrasonic vibration: an in vivo study. Author: Smith BJ, et al. Journal: JOE 2001; 27(10): 632 Reviewer: Mark Wang, Purpose: To determine the effectiveness of ultrasonic vibration in the removal of fractured posts from teeth under true clinical conditions. Material & Methods:
Results & Conclusion:
|
|
Week of November 19, 2001 |
|
Title: Influence of rotational speed, torque and operator’s proficiency on ProFile failures Author: G.M. Yared, F.E. Bou Dagher, & P. Machtou Journal: International Endodontic Journal: 34: 47-53, 2001 Reviewer: Donna Salin, D.M.D. Purpose: To evaluate the influence of rotational speed, torque, and operator experience with a specific Ni-Ti rotary instrumentation technique on the incidence of locking, deformation and separation of instruments. Materials &Methods:
Results: In the 1st group only 1 instrument was deformed in the 150 rpm group and no instruments separated or locked. In the 250 rpm group instrument separation did not occur. A high incidence of locking, deformation, and separation was noted in the 350 rpm group. In general, instrument sized 30-15 locked, deformed, and separated. Overall, there was a trend toward a higher incidence of instrument deformation and separation in smaller instruments. In the 2nd group, neither separation nor deformation and locking occurred during the use of the ProFile instruments at any of the different torque values. In the 3rd group, analysis demonstrated that significantly more instruments separated with the least experienced operator. Instrument locking, deformation, and separation did not occur with the most experienced operator. Discussion: Deformation and separation occurred during the final passage of PRI in the last (tenth) canal in each subgroup of the 1st group. That may be due to the fact that the operator, being aware it was the final passage, not adhere strictly to the guidelines and applied excessive apical pressure on the instrument. In the 2nd group, neither deformation nor separation occurred. This was probably due to the low speed of 150 rpm as well as the strict adherence to the clinical guidelines and the minimal load exerted on the instruments. The inexperience operator in the 3rd group probably exerted excess apical pressure on the PRI and/or used them for too long in the canal. Consequently, the PRI locked into the canal and were subjected to high level torque. Overall, training in the use of the PRI technique, a speed of 150 rpm, and adherence to specific guidelines were all crucial in avoiding instrument separation and reducing the incidence of instrument locking and deformation.
|
|
Author: Jenkins, SM., Hayes, SJ. Dummer, PMH. Journal: International Endo Journal, 34, 16-22, Jan. 2001 Key Words: dental practice, endodontics, Reviewed by: M. Pallante, D.M.D. Purpose: To gather both quantitative and qualitative information on
the nature of root canal treatment carried out by a group of dentists working
within the Materials and Methods: 720 graduates from the Results: Two hundred ninety-nine questionnaires containing
useful information were returned.
Discussion: The authors are careful to say that this data
cannot be considered representative of the general dental population in the |
|
Title: A survey of interfacial forces used during endosonic instrumentation of root canals Journal: International Endodontic Journal, 34, 54-62, 2001 Author: Regan et al. Reviewed by: Andy Schoelch, DDS Purpose: To examine and measure the pattern of interfacial forces acting between root canal dentin and ultrasonic files during endosonic instrumenatation using K-files sizes 15, 20, and 25. Materials and Methods: Single rooted teeth were mounted on a cantilevered aluminum beam to which two pairs of single element strain gauges were joined in a half bridge configuration mounted at right angles to each other. The strain gauges were connected to an analogue-to-digital converter fitted in a microcomputer via a conditioning amplifier. This enabled strains to be recorded as a function of interfacial forces over a period of time. Twenty operators instrumented root canals using sizes 15, 20, and 25 ultrasonically energized K-type files. The lateral forces generated were calculated. Results:
Conclusion: The range of forces measured is broader than previously reported and may have a bearing on uncontrolled dentin removal, even during ultrasonically activated irrigation.
