Global, Regional, and National Levels and Trends in Burden of Oral Conditions from 1990 to 2017: A Systematic Analysis for the Global Burden of Disease 2017 Study.

Government and nongovernmental organizations need national and global estimates on the descriptive epidemiology of common oral conditions for policy planning and evaluation. The aim of this component of the Global Burden of Disease study was to produce estimates on prevalence, incidence, and years lived with disability for oral conditions from 1990 to 2017 by sex, age, and countries. In addition, this study reports the global socioeconomic pattern in burden of oral conditions by the standard World Bank classification of economies as well as the Global Burden of Disease Socio-demographic Index. The findings show that oral conditions remain a substantial population health challenge. Globally, there were 3.5 billion cases (95% uncertainty interval [95% UI], 3.2 to 3.7 billion) of oral conditions, of which 2.3 billion (95% UI, 2.1 to 2.5 billion) had untreated caries in permanent teeth, 796 million (95% UI, 671 to 930 million) had severe periodontitis, 532 million (95% UI, 443 to 622 million) had untreated caries in deciduous teeth, 267 million (95% UI, 235 to 300 million) had total tooth loss, and 139 million (95% UI, 133 to 146 million) had other oral conditions in 2017. Several patterns emerged when the World Bank's classification of economies and the Socio-demographic Index were used as indicators of economic development. In general, more economically developed countries have the lowest burden of untreated dental caries and severe periodontitis and the highest burden of total tooth loss. The findings offer an opportunity for policy makers to identify successful oral health strategies and strengthen them; introduce and monitor different approaches where oral diseases are increasing; plan integration of oral health in the agenda for prevention of noncommunicable diseases; and estimate the cost of providing universal coverage for dental care.

The modulation of mature dendritic cells from patients with type 1 diabetes using human periodontal ligament stem cells. An in-vitro study.

OBJECTIVE: This in vitro study aimed to investigate whether human periodontal ligament stem cells isolated from impacted third molars can modify the maturation and phenotype of monocyte-derived dendritic cells pulsed with GAD-65 obtained from patients with type 1 diabetes. BACKGROUND: Human periodontal ligament stem cells (PDLSCs) have been found to display cell surface marker characteristics similar to bone marrow stromal stem cells (BMSSCs). The immunosuppressive effects on dendritic cells (DCs), T and B cells as well as their low immunogenicity allow the use of PDLSCs in stem cell therapies for autoimmune diseases including type 1 diabetes (T1D). Studies on the immunomodulatory potential of PDLSCs in the context type 1 diabetes are lacking but are therefore worth pursuing. METHODS: CD14 + monocytes isolated from peripheral blood mononuclear cells (PBMNCs) of type 1 diabetic patients were differentiated into immature Dendritic Cells (iDCs) and then maturation was induced to generate Mature Dendritic Cells (mDCs). The mDCs were pulsed with human recombinant GAD-65 and then co-cultured with PDLSCs that were isolated from impacted third molars and characterized. The changes in the levels of differentiation and maturation surface markers on the dendritic cells were analyzed by flow cytometry at the immature state, mature state and after the co-culture experiment. The levels of the secreted cytokines; IL-6, IL-10, and TGF-ß were measured by ELISA in cell-free culture supernatant. RESULTS: PDLSCs exerted an immunosuppressive effect on fully mature dendritic cells from patients with type 1 diabetes. This immunoregulatory property of was apparent by the reduction of all maturation markers including CD80, CD83, CD86, CD40, CD1a, CD209 and HLA-DR. Moreover, there was a detection of high levels of anti-inflammatory cytokines in the co-culture supernatant media including a significant increase in the concentration of IL-6 and TGF-ß. CONCLUSIONS: The current in vitro study provides strong evidence that PDLSCs seem to be a very promising source for overcoming the autoimmune destruction seen in T1D as they exerted an immunosuppressive effect on monocyte derived mDCs from patients with T1D. Additional studies should be conducted to further reveal the immunomodulatory and suppressive properties of PDLSCs and their potential use in immunotherapy for this disease.

Effectiveness of a tooth-brushing programme using the picture exchange communication system (PECS) on gingival health of children with autism spectrum disorders.

