Effects of ozone and photo-activated disinfection against Enterococcus faecalis biofilms in vitro.

OBJECTIVES: The purpose of this study was to compare the antibacterial effects of gaseous ozone (O3) and photo-activated disinfection (PAD) methods against Enterococcus faecalis (E. faecalis) biofilms. MATERIALS AND METHODS: Sixty-five human mandibular premolars with straight root canals were selected. After root canal preparation, the samples were sterilized and placed into eppendorf tubes with 1 mL brain heart infusion broth containing 1.5×10(8) colony-forming units (CFUs)/mL of E. faecalis. The contaminated samples were then divided into four groups (n=15) according to the disinfection method used: Group 1, Saline (positive control); Group 2, NaOCl (negative control); Group 3, Gaseous O3; and Group 4, PAD. Three non-contaminated teeth were used to control the infection and sterilization process. The CFUs were counted and the data were analyzed statistically. RESULTS: There was a statistically significant difference between the experimental and control groups (P<0.05). The saline group had the highest number of remaining microorganisms. Complete sterilization was achieved in the 2.5% NaOCl group. There were no statistically differences between PAD and gaseous O3 (P>0.05). CONCLUSION: Both PAD and gaseous O3 have a significant antibacterial effect on infected root canals. However, 2.5% NaOCl was superior in terms of its antimicrobial abilities compared with the other disinfection procedures.

Impact of case volume on outcomes of ureteroscopy for ureteral stones: the clinical research office of the endourological society ureteroscopy global study.

BACKGROUND: The Clinical Research Office of the Endourological Society (CROES) undertook the Ureteroscopy Global Study to establish a prospective global database to examine the worldwide use of ureteroscopy (URS) and to determine factors affecting outcome. OBJECTIVE: To investigate the influence of case volume on the outcomes of URS for ureteral stones. DESIGN, SETTING, AND PARTICIPANTS: The URS Global Study collected prospective data on consecutive patients with urinary stones treated with URS at 114 centres worldwide for 1 yr. Centres were identified as low or high volume based on the median overall annual case volume. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Pre- and intraoperative characteristics, and postoperative outcomes in patients at low- and high-volume centres were compared. The relationships between case volume and stone-free rate (SFR), stone burden, complications, and hospital stay were explored using multivariate regression analysis. RESULTS AND LIMITATIONS: Across all centres, the median case volume was 67; 58 and 56 centres were designated as low volume and high volume, respectively. URS procedures at high-volume centres took significantly less time to conduct. Mean SFR was 91.9% and 86.3% at high- and low-volume centres, respectively (p<0.001); the adjusted probability of a stone-free outcome increased with increasing case volume (p<0.001). Patients treated at a high-volume centre were less likely to need retreatment, had shorter postoperative hospital stay, were less likely to be readmitted within 3 mo, and had fewer and less severe complications. At case volumes approximately >200, the probability of complications decreased with increasing case volume (p=0.02). The study is limited by the heterogeneity of participating centres and surgeons and the inclusion of patients treated by more than one approach. CONCLUSIONS: In the treatment of ureteral stones with URS, high-volume centres achieve better outcomes than low-volume centres. Several outcome measures for URS improve with an increase in case volume. PATIENT SUMMARY: Outcomes following treatment of ureteral stones by ureteroscopy (URS) were studied in a large group of patients at centres worldwide. The proportion of successful procedures (ie, those in which patients became stone free) increased as the annual volume of URS at a hospital increased. Hospital stays were shorter and postoperative complications were less likely at high-volume hospitals. We conclude that for URS, the best outcomes are seen in patients treated at high-volume hospitals.

The bond strength of endodontic sealers to root dentine exposed to different gutta-percha solvents.

