Effectiveness of Oral Hygiene Instructions Given in Computer-Assisted Format versus a Self-Care Instructor.

BACKGROUND: This randomized, single-blinded, controlled study compares the effectiveness of two modes of delivering the same set of oral hygiene instructions: those loaded on a computer-assisted teaching format versus those given personally by a self-care instructor. METHODS: 60 participants with mild to moderate periodontitis were randomized to either the computer-teaching format or the self-care instructor. Plaque score and bleeding indices were assessed at baseline and at 4 week re-evaluation to compare the instructional modalities. RESULTS: At baseline, there was no difference in the parameters between the two groups. At re-evaluation, all parameters were significantly improved compared to baseline; however, there was no difference between any parameters in the computer group versus the instructor. Plaque score was significantly different between younger and older participants, such that participants under 50 years old had lower plaque scores when they received instructions using the computer format (72.5 ± 12.6 vs. 87.2 ± 10.4; p < 0.001). Additionally, in those under-50 year olds, plaque scores were significantly better in the group using the computer format (87.2 ± 10.4 vs. 78.3 ± 15.6; p = 0.03). CONCLUSION: Computer teaching formats and self-care instructors are both effective means of communicating oral hygiene instructions. Computer-assisted instruction format effectiveness may amplify as the population ages. Applications of computer formats teaching oral hygiene instructions and cost effectiveness comparison studies warrant significant future investigation.

The Association between the Anatomic Landmarks of the Pulp Chamber Floor and the Prevalence of Middle Mesial Canals in Mandibular First Molars: An In Vivo Analysis.

INTRODUCTION: The present study aimed to determine the incidence and anatomic variation of the middle mesial (MM) canal in mandibular permanent first molars using cone-beam computed tomographic imaging and to evaluate the association between the presence of MM canals and anatomic landmarks of the pulp chamber floor in the mesial root. METHODS: In this in vivo cross-sectional study, 210 CBCT scans of mandibular fist molars from 210 patients were included. CBCT scans were evaluated in 3 sections, and the following data were collected for further analysis: identification of the MM canal, the distance between the mesiobuccal (MB) and mesiolingual (ML) orifices, the presence of any isthmus between the MB and ML orifices, and the MB and ML root canal system (RCS) configurations. Binary logistic regression was performed to assess the effect of pulp floor anatomic characteristics as an independent variable on the outcome variable (the presence of an MM canal). RESULTS: The overall prevalence of the identification of an MM canal regardless of age was 14.7%. Mandibular first molars with an isthmus between the MB and ML RCS configurations were almost 5 times more likely to show an MM canal (P < .05, odds ratio [OR] = 4.9). The MB-ML intraorifice distance was inversely associated with the presence of an MM canal (P < .05, OR = 0.73). Patients less than 42 years old were 4 times more likely to have an MM canal in their CBCT scans compared with patients older than 42 years old (P < .05, OR = 3.9). CONCLUSIONS: The suggested anatomic landmarks of the pulp chamber floor could act as a reliable predictive factor for the presence of an MM canal. This knowledge of anatomic clues may serve to better direct endodontists in locating an MM canal, which could prevent excessive removal of tooth structures.

Bladder function in mice with inducible smooth muscle-specific deletion of the manganese superoxide dismutase gene.

Manganese superoxide dismutase (MnSOD) is considered a critical component of the antioxidant systems that protect against oxidative damage. We are interested in the role of oxidative stress in bladder detrusor smooth muscle (SM) in different disease states. In this study, we generated an inducible, SM-specific Sod2(-/-) mouse model to investigate the effects of MnSOD depletion on the function of the bladder. We crossbred floxed Sod2 (Sod2(lox/lox)) mice with mice containing heterozygous knock-in of a gene encoding a tamoxifen-activated Cre recombinase in the SM22α promoter locus [SM-CreER(T2)(ki)(Cre/+)]. We obtained Sod2(lox/lox),SM-CreER(T2)(ki)(Cre/+) mice and injected 8-wk-old males with 4-hydroxytamoxifen to induce Cre-mediated excision of the floxed Sod2 allele. Twelve weeks later, SM-specific deletion of Sod2 and depletion of MnSOD were confirmed by polymerase chain reaction, immunoblotting, and immunohistochemistry. SM-specific Sod2(-/-) mice exhibited normal growth with no gross abnormalities. A significant increase in nitrotyrosine concentration was found in bladder SM tissue of SM-specific Sod2(-/-) mice compared with both wild-type mice and Sod2(+/+), SM-CreER(T2)(ki)(Cre/+) mice treated with 4-hydroxytamoxifen. Assessment of 24-h micturition in SM-specific Sod2(-/-) mice revealed significantly higher voiding frequency compared with both wild-type and SM-specific Cre controls. Conscious cystometry revealed significantly shorter intercontraction intervals and lower functional bladder capacity in SM-specific Sod2(-/-) mice compared with wild-type mice. This novel model can be used for exploring the mechanistic role of oxidative stress in organs rich in SM in different pathological conditions.