PURPOSE: The Picture Exchange Communication System (PECS) is a communication system for children with autism spectrum disorders (ASD). The aim of this study was to assess the effect of a PECS-based tooth-brushing programme on gingival health in children with ASD and assess parents' perception of PECS. METHODS: This was a prospective interventional study. Using PECS as a pictures/cards series showing a structured tooth-brushing method, 37 children with ASD (31 males, 6 females) (average age 9.49 ± 4.10, 4-16 years) and their parents/caregivers were trained on tooth-brushing twice, 2 weeks apart. Data collected after examinations (baseline, 3, 6-months) included gingival and plaque indices (GI, PI) and two questionnaires (baseline, 6-months) for demographic data and parents' perception of PECS including difficulty rating (easy, hard, very hard) and PECS usefulness. RESULTS: Most children with ASD had language abilities (64.9%) and prior PECS use (67.6%). Both GI and PI significantly dropped between baseline and both re-evaluations, (P < 0.001). Age, among studied factors, significantly affected PI only at all stages (P < 0.001). Most parents/caregivers (75.7%) rated PECS as hard, but useful (100%). Age and PECS prior use significantly affected PECS difficulty rating (P = 0.000 and 0.031, respectively), while sex did not (P > 0.05). CONCLUSION: PECS though rated as hard was useful in improving gingival health in children with ASD.

Effect of CPP-ACP on Streptococcus mutans in saliva of high caries-risk preschool children: a randomized clinical trial.

PURPOSE: The aim of this study was to assess the efficacy of CPP-ACP in reducing salivary S. mutans levels and compare its effect as a dentifrice to use of a fluoride dentifrice alone, or with the sequential use of a combination of both agents (fluoride, then CPP-ACP) in three groups of preschool children over a 6-month period. METHODS: This was a double-blinded clinical trial, the sample (n = 127, age 4.6 ± 0.47 years), with high caries risk, was randomized into three groups which applied different agents twice daily; fluoride toothpaste (500 ppm, n = 50), CPP-ACP (10% w/v, n = 38), and combination group (n = 39) applied fluoride, then CPP-ACP. S. mutans salivary levels were measured by GC Saliva-Check Mutans™. RESULTS: Within groups, a significant decrease in S. mutans-positive children (SMPC) occurred in fluoride and combination groups at 3-months, (P < 0.05), and in all groups at 6-months, (P < 0.05). The highest reduction in SMPC occurred in the CPP-ACP group, however, there were no significant differences in SMPC between groups at all study intervals, (P > 0.05). CONCLUSION: Although all agents were effective, CPP-ACP showed the highest reduction in SMPC over 6-months.

Risk factors of stillbirth in Yemen.

BACKGROUND: Yemen has the highest stillbirth rate among the Arab countries. However, the risk factors of this high rate are lacking. This study aimed to determine the maternal, newborn, and service related risk factors for stillbirths at the main maternity hospital in Sana'a city. METHODS: A case-control study was conducted in the main maternity hospital in Sana'a city, Yemen. Case and controls were selected prospectively during the study period. Cases were women who delivered stillbirths after 24 weeks of gestation. Risk factors data for mothers and their neonates were collected using face-to-face interview and data abstraction from medical records. RESULTS: The study included 101 women with stillbirths and 202 women with singleton live births. Mothers older than 35 years (Odds ratio (OR) = 4.9) and those with low level of education were significantly more likely to give stillbirths. Prolonged labor (OR = 5.8), mothers' anemia (OR = 2.1), less than 4 antenatal visits (OR = 5.1) and meconium stained amniotic fluid (OR = 11.5) were significantly associated with increased odds of stillbirth. Prematurity (OR = 27), umbilical complications (OR = 6.4), low birth weight (OR = 17.7), and congenital complications (OR = 40.6) were significantly associated with higher odds of stillbirths. CONCLUSIONS: This study identified many risk factors of stillbirth that are amenable to intervention. Encouraging women to deliver at health facilities, providing better management of obstetrical complications, proper antenatal care, and prompt referral services are essential for reduction of stillbirths in Yemen.

Association between periodontal disease and adverse pregnancy outcomes in a cohort of pregnant women in Jordan.

BACKGROUND: The relationship between periodontal disease (PD) and adverse pregnancy outcomes remain unclear. The authors' objective was to assess the risk of adverse pregnancy outcomes in Jordanian women with periodontal disease compared to those without. MATERIALS AND METHODS: Between April 2009 and June 2010, 277 pregnant women with no systemic diseases at gestational age < 20 weeks were enrolled in the study. Dental and oral health examination was performed at enrollment after demographic, medical, and obstetrical information were recorded. Pregnancy outcomes were obtained by phone contact and review of medical records. RESULTS: The incidence of periodontal disease in the pregnant women enrolled was 31%. Women with PD were at higher risk for developing preeclampsia (PE), preterm birth (PB), and low birth weight (LBW). The rate of PE in women with PD was 18.6% compared to 7.3% in the control group (p = 0.005) (OR = 2.7, 95% CI: 1.2, 6.0). The OR for PB was (4.4, 95% CI: 1.7, 11.7) and for LBW was (3.5, 95% CI: 1.6, 7.5). CONCLUSIONS: PD is associated with increased risk of PE, PB, and LBW in healthy Jordanian women.