AIM: To evaluate the effects of various gutta-percha solvents on the push-out bond strength of several root canal sealers on root dentine. METHODOLOGY: The root canals of 210 single-rooted human teeth were prepared with the ProTaper System (Dentsply Maillefer, Ballaigues, Switzerland) up to a master apical file size of F4, and the following variables evaluated for bond strength: solvent type (chloroform, eucalyptol and orange oil), time (2 and 5 min), sealer type (AH Plus, MTA Fillapex and Sealapex) and root thirds (coronal, middle and apical). After canal filling, three 1-mm-thick slices were obtained from each root sample, and the bond strength of the test materials was measured using a push-out test set-up at a cross-head speed of 1 mm min(-1) . The data were analysed using four-way factorial anova (P = 0.05). RESULTS: Bond strength was significantly affected by solvent type and time (P < 0.001). The use of chloroform for 5 min in the root canal decreased bond strength of all sealers (P < 0.001). Eucalyptol and orange oil did not affect the bond strength of the sealers (P > 0.05). In all conditions, the push-out bond strength was highest for AH Plus and lowest for MTA Fillapex (P < 0.001). Bond strength values decreased in a corono-apical direction in all groups (P < 0.001). CONCLUSIONS: Chloroform used for 5 min during retreatment decreased the bond strength of AH Plus, Sealapex and MTA Fillapex to root dentine.

Meta analysis of the treatment-related factors of external apical root resorption.

OBJECTIVE: To elucidate possible treatment-related etiological factors--such as, duration of treatment and apical displacement--for external root resorption. DESIGN: Meta-analysis of the available English-language literature. INCLUSION & EXCLUSION CRITERIA: Papers with a sample size > 10, fixed appliances, pre- and post-operative radiographs, and apical displacement recorded were included. History of trauma, prior root resorption and endodontic treatment were excluded. Appropriateness of these selections was tested with a 'funnel plot' analysis. OUTCOME MEASURE: Correlations between root resorption, apical displacement, and treatment duration. RESULTS: Mean apical root resorption was strongly correlated with total apical displacement (r = 0.822) and treatment duration (r = 0.852). CONCLUSION: The treatment-related causes of root resorption appear to be the total distance the apex had moved and the time it took.

Perceived long-term prognosis of teeth with orthodontically resorbed roots.

OBJECTIVES: To investigate the perceived significance of root resorption in the dental community. STUDY DESIGN AND SAMPLE: Mail out survey questionnaire accompanied by morphed images of 10-50% root resorption. General practitioners, periodontists, prosthodontists and orthodontists were the participants. OUTCOME MEASURES: Correlations between 'significant' and 'detrimental to the longevity of the tooth'. These assessments were conducted within specialty groups and among. Also measured was the source of knowledge upon which practitioner assessments were based. RESULTS AND CONCLUSIONS: General practitioners were the most concerned about root resorption. Although most practitioners feel 50% root resorption is significant and detrimental to the longevity of the tooth, extraction followed by prosthetic replacement was not an option. No agreement among practitioners when orthodontic treatment should be terminated; the general practitioners were conservative suggesting termination after 35% root loss. History of trauma, genetic disposition and root morphology are the most cited predisposing factors. Lengthy treatment time concerns general practitioners more than the orthodontists. With the exception of orthodontists, dentists believe excessive force is detrimental to the root, but no one is able to define what excessive force is. Overall, dental school curricula overstate the causes of root resorption. Generally, dental professionals seem to base their opinions on myths and are largely inconsistent in their assessments.

Is enalapril adequate for the prevention of renal tissue damage caused by unilateral ureteral obstruction and/or hyperoxaluria?

Unilateral ureteral obstruction (UUO) and hyperoxaluria (HOX) can lead to end-stage renal disease with tubulointerstitial fibrosis. We investigated the effects of enalapril (E), an ACE-inhibitor, on rat kidneys with either UUO or HOX. Sham-operated, UUO, HOX, UUO+HOX, UUO+E and HOX+E rats were killed 14 days after UUO and/or HOX was initiated. Rat kidney sections were histologically scored for tissue damage and monocyte/macrophage infiltration was demonstrated with ED1 antibody and measured by computer image analysis software. Serious glomerular and tubulointerstitial damage was found for UUO and HOX, consisting of glomerular basement membrane thickening, tubular dilatation/collapse, tubular basement membrane thickening and the infiltration of mononuclear leucocytes (mainly macrophages). For HOX, calcium oxalate crystals were visible. Neither the scored histological parameters nor monocyte/macrophage infiltration was significantly decreased when E-treated were compared with untreated groups. We conclude that E did not ameliorate the parameters scored in either UUO or HOX. This being contrary to findings by other research groups, we hypothesize that E may be effective only in short-term UUO/HOX, with transforming growth factor, TGF-beta1, formation becoming partly independent of Ang II in late-stage UUO/HOX, or other fibrogenic cytokines than TGF-beta1 becoming predominant.

