The in vitro antibacterial effect of iodine-potassium iodide and calcium hydroxide in infected dentinal tubules at different time intervals.

AIM: The aim of this study was to evaluate the antibacterial effect of iodine-potassium iodide (IKI) and calcium hydroxide (CH) on dentinal tubules infected with Enterococcus faecalis (E. faecalis) at different time intervals. METHODS AND MATERIALS: Hollow cylinders of bovine root dentin (n=45) were infected and divided into three equal groups filled with either IKI or CH and a positive control. After placing each medicament in the infected cylinders for time periods of 10 minutes, 48 hours and 7 days, microbiological samples were analyzed. At the end of each period, four 100 microm thick inner dentin layers (400 microm thick from each specimen) were removed using dental burs of increasing diameters. Dentin powder was cultured on agar plates to quantitatively assess their infection, expressed in colony forming units (cfu). RESULTS: In all layers of the positive control group, heavy bacterial infection was observed. After 10 minutes, IKI reduced the amount of viable bacteria more efficiently than CH, whereas at later time intervals CH showed the best results. CONCLUSION: For short periods of exposure, IKI has a more efficient antibacterial effect in the dentinal tubules than CH but CH performs better after longer durations of exposure. CLINICAL SIGNIFICANCE: This research indicates the use of IKI is a better choice for disinfecting the root canal than CH if only a short duration of exposure is used because of its more efficient antibacterial effect. However, if a longer exposure time is used, then CH is a better choice because of its better disinfecting effect over time.

Flare-ups after endodontic treatment: a meta-analysis of literature.

The purpose of this study was to determine the frequency of flare-ups and to evaluate factors that affect it by using meta-analysis of results of previous studies. MEDLINE database was searched by using Entrez PubMed search engine and Medical Subject Headings (MeSH) search with EviDents Search Engine to identify the studies dealing with endodontic flare-up phenomenon. The search covered all articles published in dental journals in English from 1966-May 2007, and the relevancy of 119 selected articles was evaluated by reading their titles and abstracts, from which 54 were rejected as irrelevant and 65 were subjected to a suitability test. Six studies that met all the above mentioned criteria were included in the study. Average percentage of incidence of flare-ups for 982 patients was 8.4 (standard deviation +/-57). There were insufficient data to investigate the effect of the influencing factors.

Radiographic evaluation of the prevalence of root resorption in a Middle Eastern population.

OBJECTIVE: To evaluate radiographically the prevalence of various types of root resorption in different tooth groups in a Middle Eastern population. METHOD AND MATERIALS: Full-mouth radiographs of 712 patients (19,072 teeth) were evaluated for the presence of root resorption. Two observers evaluated each tooth from at least 2 radiographic projections on periapical films. RESULTS: Teeth exhibiting root resorption were found in 205 radiographs (28.8%). The most common form of resorption was pulpal infection (71.2%), mainly in mandibular molars ( P< .01) and in patients 45 years and older ( P< .005). Orthodontic pressure resorption was detected in 14.6% of root resorption cases, mainly in maxillary incisors ( P< .01). Impacted tooth or tumor pressure resorption was observed in 10.2% of all cases of resorption, mainly in mandibular molars ( P< .01), and periodontal infection resorption was identified in 3.9% of all resorption cases in all tooth groups ( P > .05). Ankylotic resorption was not found in this survey. CONCLUSION: The most common types of root resorption in the general population were pulpal infection-related root resorption, orthodontic pressure root resorption, and impacted tooth pressure resorption. It is probable that most are unrelated to traumatic injuries of the teeth.

New emphasis in the treatment of dental trauma: avulsion and luxation.

There are several protocols for the successful management of dental trauma emergencies. However, these existing protocols are inconsistent regarding several issues. As the Israeli dental community and patients have specific characteristics, a modified and adaptable protocol was required. This new protocol contains simple and straightforward clinical guidelines, arranged in table format, according to the nature of the trauma. The present study shows the protocol for luxation and avulsion injuries, with new recommendations for the treatment of luxated closed-apex teeth, the preferred at-site treatment and storage medium for avulsed teeth, and the conditioning of the root surface in these cases. To emphasize and explain the modification of this new protocol, research-based information has been incorporated.

Comparison in vivo of the first tapered and nontapered instruments that bind at the apical constriction.