Prevalence of hepatitis B and C infections and associated factors among blood donors in Aden City, Yemen.

This study determined the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV ) and associated risk factors among blood donors in Aden city, Yemen. A systematic sample of 469 male blood donors was selected from those attending the national blood bank service in Aden between June and October 2007. Data were collected by questionnaire and blood samples collected. Of the 469 participants, 24 (5.1%) were positive for HBsAg and 6 (1.3%) for anti-HCV. In multivariate analysis, history of: blood transfusion (OR = 22.8), dental treatment (OR = 3.6), cupping (OR = 3.9) and malaria infection (OR = 6.8) were significantly associated with being positive for HBsAg. Those with history of blood donation were less likely to be positive for HBsAg (OR = 0.17). Those with a history of blood donation were significantly less likely to be positive for anti-HCV positivity (OR = 0.05), while those with history of blood transfusion were more likely to test positive (OR = 65.6). The prevalence of HBV and HCV among blood donors in Yemen is still high compared to many other countries.

Health-related quality of life of adolescents with overweight or obesity in the north of Jordan.

BACKGROUND: Previous studies showed that overweight and obesity in children and adolescents are associated with impaired health-related quality of life (QOL). The objective of this study was to describe health-related QOL among Jordanian adolescents who were overweight or obese. METHODS: This is a cross-sectional study conducted among Jordanian students aged between 13 and 18 years in three educational directorates in Irbid City in the north of Jordan. Using simple random sampling, two male schools and two female schools were selected from the list of each directorate to represent all schools in north of Jordan. In each selected school, all adolescents aged 13-18 years were visited in their classes and were invited to participate in the study. Of the total number of 1561 subjects, 1433 (91.8%) agreed to participate in the study. The short-form 15-item Pediatric Quality of Life Inventory version 4.00 was used to measure health-related QOL among participants. Body mass index (BMI) was calculated and interpreted according to the BMI-for-age growth charts of the Center for Disease Control and Prevention guidelines. RESULTS: This study included 707 boys and 726 girls; 17.6% of participants were overweight and 7.8% were obese. For boys and girls, adolescents who were overweight or obese had significantly lower average scores for psychosocial health summary scale and physical functioning scale. Female gender, age of 16-18 years, fathers' education of high school or less and unemployed fathers (for social functioning and physical functioning) were significantly associated with decreased average scores of all scales and subscales of Pediatric Quality of Life Inventory. CONCLUSIONS: Compared with healthy adolescents, adolescents who were overweight or obese reported significantly lower health-related QOL in all domains. Girls reported greater effect of overweight and obesity on their health-related QOL.

Depression is associated with low levels of 25-hydroxyvitamin D among Jordanian adults: results from a national population survey.

Although low serum 25-hydroxyvitamin D (25(OH)D) and elevated serum parathyroid hormone (PTH) have been associated with depression in clinical settings, this link in community-dwelling individuals is inconclusive. The present study aimed at examining the association between serum 25(OH)D and PTH levels and the presence of depression in a national population-based household sample of 4,002 Jordanian participants aged ≥25 years. The DASS21 depression scale was used to screen for depression, and serum concentrations of 25(OH)D and PTH were measured by radioimmunoassay. Multiple logistic regression models were used to explore the association between serum 25(OH)D and PTH levels and depression. The unadjusted odds ratio (OR) decreased linearly with increasing quartiles of serum 25(OH)D (P(trend) = 0.00). The OR for having depression was significantly higher among individuals in the first and second quartiles (OR = 1.4, 1.23, respectively) than among those in the fourth quartile (P values = 0.00 and 0.03, respectively). This relationship remained significant after adjusting for age, sex, marital status, education, BMI, serum creatinine, number of chronic diseases (OR = 1.39 and 1.21 and P values = 0.00 and 0.05, respectively) and after further adjustment for exercise, altitude, and smoking (OR = 1.48 and 1.24, respectively, and P values = 0.00 and 0.03, respectively). No significant association was found between serum PTH levels and depression. The decrease in risk of depression among participants started to be significant with serum 25(OH) D levels higher than 42.3 ng/ml (lower limit of the range of the third quartile). This value may help pinpoint the desirable level of serum 25(OH)D to be attained to help aid the prevention and treatment of depression.