A stochastic evaluation of the decision to specialize in orthodontics.

OBJECTIVE: The objective of this paper is to identify under different scenarios, and from a financial point of view, the conditions required to successfully switch from the general dentistry practice to orthodontics. STUDY DESIGN: A mail survey was used to collect the data from the practicing orthodontists. They estimated the income, at certain points, in the working life of an orthodontist. The general practitioner data were taken from the American Dental Association figures. Subsequently, a stochastic model was constructed. RESULTS AND CONCLUSION: Those who decide to buy an existing practice expect higher profits in the near future, and therefore the required minimum number of remaining years of practice is lower than for those deciding to start a new practice. For both scenarios, the 3-year residency will delay the profits compared with a 2-year residency. Thus, an increased number of remaining years of practice is required. There must be more than 10 working years left in the practitioner's life to make the switch profitable.

Treatment time, outcome, and patient satisfaction comparisons of Damon and conventional brackets.

Efficiency of treatment mechanics has been a major focus throughout the history of orthodontics. Self-ligating brackets were developed on the premise that elimination of ligature ties creates a friction-free environment and allows for better sliding mechanics. It is expected that the self-ligating bracket will reduce the treatment time. This study was designed to compare the effectiveness and efficiency of Damon self-ligating (SL) brackets to those brackets ligated with either steel ligatures or elastomeric 'O' rings. Not only treatment time and the number of appointments needed were addressed, but the quality of the treatment outcome was also assessed. American Board of Orthodontics (ABO) grading criteria for models and panoramic radiographs were employed. Additionally, a nine-question survey was sent to the 215-patients in this study (108 Damon, 107 conventionally-ligated) to elicit their perceptions of how their orthodontic treatment progressed and finished. The results showed that patients treated with Damon SL brackets had significantly lower treatment times, required significantly fewer appointments, and had significantly higher ABO scores than those treated with conventionally-ligated edgewise brackets. There were no significant differences in Damon or non-Damon ABO scores with respect to gender. Damon patients over the age of 21 had significantly higher ABO scores. Conversely, the non-Damon patients under the age of 21 had significantly higher ABO scores. For pre-treatment Angle classification, no significant differences were noted. Patient responses showed that Damon patients perceived their treatment time as being shorter than expected. It appears that faster orthodontic treatment can be better as measured by the ABO criteria.

Maxillary expansion: a meta analysis.

The utility of maxillary expansion has been equivocal for more than 100 years. The advent of meta-analysis and evidence-based learning has provided an opportunity to look objectively at this treatment modality. Medline was searched from 1978 to 1999 for all studies examining the stability of transverse expansion of the human maxilla using initial search terms of maxillary expansion and palatal expansion which were limited to those English language and human subjects. The more than 5000 articles were reduced to 12 based on the defined inclusion and exclusion criteria. The two investigators participating in the study were blinded, the studies' authors and origins blacked out and the evaluation coded and scored. A cumulative 'Meta evaluation score' was computed for each study. Six studies remained for the final analysis. The mean expansion after adjustment according to the principles of meta analysis was 6.00 mm with a standard deviation of 1.29 mm. Of the 6-mm average, 4.89 mm was retained while wearing retainers. Five of the papers provided retention data and post-retention data, but only three studies provided both retention and post-retention data. The average age of patients in these reports was 10.8 years. The 6-mm average expansion with retention in the short-term (<1 year) yielded a 4.71-mm residual expansion. Subsequently, this expansion during the short-term post-retention period was reduced to 3.88 mm. Finally, in the long-term post-retention study period only 2.4 mm of the residual expansion was reported to have remained. This 2.4 mm of expansion remaining after more than a year or more of post-retention period was no greater than what has been documented as normal growth. There is insufficient data to conclude that any useful expansion beyond that can be expected through normal growth was retained.