OBJECTIVE: To compare sizes of the first instrument with or without taper that binds to the narrow apical diameter of the root canal after coronal flaring. STUDY DESIGN: For the study, 388 canals were examined in patients with intact apices. A standard endodontic access cavity was prepared and the coronal third flared using standardized K-files, Gates Glidden reamers, or Profile rotary instruments. Apical patency was established using K-file size 10 and working length determined using an apex locator and radiographs. Standardized K-file hand instruments were gently introduced to working length beginning with size 15. The first K-file to bind to the canal walls and reach the working length was recorded as FKFB. Nontapered instruments (Lightspeed) were then gently introduced by hand to each canal in ascending order beginning with size 20 to working length. The first instrument to bind to the canal walls and reach the working length was recorded as FLSB. Statistical analysis was carried out using univariate analysis of variance. RESULTS: The average size of FLSB was approximately 2 ISO sizes larger than FKFB (P < .001). Minimal differences were found in the maxillary central incisors (6.7 +/- 3.0) and maximal differences in canals from maxillary lateral incisors (15.4 +/- 3.5). CONCLUSIONS: The first nontapered instruments to bind at the apical constriction were larger and reflected the actual narrow apical diameter of the canal better than the tapered instruments.

Radiographic features of vertically fractured endodontically treated mesial roots of mandibular molars.

OBJECTIVE: The purpose of this study was to evaluate the most frequent radiographic appearance of bony lesions around endodontically treated vertically fractured mesial roots of mandibular molars. STUDY DESIGN: For the study, 49 extracted mesial roots with vertical fractures (study group) were evaluated and compared to 52 extracted roots without fractures (control). RESULTS: The "halo" (36.7%) and "periodontal" (28.6%) type radiolucencies were the most typical appearances of periradicular areas around the mesial roots of mandibular molars with vertical root fractures. By itself, bifurcation radiolucency was statistically insignificant (6.1%), however in conjunction with other areas of radiolucency, it was significant (63.3%, P < .0378). No radiolucency (38.5%) and periapical radiolucency (32.7%) were predominant features in the control (nonfractured roots). Amalgam dowel in the coronal part (1-2 mm) of the root was found in 67.3% of the vertically fractured roots (P < .0006). Defined but not corticated (57.2%) or diffuse (32.6%) borders were typical for vertically fractured mesial roots. CONCLUSIONS: The use of significant variables, such as "periodontal" and "halo" bony radiolucencies, bifurcation involvement, and the presence of amalgam dowel, has prediction sensitivity of 77.6% (VRF group) and specificity of 82.7% (nonfractured roots).

In vitro antibacterial efficacy of a new chlorhexidine slow-release device.

OBJECTIVE: The aim of this study was to evaluate and compare the antibacterial effect of chlorhexidine and calcium hydroxide slow-release devices on oral bacteria. METHOD AND MATERIALS: The agar diffusion test was used to evaluate the antibacterial effect of the slow-release devices Activ Point (chlorhexidine; Roeko) and Calcium Hydroxide Plus Point (Roeko) on 8 anaerobic and 2 facultative oral bacterial strains, as well as 2 bacterial cultures randomly sampled from necrotic root canals and incubated in anaerobic and aerobic broth for 48 hours. The efficiency of the medicaments against the various strains was evaluated using a nonparametric test (Friedman type) and a second nonparametric test (Wilcoxon's signed rank test). RESULTS: Activ Point produced significantly larger inhibition zones (P < .001) than the calcium hydroxide slow-release device around all tested bacterial strains. CONCLUSION: The chlorhexidine slow-release device (Activ Point) exhibited significant antibacterial activity in the agar diffusion test and merits study as an intracanal medicament.

Physician and emergency medical technicians' knowledge and experience regarding dental trauma.

The purpose of the present study was to evaluate the knowledge of physicians and emergency medical technicians (EMT) regarding primary treatment for dental trauma and to assess the experience they have in treating dental injuries. The study population consisted of 70 military physicians and EMT during their military service. A questionnaire was distributed relating to demographic data, such as age, gender, position, and type of military service, as well as the following issues: past experience in treating or witnessing dental trauma, former education regarding diagnosis and treatment of dental trauma, assessment of knowledge regarding dental trauma, etc. Of all participants, only 4 (5.9%), all physicians, received education regarding dental trauma. Nevertheless, 42 (61.8%) reported they witnessed such an injury during their military service. Dental injuries were first seen by the EMT in 41.2% of the cases, by the physician in 25%, and by a dentist in only 7.3%. Overall, 58 (85.3%) of the physicians and EMT stated that it was important to educate the primary health care providers regarding diagnosis and treatment of dental trauma. Special emphasis should be given to providing primary caregivers with the relevant education to improve their knowledge and ability of dealing with diagnosis and treatment of dental trauma.