The association between inflammatory bowel disease and periodontitis among Jordanians: a case-control study.

BACKGROUND AND OBJECTIVE: Inflammatory bowel disease (IBD) is hypothesized to involve immuno-inflammatory alterations, and the condition has been related to increased susceptibility to oral challenges. The objective of the study was to determine the association between the prevalence, severity and extent of periodontitis and both ulcerative colitis (UC) and Crohn's disease (CD). MATERIAL AND METHODS: A case-control study was conducted among patients who attended outpatient clinics at King Hussein Medical City in Jordan during the study period. All participants completed the questionnaire and underwent thorough oral and periodontal examinations. Periodontitis was defined as presence of four or more teeth with one or more sites with probing pocket depth ≥ 4 mm and clinical attachment level ≥ 3 mm. The general linear model multivariate procedure and multivariate binary logistic regression were used to analyse the data. RESULTS: This case-control study included 260 Jordanian adults (101 with UC, 59 with CD and 100 with no IBD) with a mean (SD) age of 39.4 (0.7) years. The prevalence of periodontitis was much higher among patients with CD and those with UC compared with subjects having no IBD in the age groups < 36 and 36-45 years old only. After adjusting for age and number of missing teeth, patients with CD (odds ratio 4.9, 95% confidence interval 1.8-13.2) and patients with UC (odds ratio 7.00, 95% confidence interval 2.8-17.5) had significantly higher odds of periodontitis than subjects with no IBD. In multivariate analysis, the severity of periodontitis was significantly higher among patients with CD and patients with UC when compared with subjects having no IBD. Ulcerative colitis patients but not CD patients had significantly higher prevalence of deep ulcers in oral soft tissues than the non-IBD group (p = 0.004). CONCLUSION: Patients with IBD have higher prevalence, severity and extent of periodontitis compared with those having no IBD.

Prevalence of hepatitis B and C infections and associated factors among blood donors in Aden city, Yemen

This study determined the prevalence of hepatitis B virus [HBV] and hepatitis C virus [HCV] and associated risk factors among blood donors in Aden city, Yemen. A systematic sample of 469 male blood donors was selected from those attending the national blood bank service in Aden between June and October 2007. Data were collected by questionnaire and blood samples collected. Of the 469 participants, 24 [5.1%] were positive for HBsAg and 6 [1.3%] for anti-HCV. In multivariate analysis, history of: blood transfusion [OR = 22.8], dental treatment [OR = 3.6], cupping [OR = 3.9] and malaria infection [OR = 6.8] were significantly associated with being positive for HBsAg. Those with history of blood donation were less likely to be positive for HBsAg [OR = 0.17]. Those with a history of blood donation were significantly less likely to be positive for anti-HCV positivity [OR= 0.05], while those with history of blood transfusion were more likely to test positive [OR = 65.6]. The prevalence of HBV and HCV among blood donors in Yemen is still high compared to many other countries

Hypertension prevalence, awareness, treatment and control, and associated factors: results from a national survey, jordan.

The study examined prevalence, awareness, treatment and control of hypertension (HTN), and associated factors and to evaluate the trend in hypertension between 2009 (period 2) and 1994-1998 (period 1). A national sample of 4117 adults aged 25 years and older was selected. Prevalence rate of HTN (SBP ≥ 140 or DBP ≥ 90 or on antihypertensive therapy) was 32.3% and was higher than the 29.4% prevalence rate reported in period 1. Prevalence rate was significantly higher among males, older age groups, least educated, obese, and diabetics than their counterparts. The rate of awareness among hypertensives was 56.1% and was higher than the 38.8% rate reported form period 1 data. Awareness was positively associated with age, smoking, and diabetes for both men and women, and with level of education and body mass index for men. Rate of treatment for HTN among aware patients was 63.3% and was significantly higher than the 52.8% rate reported in period1. Control rate of HTN among treated hypertensives was 39.6%; significantly higher than the 27.9% control rate in period 1. Control of HTN was positively associated with age but only for women. In conclusion, HTN is still on the rise in Jordan, and levels of awareness and control are below the optimal levels.

Reasons for cancellation of elective operations at a major teaching referral hospital in Jordan.