In vitro comparison of apical leakage in root canals obturated with 0.04 and 0.02 tapered gutta-percha.

INTRODUCTION: Gutta-percha is the most commonly used material for root canal obturation; it has been recently manufactured with different tapers. The aim of this in vitro study was to compare microleakage of canals obturated with standard gutta-percha (0.02 taper) or the new 0.04 taper gutta-percha master cone using the cold lateral condensation technique. MATERIALS AND METHODS: Forty-four extracted single rooted teeth were selected. The crowns were removed and all the canals were prepared using RaCe rotary files. The teeth were then divided into experimental (n=2) and control (n=2) groups. In the first study group, the teeth were obturated with 0.02 taper gutta-percha master cone and lateral condensation. In the second study group, the canals were obturated by 0.04 tapered master cones and the same obturation method. The degree of leakage was measured using fluid filtration method. Data were analyzed statistically by student t-test. RESULTS: There was no significant difference between the mean microleakage of two experimental groups (P=0.558). CONCLUSION: Lateral condensation technique using 0.04 tapered master cones can provide an effective apical seal similar to 0.02 gutta-percha cones.

Clinical and Radiographic Evaluation of Success Rate with MTA Plug in Open Apices.

INTRODUCTION: The ideal endodontic treatment for the teeth with in complete root-ends and necrotic pulps may involve the use of material which forms an immediate apical barrier instead of long term calcium hydroxide therapy. Such procedure may lead us to a single appointment endodontic treatment. The purpose of the present study was to evaluate clinical and radiographic success rate in necrotic teeth with open apices treated with MTA as an apical plug. MATERIALS AND METHODS: Thirty five patients between the ages of 8-16 with total number of 41 necrotic anterior teeth containing open apices were selected. In the first visit, root canals were debrided and filled with calcium hydroxide. After one week, calcium hydroxide was removed and MTA with the thickness of 3 to 4 mm was put in the apical region of the canals. After 24 hours, the remaining part of the canals was filled with guttapercha and sealer and the teeth were restored with composite. All the cases were evaluated clinically and radiographically after 3 and 6 months and data were analyzed by McNemar test. RESULTS: No clinical symptoms were observed in 97.6% of the teeth after 3 months and in none after 6 months. The study showed a significant difference from pretreatment status. After 3 months radiographic evaluation showed that in 17 cases (41.5%), lesions were reduced and in 14 cases (34.1 %), lesions remained the same, and in 10 cases (24.4%) lesions disappeared. After 6 months in 21 cases (51.2%), lesions were reduced, in 3 cases (7.3%) lesions remained the same and in 17 cases (41.5%) lesions disappeared. These finding were statistically different from pretreatment data. CONCLUSION: The results indicate that MTA can be used as an apical plug in the teeth with open apices following root canal debridement and disinfection with calcium hydroxide. Further investigations with longer follow-ups are recommended in order to evaluate the effect of this material.

A comparative study of lidocaine and lidocaine- mannitol in anesthetizing human teeth with inflamed pulps.

INTRODUCTION: Failure to achieve adequate and profound anesthesia in teeth with acute pulp inflammation is a common condition during emergency visits in root canal therapy. Many different anesthetic solutions such as morphine and capsaicin have accordingly been examined. Mannitol- an alcoholic sugar with high osmotic pressure level- is applicated for reducing intracranial and post retinal pressure in medicine. It has also been used for its diuretic effect. In combination with local anesthetic solution, it increases permeability of the nerve fiber sheath and leads to influx of the local anesthetic through cytoplasmic membrane .The purpose of the present study was to compare the efficacy of routine local anesthesia with or without using mannitol in teeth with inflamed pulps. MATERIALS AND METHODS: one hundred patients with acute dental pain in posterior teeth were selected. Vials with 3 ml anesthetic solution containing 2.5% lidocaine with 1/80000 epinephrine or 2.5% lidocaine with 1/80000 epinephrine and 0.5 mol mannitol were used for anesthesia. For each patient, the routine injection technique was applied, during the removal of decay and dentine. Depth of anesthesia was evaluated and the supplementary injection was done in case of pain feeling and then pulpotomy was done. The analysis of data was done using chi-square statistical test. RESULTS: The results showed that complete anesthesia after the first injection was obtained with lidocaine mannitol in 46% and with lidocaine alone in 38% of cases. However, the difference was not significant. CONCLUSION: These finding suggest that the addition of mannitol to the standard anesthetic solution could insignificantly increase the level of anesthesia in teeth with inflamed pulps.