Free and total prostate-specific antigen levels in saliva and the comparison with serum levels in men.

OBJECTIVE: We investigated free and total prostate-specific antigen (PSA) levels and free/total (f/t) ratio in the fasting saliva and compared them with the serum levels in normal individuals, in patients with benign prostatic hyperplasia (BPH) and prostate cancer. Our aim was to determine free and total PSA and f/t ratio in saliva and to improve and simplify the differentiation between BPH and prostate cancer by using saliva as an alternative to serum. METHODS: Serum and fasting saliva concentrations of free and total PSA were measured in 35 men with BPH, 16 men with stage D prostate cancer, and 25 healthy men. Serum and fasting saliva samples were collected at the same time and were analyzed on the same day at our laboratory with microparticle enzyme immunoassay technology. RESULTS: For the total of 76 men, there was a significant correlation between free and total PSA levels in each sample (r = 0.97 for serum and r = 0.44 for saliva, p<0.001). Although there was a significant difference between three groups for serum-free and total PSA levels and serum f/t ratios, no significant difference was determined between groups for salivary free and total PSA levels and salivary f/t ratios. No correlations were found between patient age and salivary PSA levels. CONCLUSIONS: Fasting salivary free and total PSA levels are not effected by high serum levels of prostatic origin. Although there was a significant difference between mean serum and salivary levels of free and total PSA in each group, the f/t ratio of saliva was very close to the serum ratio of normal subjects. Determination of free and total PSA in saliva to improve and simplify the differentiation between prostate cancer and BPH is not suitable for use as alternative measurement of serum.

Regulation of IL-1-induced gingival collagenase gene expression by activator protein-1 (c-Fos/c-Jun).

Matrix metalloproteinase-1 is probably involved in the progression of periodontal disease. The aim of this study was to investigate whether IL-1beta stimulates the expression of the activator protein 1 (AP-1) transcription factor and, consequently, if the AP-1 transcription factor participates in the regulation of collagenase gene expression in human gingival fibroblast cells. In this study, we demonstrate that the concentration of the protein components of AP-1 transcription factor, c-Fos and c-Jun, is enhanced by IL-1beta both at mRNA and protein levels, utilizing Northern blot analysis, electrophoretic mobility gel shift assay and Western blot analysis. The IL-1beta stimulated the collagenase-CAT and AP-1-CAT activities in a dose dependent manner with respect to the amount of DNA used in transfections. Further, overexpression of c-Fos and c-Jun proteins revealed a dose-dependent transcriptional activation of the collagenase promoter. These findings, coupled with the existence of AP-1 consensus DNA binding sites on the collagenase gene promoter, show that regulation of collagenase gene expression by IL-1beta involves the transcription factor AP-1 in gingival fibroblasts.

Renal tubular apoptosis after complete ureteral obstruction in the presence of hyperoxaluria.