Retrospective evaluation of surgical endodontic treatment: traditional versus modern technique.

The aim of this retrospective study was to compare the outcome of surgical endodontic treatment preformed using the traditional versus modern techniques. There were 110 patients who were treated by surgical endodontic treatment between 2000 and 2002 and evaluated from their dental charts. The surgical endodontic treatment was preformed using a traditional or modern technique. The traditional technique included root-end resection with a 45 degrees bevel angle, and retrograde preparation using a carbide round bur. The modern technique included root-end resection with minimal or no bevel, and retrograde preparation using ultrasonic retro-tips with the aid of a dental operating microscope. The retrograde filling material for both techniques was intermediate restorative material. There were 71 patients with 88 treated teeth that were compatible with the inclusion criteria. Complete healing rate for the teeth treated with the modern technique (91.1%) was significantly higher than that for teeth treated using the traditional technique (44.2%) (p < 0.0001). In the traditional technique a significant (p = 0.032) negative influence of the tooth type was found. Modern surgical endodontic treatment using operative microscope and ultrasonic tips significantly improves the outcome of the therapy compared to the traditional technique.

Dentinal pH changes following electrophoretically activated calcium hydroxide ions in the root canal space of bovine teeth.

The aim of the study was to evaluate pH changes of external root dentin surface at different depths following electrophoretic activation of calcium hydroxide (CH) in the root canals. For the study, 60 cavities were drilled on three external root surfaces of 20 bovine teeth specimens to obtain remaining dentin thickness (RDT) of 0.3, 0.7 and 1.0 mm. CH paste was inserted in the lumens. In the experimental group (10 specimens) CH paste was electrophoretically activated. Microelectrode was used to measure pH changes in the cavities immediately after placement of CH, following electrophoretical activation, and after 30 days storage. A significant (P < 0.05) increase in pH following electrophoresis was found in all specimens in the experimental group. Cavities with 0.4 mm RDT showed a maximal pH increase to the value of 11.3 +/- 0.4. In the control group no change in pH was observed after 3 min. A similar increase in pH was observed in both groups after 30 days. The pH changes were significantly depended on the RDT (P < 0.05) in all groups. Electrophoretically activated CH could significantly increase dentinal pH of external root surface within minutes up to 30 days.

Comparison of quality of life after surgical endodontic treatment using two techniques: a prospective study.

OBJECTIVE: The purpose of this prospective study was to compare patient experience of quality of life following surgical endodontic treatment using 2 different techniques: a technique that included the use of a dental operating microscope, root resection with minimal bevel and retrograde preparation with ultrasonic tips, and a traditional technique that included root resection with a 45 degrees bevel and retrograde preparation by bur performed without magnification. STUDY DESIGN: The study consisted of 66 patients referred for surgical endodontic treatment. One operator (I.T.) carried out all treatment. An equal number of patients were assigned to each group. Group 1 was treated by the traditional technique without an operating microscope and Group 2 by a technique using an operating microscope and minimal osteotomy. All patients were given a questionnaire with 15 questions to evaluate their quality of life for 7 days postsurgery. RESULTS: On day 5, patients in Group 1 reported significantly more pain and took significantly more analgesics (P < .05). On days 1 and 2, patients in Group 2 reported significantly more difficulty in mouth opening, mastication, and the ability to speak (P < .05). CONCLUSION: Patients in both groups reported a high incidence of symptoms. The technique using the operating microscope provided significantly less postoperative pain, but more difficulties in mouth opening, mastication, and the ability to speak immediately postoperatively.

Effect of electrophoretically activated calcium hydroxide on bacterial viability in dentinal tubules--in vitro.