Cancellation of elective scheduled operations leads to an inefficient use of operating room time and a waste of resources. This prospective records-based study aimed to determine the rate of and reasons for cancellations of scheduled elective surgical operations in a major teaching referral hospital in Jordan. Over a period of 12 months, cancellation was recorded in 382 (3.6%) of 10 485 scheduled elective surgical operations. Day unit cancellations accounted for 27.5% and inpatient cancellations for 72.5%. Patient-related reasons, administrative and medical reasons accounted for 31.4%, 30.4% and 38.2% of all cancelled operations respectively. The most common patient-related reason for cancellation was patient non-attendance. The most common administrative reason for cancellations was unavailability of hospital admission beds. Although the cancellation rate was low in comparison with the reported rates worldwide, reductions might be achieved by adopting some important interventions, especially better bed utilization.

The association between periodontal disease, physical activity and healthy diet among adults in Jordan.

BACKGROUND AND OBJECTIVE: Physical inactivity and an unhealthy diet have been implicated as risk factors for several chronic diseases that are known to be associated with periodontitis, such as cardiovascular diseases, obesity and diabetes. Studies investigating the relationship between periodontitis and physical activity and diet are limited. Therefore, this study was conducted to determine the relationship between physical activity, healthy eating habits and periodontal health status. MATERIAL AND METHODS: A systematic random sample of 340 persons, 18-70 years of age, was selected from persons accompanying their relative patients who attended the outpatient clinics in the medical center of Jordan University of Science and Technology in north of Jordan. Data collected included socio-demographic and clinical characteristics, anthropometric measurements, physical activity level and dietary assessment. RESULTS: Individuals who were highly physically active had a significantly lower average plaque index, average gingival index, average clinical attachment loss (CAL) and percentage of sites with CAL ≥ 3 mm compared to individuals with a low level of physical activity and individuals with a moderate level of physical activity. Those who had a poor diet had a significantly higher average number of missing teeth and an average CAL compared with those who had a good diet. In the multivariate analysis, a low level of physical activity and a poor diet (diets with a healthy eating index score of < 50 points) were significantly associated with increased odds of periodontitis. CONCLUSIONS: A low physical activity level and a poor diet were significantly associated with increased odds of periodontal disease. Further studies are needed to understand this relationship in greater detail.

Prophylactic use of aspirin does not induce anaemia among adults.

BACKGROUND: Aspirin is considered one of the most prescribed drugs worldwide, predominantly for its cardioprotective effects. However, its use may be precluded by gastrointestinal and haematological side-effects. OBJECTIVE: To investigate the association between the prophylactic use of aspirin and the prevalence of anaemia among adults. Other demographic factors and co-morbid conditions such as kidney or liver failure, diabetes mellitus, hypertension, hyperlipidemia, coronary artery disease, ulcer, ulcer medications, and the use of non-steroidal anti-inflammatory drugs, which might be associated with anaemia, were also investigated. RESULTS: No association between aspirin use and prevalence of anaemia was observed. Age and smoking were the only factors contributing significantly to the occurrence of anaemia. Moreover, gender, age and the use of peptic ulcer medication were associated with reduced haemoglobin levels. CONCLUSION: The results may help in minimizing concerns about the development of anaemia among patients on aspirin. They highlight the importance of age, gender, smoking and ulcer medication in determining the incidence of anaemia among those patients.

The effect of full-mouth tooth extraction on glycemic control among patients with type 2 diabetes requiring extraction of all remaining teeth: a randomized clinical trial.

BACKGROUND AND OBJECTIVE: Several studies have shown that periodontitis can complicate the severity of diabetes by worsening the degree of glycemic control. The purpose of this study was to determine the effect of full-mouth tooth extraction on glycemic control among type 2 diabetic patients. MATERIAL AND METHODS: A total of 58 patients with type 2 diabetes mellitus and advanced periodontitis who were requiring extraction of all remaining teeth were randomized consecutively into treatment (full-mouth tooth extraction) and control groups (no treatment). Eight patients were lost to follow-up or reported use of antibiotics, leaving 50 patients to be included in the analysis. All patients had all their remaining teeth in a hopeless condition. Relevant data were collected, and glycosylated hemoglobin (HbA(1c) ) and fasting blood glucose levels were measured at baseline and at follow-up times of 3 and 6 mo. RESULTS: At baseline, the mean (SD) HbA(1c) level was 8.6% (1.24) in the treatment group and 7.7% (0.87) in the control group. In the treatment group, the mean HbA(1c) level decreased significantly from 8.6% at baseline to 7.4% after 3 mo of denture treatment, and continued to decrease to 7.3% after 6 mo. In the control group, the mean HbA(1c) decreased from 7.7% at baseline to 7.5% after 3 mo, and remained almost the same after 6 mo. After adjusting for the baseline HbA(1c) , the mean reduction in HbA(1c) after 3 mo in the treatment group [1.23% (0.79)] was significantly higher than the mean reduction in the control group [0.28% (0.87)]. CONCLUSION: Full-mouth tooth extraction resulted in an improvement in glycemic control among diabetic patients. Large-scale multicentre clinical trials are needed to confirm the current evidence.