Hyperoxaluria is a well-known cause of renal stone disease and in vitro studies have shown that oxalate crystals have a stimulatory effect on apoptosis of renal tubular epithelial cells. Total and partial ureteral obstruction also have an accelerating effect on apoptosis of renal tubular epithelial cells. The aim of the present study was to investigate the apoptotic effect of unilateral ureteral obstruction in the presence of hyperoxaluria on the rat kidney. Twenty-eight male Wistar rats were divided into four groups, with seven rats in each. The groups were named G1 (control), G2 (hyperoxaluric), G3 (obstructive) and G4 (hyperoxaluric + obstructive). G2 and G4 rats were given 1% ethylene glycol (a precursor for oxalates) in their drinking water. G1 and G2 rats underwent sham operation, while left proximal ureteral ligation with a 5-zero silk suture was performed on G3 and G4 animals. The rats were sacrificed 2 weeks after the operation; left nephrectomy was then performed. We searched for the apoptotic cells by direct immuno-peroxidase detection of digoxigenin-labeled genomic DNA. The mean +/- SD values of the apoptotic cell count was 0.86+/-0.90 in G1 and 4.33+/-3.81 in G2. The values for G3 and G4 were 30.17+/-16.85 and 302.67+/-184.45, respectively. We found a statistically significant difference between all groups (P < 0.001). When compared with the control group (G1), the mean apoptotic cell count was fivefold that of G2 and 35- and 351-fold those of G3 and G4, respectively. Our study demonstrated that hyperoxaluria with complete ureteral obstruction induces an excessive level of apoptosis, which is responsible for renal damage, and that ureteral obstruction is a more important factor for apoptosis than hyperoxaluria. Considering these data, we also believe that research studies for medical preventive measures must be considered for patients with ureteral obstruction and/or hyperoxaluria.

Defining characteristics of financially successful orthodontists.

Financially successful personality profiles in most of the business world have been reported to be the choleric (powerful) and the melancholy (perfect) types. In 1996, Hughes proposed that the same relationship possibly exists in the profession of orthodontics. The purpose of this study was to explore whether a dominant personality profile exists for the most financially successful orthodontists. A questionnaire was used to gather information regarding the financial sophistication and the dominant personality profile of each participating orthodontist. One hundred twenty-six of the 300 surveys distributed to orthodontists were returned for a response rate of 42%. For every question, the null hypothesis of independence was tested with the chi-square test. The null hypothesis of independence was rejected for a P value of less than.05. The results revealed that no correlation exists between the financial sophistication of orthodontists and their personality profiles. However, over two thirds of the orthodontists had the choleric (powerful) and the melancholy (perfect) as dominant personality types. Interestingly, the questionnaire shed much light on factors that do contribute to financial success in orthodontics. Although statistical differences are lacking in these data, certain traits about successful practitioners could be identified. These orthodontists (1) allow their practices to grow if it will increase the net income, (2) view control of overhead as a key principle, (3) emphasize the competence of staff in determining the success of practice, and (4) believe in marketing. Implementation of these simple and common sense principles in some orthodontic practices might affect the business significantly.

Reasons that orthodontic faculty teach and consider leaving teaching.

To assess reasons why orthodontic faculty consider leaving academia, a pretested questionnaire was mailed to 200 full-time (FT) and 200 part-time (PT) faculty randomly selected from the United States and Canada. A total of 144 (72 percent) of FT and 120 (60 percent) PT responded. About 38 percent FT and 25 percent PT were currently considering leaving academia. The average age of each group was about fifty years. Although significant differences were found in fifteen factors affecting the decision to leave, three factors ranked as most important (means> or =3.4) for FTs: salary support, financial support of department, and control over work or destiny. The three factors most important (means>3. 1) for PTs were: challenge of private practice, family commitments, and personal. FT and PT were similar in the most important and least important factors influencing their initial reasons to teach and satisfaction in teaching. However, the reasons why FT considered leaving were work related, while the PT's reasons were more personal. With the current shortage of FT orthodontic faculty becoming imminently greater, it appears that work-related issues could be addressed directly by administration.

Patient and parent preferences for orthodontic practices.

This study was designed to identify who chooses an orthodontic office and what factors might induce the attraction. Patients and parents from the lists provided by suburban orthodontic offices were contacted. A mail-out survey instrument was used to gather the data. Results revealed that the reputation of the practitioner was most important along with the level of caring attitude the office projected. It was also important that the office is located near home, interestingly, the mother is the most significant decision-maker in the family in choosing an orthodontic office. Moreover, not the cost of treatment but the payment plan was the critical element in the decision process. The higher income families with three or less children were attracted to office characteristics such as excellence of the orthodontist, attention, and convenience. A marketing strategy based on these elements might provide the best return on the investment.