To evaluate the ability of electrophoretically activated calcium hydroxide (CH) to eliminate bacteria in dentinal tubules. In an in vitro model of dentinal tubule infection, 18 cylindrical root specimens prepared from freshly extracted bovine teeth were used. After removal of the smear layer, intracanal dentinal tubules were infected with Enterococcus faecalis for 21 days. In 12 specimens, CH paste was placed in the root canals for 7 days. In six of these, an electrophoretic current (10 mA per 10 min), using two electrodes, was applied after placing the medicament in the canal. Powder dentin samples obtained from within the canal lumina using ISO 025, 027, 029, 031 and 033 burs were examined for the presence of vital bacteria by inoculating agar plates and counting colony forming units. anova with repeated measures was used to analyze results. A significant difference was found between experimental groups and the positive control group. CH and electrophoretically activated CH significantly (P <0.001) reduced bacterial viabilities in dentinal tubules to a depth of 200 microm. Treatment with electrophoresis was significantly (P <0.001) more effective than pure CH in depths of 200-500 microm. Specimens treated with electrophoretically activated CH showed no viable bacteria in dentinal tubules to a depth of 500 microm from the root canal space within 7 days. The time required for treatment of pulpal infection root resorption may be decreased, thus minimizing the risk of coronal fractures in young patients with traumatized teeth.

Comparison of procedural errors resulting during root canal preparations completed by senior dental students in patients using an '8-step method' versus 'serial step-back technique'.

OBJECTIVE: To compare procedural errors that occur in patients during root canal preparation by senior dental students using a new '8-step method' versus the traditional 'serial step-back technique.' STUDY DESIGN: Senior dental students treated 221 root canals of maxillary and mandibular teeth. Instrumentation included coronal flaring with Gates-Glidden reamers and standardized stainless steel K-files in all teeth. A new 8-step method was used to prepare 67 canals using standardized stainless steel hand instruments (8-step SS) and 69 canals using the rotary Nickel Titanium instruments (8-step NiTi). The traditional serial step-back technique (step-back) was used for 85 root canals. In the apical third, reaming or filing motions were used up to sizes 25 and only reaming motion in sizes larger than 25 with the new 8-step method. A filing motion was used in the step-back for all sizes. Root canals of all groups were obturated with gutta-percha points and AH26 using a lateral condensation technique. Pre- and postoperative radiographs were taken of each tooth. Procedural errors were recorded and statistically analyzed using a binomic test for comparison of proportion. RESULTS: Procedural errors detected consisted of 2 canals with transportation (3%) with the 8-step SS, and 3 canals (4%) with transportation with 8-step NiTi. There were no canal obstructions or instrument separations. With the step-back, 20 canals were transported (24%), 7 canals had obstructions (8%), and in 1 canal instrument was separated (1%). CONCLUSIONS: The new 8-step method resulted in fewer procedural errors than the traditional serial step-back technique when senior students prepared root canals in patients either by hand with standardized K-files or by rotary NiTi instrumentation.

Reduction of viable bacteria in dentinal tubules treated with clindamycin or tetracycline.

AIM: We sought to evaluate and compare the antibacterial effect of clindamycin and tetracycline in bovine dentinal tubules. METHODS: Dentinal tubules of 32 cylindrical bovine root specimens were infected with Streptococcus sanguis N1. Clindamycin 2% or tetracycline 2% (Ledermix) was placed in the root canal for 1 week. Powder dentin samples obtained from within the canal lumina by using International Standards Organization No. 25 to No. 31 burs were examined for the presence of vital bacteria after the brain-heart infusion plates were inoculated and the colony-forming units were counted. The potent effect of the medicaments was also evaluated through the use of the agar diffusion test. RESULTS: Heavy bacterial infection was observed in the control bovine root specimens at the layer close to the lumen. This decreased rapidly from layer to layer up to the deepest layer tested (300-400 microm), which contained several hundred colony-forming units. Clindamycin significantly reduced the amount of viable bacteria in each dentin layer compared with the positive control and tetracycline (P <.01). The agar diffusion test, wherein dilutions in increments of 1/3 and 1/9 were used, revealed that both medicaments had antibacterial activity, but clindamycin was significantly better. In the 1/27 dilution, clindamycin had a minor effect and tetracycline had no effect at all. CONCLUSION: Under the experimental conditions used in this study, the commercial preparations of clindamycin were more effective than those of tetracycline (Ledermix) in the agar diffusion test and clindamycin penetrated into dentinal tubules up to 400 microm. Thus, it has the potential to serve as an effective intracanal medicament in persistent infections when other medicaments fail.

Analysis of postoperative symptoms following surgical endodontic treatment.