|
|
Title: Aetiology of root canal treatment failure: why well-treated teeth can fail Author: Siqueira, J.F. Journal: International Endodontic Journal 34(1):1-10, 2001 Reviewed by: Alison Morrison, D.M.D. Purpose: To discuss the aetiology of the failure of root canal treatment and to discuss the indications for the treatment of endodontic failures. Literature review: Endodontic therapy usually fails when the treatment is not carried out to the highest standards; however, there are times when high quality root canals result in failure. Root canal treatment commonly fails due to secondary intraradicular infection, extraradicular infection or for other nonmicrobial reasons. Other Intrinsic and extrinsic nonmicrobial factors have also been discussed as reasons for endodontic treatment failure. Conclusion: The literature suggests that persistent intraradicular, secondary infections, and in some instances extraradicular infections are the major causes of failure of both poorly treated and well-treated root canals. Seltzer et al.1963, Sjogren 1996 and Engstrom et al. 1964 - Root canal treatment fails when treatment falls short of acceptable standards. Nair et al. 1990 and Lin et al 1992 - The major factors associated with endodontic failure are the persistence of microbial infection in the root canal system and or the periradicular area. Reasons for failure:
Kakehashi et al. - Microorganisms colonizing the
root canal system play an essential role in the pathogenesis of periradicular lesions. Moller et al. 1981 - Demonstrated in monkeys
that only devitalized pulps that were infected induced periradicular
lesions. Sundquivst 1976 - Confirmed the important role of bacteria in periradicular lesions in a study using human teeth. Bystrom et al. 1987, and Sjogren et al. 1997 - Showed that if microorganisms persist in the root canal at the time of root filling of if they penetrate into the canal after filling, there is a higher risk that the treatment will fail. Lin et al 1991 and Siqueira et al. 1996 - Demonstrated that part of the root canal space often remains untouched during chemo-mechanic preparation, regardless of technique and instruments employed. Atlas 1997 - Under conditions of phosphate starvation triggered by low concentrations of organic phosphates, cells turn on genes for utilization of organic phosphate compounds and for the scavenging of trace amounts of inorganic phosphate. Untreated teeth usually are composed of mixed infections ( predominately gram – anaerobic rods) and failed cases are composed of only one or a few species ( usually gram +). Jett et al. 1994, Siqueira & Uzeda 1996 and Siqueira &Lopes 1999 - E faecalis strains have been demonstrated to be extremely resistant to several medicaments, including calcium hydroxide. Molander et al. 1998 - When E. faecalis is established in the root canal, its eradication by conventional means may be extremely difficult.
Sundqvist & Reuterving 1980, Nair 1984, Happonen 1986, Sjogren et al. 1988 and Sakellariou 1996 - It is currently recognized that some oral organisms, such as Actinomyces spp. and Propionebacterium propionicum may be implicated in extraradicular infections. Costerton et al. 1987 and Siqueira & Lopes 1998 - A biofilm can be defined as a microbial population attached to an organic or inorganic substrate, surrounded by microbial extracellular products, which form an intermicrobial matrix. Costerton et al. 1987, 1994 and Gilbert et al. 1997 - Organized in biofilms, microorganisms show higher resistance to both antimicrobial agents and host defense mechanisms when compared with planktonic cells. Tronstad et al. 1990 - Reported the occurrence of bacterial biofilms adjacent to the apical foramen and bacterial colonies located inside periradicular granulomas.
Strindberg 1956, Engstrom et al. 1964 - Success rate of the root canal treatment is decreased in cases of overfilling. Conversely, it has been reported that the apical extent of the root canal filling has no correlation with treatment failure (Lin et al. 1992). Barbosa et al. 1993, Spangberg 1998 and Lopes & Siqueira 1999 - Most of the materials used in root canal obturation are either biocompatible or show cytotoxicity only prior to setting. Yusuf 1982 - The presence of infected dentine or cementum chips in the periradicular lesion has been associated with impaired healing.