Dentist-assistant interaction styles in Jordan.

OBJECTIVES: To assess dentist-assistant interaction and communication styles and their associated factors in Jordan. METHODS: Three different areas in Amman where private dental clinics heavily cluster were chosen. The researcher visited all dental clinics in these areas and invited dentists to participate in this study. A structured self-administered questionnaire was designed and included the 22 items on staff communication that were used by Gorter and Freeman to assess communication styles. The culturally adapted items were analysed in such a way to reflect the structure that is used in the original study. RESULTS: There was a significant interaction between dentist's gender and communication styles (F = 3.8, P = 0.022). The only significant difference between men and women was for professional leadership style (P = 0.011) where men were more likely to adopt professional leadership style than women. For men, the average score for friendly leadership style was significantly lower than that for other styles. For women, the average score was the highest for gender interacting style which was significantly higher than that for friendly leadership style and professional interacting style, but not business leadership style. CONCLUSIONS: Communication and interaction styles between Jordanian dentists and their assistants differ according to gender. Jordanian dentists are less likely to adopt friendly leadership communication style compared with other styles.

Periodontal status of type 2 diabetics compared with nondiabetics in north Jordan.

The periodontal status of 106 type 2 diabetic patients was assessed and compared with that of 106 age-matched nondiabetics. Patients older than 20 years with type 2 diabetes mellitus were recruited from the outpatient internal medicine clinics at the 2 main hospitals in Irbid governorate, Jordan. Periodontal disease was more severe in type 2 diabetic patients than in nondiabetics, as indicated by significantly mean higher gingival index, periodontal pocket depth, clinical attachment level and tooth mobility. There was no significant difference in the mean plaque index between diabetics and nondiabetics. The severity of periodontal disease was significantly higher in patients with diabetes > 5 years than those with duration < 5 years.

Legionella pneumophila contamination of a dental unit water line system in a dental teaching centre.

OBJECTIVE: This study aimed to evaluate the extent of Legionella pneumophila contamination in a dental unit water line (DUWL) at a Dental Teaching Centre in Jordan. METHODS: Ten dental units were sampled from each teaching clinic, namely conservative dentistry, periodontology and prosthodontics. Samples were collected from the air/water syringe, high-speed hand piece and water cup filler. Sampling time was at the beginning of the working day (before the dental unit was used), after 2 min of flushing, and at midday. RESULTS: Legionella pneumophila counts ranged between 0 and 8.35 x 10(3) (CFU ml(-1)). Legionella pneumophila was detected in 86.7% of the dental units at the beginning of the working day, 40% after 2 min flushing and 53.3% at midday. The highest L. pneumophila counts were found at the beginning of the working day which were reduced by flushing the waterlines. The conservative dentistry clinic had the highest contamination level followed by the periodontology and prosthodontics clinics (P < 0.05). The rate of contamination can be ascribed to the dental procedures performed in the clinics, the degree of using the hand pieces, and water softening and heating. CONCLUSIONS: The difficulty of completely eliminating micro-organism contaminating water used for dental treatment and the resulting biofilm suggest that flushing of DUWL can be a first solution in reducing L. pneumophila counts, while the incorporation of a disinfection method is highly recommended. Water heating and softening should be considered in practicing dentistry as factors that may aid in L. pneumophila proliferation inside the DUWL.

Smoking habits among university students in Jordan: prevalence and associated factors.

Questionnaires were completed by 712 university students in north Jordan to estimate their prevalence of smoking. The reported prevalence of current smoking was 35.0% (56.9% for males and 11.4% for females). About 80% were cigarettes smokers. The majority (86.3%) of smokers smoked daily. Male sex, higher income, lower academic attainment and higher number of friends or family members who smoke were associated with increased prevalence of smoking. Those in the faculty of religion and law were less likely to smoke compared to those in other faculties. The results suggest that policy-makers need to initiate antismoking programmes in Jordanian universities.