OBJECTIVE: The purpose of this prospective study was to analyze postoperative pain and swelling of patients undergoing surgical endodontic treatment using a strict protocol incorporating measures to control postoperative symptoms. METHOD AND MATERIALS: The study consisted of 82 patients referred for surgical endodontic treatment. All surgical procedures were performed using a microsurgical technique employing strict protocol. All patients were premedicated with a single dose of oral dexamethasone (8 mg) preoperatively and two single doses (4 mg) 1 and 2 days postoperatively. Antibiotics were prescribed selectively only when severe symptoms were present due to infection. Patients were administered chlorhexidine mouthwash twice daily starting 3 days before the operation and an additional 7 days postoperatively starting the day after surgery. Cold compresses were applied on the skin at the site of surgery intermittently every 15 minutes during the operative day. Pain and swelling were recorded pre- and postoperatively, and the influence of different variables on postoperative sequelae were analyzed. RESULTS: One day postoperatively, 76.4% of the patients were completely pain free, less than 4% had moderate pain, and 64.7% did not report any swelling. The preoperative symptoms significantly influenced the pain experience post-surgery. CONCLUSION: There was a low incidence of postoperative pain and swelling following endodontic surgical treatment according to protocol with measures to control postoperative signs and symptoms. Patients with preoperative pain were more likely to have postoperative pain.

Residual dentin thickness in mesial roots of mandibular molars prepared with Lightspeed rotary instruments and Gates-Glidden reamers.

OBJECTIVE: We sought to measure the residual dentin thickness (RDT) in the mesial roots of mandibular molars after instrumentation with Lightspeed and Gates-Glidden rotary instruments. Study design Thirty extracted, untreated human mesial roots of mandibular molars were separated from the distal roots and embedded in clear polyester resin. The roots were cut horizontally at 1, 4, and 7 mm short of the anatomic apex. The diameter of each mesiobuccal canal was measured by using a stereo measuring microscope at each level in the buccolingual and mesiodistal directions. The dentin thickness was measured in each level in the mesial, distal, buccal, and lingual directions. Sections were reassembled with a muffle. The canals were enlarged to the working length with Lightspeed rotary instruments, of which the average size used was a No. 50 file. The coronal third was flared with No. 2 Gates-Glidden reamers. Slices were separated again, and the RDT and canal diameters were measured. RESULTS: The minimal measured RDT after instrumentation at the 1-, 4-, and 7-mm levels was 0.70 +/- 0.28 mm, 1.04 +/- 0.18 mm, and 1.09 +/- 0.19 mm, respectively. The average diameter of the canals after instrumentation at the 1-, 4-, and 7-mm levels was 0.50 +/- 0.04 mm, 0.52 +/- 0.05 mm, and 0.74 +/- 0.08 mm, respectively. The canal diameter did not exceed one third of the root diameter at all levels. CONCLUSIONS: Root canal preparation of mandibular mesial roots with Lightspeed instruments to No. 50 in the apical third and Gates-Glidden reamers to No. 2 in the coronal third does not significantly decrease the RDT.

Root resorption--diagnosis, classification and treatment choices based on stimulation factors.

Etiology of different types of root resorption requires two phases: mechanical or chemical injury to the protective tissues and stimulation by infection or pressure. Injury can be similar in various types of root resorption. The selection of proper treatment is related to the stimulation factors. Intrapulpal infection is the stimulation factor in internal root resorption and external periradicular inflammatory root resorption. Adequate root canal treatment controls intrapulpal bacteria and arrests the resorption process. In cervical root resorption, infection originates from the periodontal sulcus and stimulates the pathological process. As adequate infection control in the sulcus is unlikely, removal of granulation tissue from the resorption lacuna and sealing are necessary for repair. Removal of the stimulation factor, i.e. pressure, is the treatment of choice in root resorption related to pressure during orthodontic treatment, or an impacted tooth or tumor. In ankylotic root resorption, there is no known stimulation factor; thus, no predictable treatment can be suggested. Therefore, various types of root resorptions can be classified according to the stimulation factors: pulpal infection resorption, periodontal infection resorption, orthodontic pressure resorption, impacted tooth or tumor pressure resorption, and ankylotic resorption.

Antibacterial efficacy of a new chlorhexidine slow release device to disinfect dentinal tubules.

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 to the lumen in the control specimens, decreasing rapidly from layer to layer up to the deepest layer tested (400-500 microm), 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).