Saunders and Saunders 1994 - It has been found that coronal leakage may be an important cause of failure of endodontic treatment. Siqueira et al. 1999 - Recontamination
of the root canal system by coronal leakage will occur through: sealer
dissolution by saliva, percolation of saliva in the interface between sealer
and root canal walls and /or between sealer and gutta-percha.
Nair et al. 1998 - It has been demonstrated that cholesterol crystals can be an etiologic factor in nonresolving chronic inflammation. Although it has been revealed that the majority of periradicular cysts heal after conventional root canal therapy (Morse et al. 1975), it has been suggested that true cysts, which contain cavities completely enclosed by epithelial lining, do not (Nair et al. 1993). Treatment of Endodontic Failure: Only one of the factors discussed above, intraradicular infection, can be managed by retreatment of the root canal.
|
|
Week of November 26, 2001 |
|
Author: Lee, et.al Journal: Dental Traumatology, 17 (5):231 October, 2001 Reviewer: Pranav Vohra, D.M.D. Purpose: To report the case of using laser Doppler Flowmetry (LDF) for monitoring traumatized teeth. Report: The case is of a 7 y.o., male with non-contributory medical history, who presented with a 4 mm laterally luxated #9, presenting 16 hours after a football accident. Patient was anesthetized with 3% prolocaine w/out epi to maintain vasculature to the teeth. The teeth were repositioned using a soft orthodontic arch wire, and patient placed on chlorhexidine twice a day and penicillin VK 250 mg for 7 days. At the 10th day recall, the patient was asymptomatic, and healing was uneventful, so the splint was removed. Vitality testing:
It was determined that to maintain the possibility of survival of vasculature, the teeth be monitored using LDF. At two weeks post op there were no changes in the vitality testing by cold, and LDF results were noted. At 3 months, #9 was asymptomatic and unresponsive to cold, with #7, 8, 9 being WNL. Radiographically, root development was seen in all four incisors, and the LDF of #9 showed an increasing flux value of 8 A.U. At the six-month recall, all teeth were developing normally, and #9 showed a delayed response to cold, and a metallic sound to percussion indicating possible ankylosis. At, 12 months, all teeth responded normally to cold and LDF on #9 showed a reading of 9A.U. All incisors responded normally to palpation and percussion with 2-3 mm probings, and a metallic percussion sound still evident on #9. Discussion: According to the authors, the technique of using LDF on traumatized teeth gives a much more reliable way of monitoring vitality as compared to the more traditional tests like Endo Ice. |
|
Journal: Dental Traumatology 2001;17 97-102 Reviewer: Nima Dayani, D.D.S. Purpose: This report includes basic information on both prevention and first aid after dental trauma to permanent teeth. Table 1. Treatment guidelines for tooth and bone fractures in the permanent dentition
(1) occlusal
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Author: Flores MT, Andreasen JO, Bakland LK, et al Journal: Dental Traumatology, 17(5):193, October 2001 Reviewer: Joe Simoneaux, DDS Purpose: To develop guidelines for the treatment of traumatic dental injuries Introduction: Studies indicate that 50% of children (most
often 8-12 y/o) sustain a traumatic dental injury. Crown fracture occurs most
frequently as a result of accident, sport activity or violence. Appropriate
treatment given in a timely manner can lessen the oral health and aesthetic
impact. Due to new technology and improved understanding of the inflammatory
process, there is now a more conservative approach in handling dental trauma.
The International Association of Dental Traumatology
had developed the following guidelines as a consensus statement for the
variation in trauma treatment. These guidelines are helpful in assisting
dentists and other healthcare providers in delivering the best care in the
most efficient manner, thus, improving the short and long-term outcome.
Although it is beyond the scope of these recommendations, major facial trauma
of the bone and soft tissue is the critical first step in the overall
management of maxillofacial trauma. Table 1. Treatment guidelines for avulsed teeth with closed apex
Table 3. Follow-up procedures for traumatized permanent teeth
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
|||||
|
Temple University School of
Dentistry. All contents copyright (C) 1996. All rights reserved. |
|
||||
|
|