Supragingival dental biofilm profile and biofilm control during orthodontic treatment with fixed orthodontic appliance: A randomized controlled trial.

OBJECTIVE: The effectiveness of supragingival dental biofilm control during orthodontic treatment and changes in the bacterial profile were analyzed. DESIGN: Sixty-four participants aged 12-22 years (57% female) were included in the study. Participants underwent orthodontic treatment with fixed appliances and were randomly assigned to one of the three groups, which during a period of one month: (I) used chlorhexidine digluconate (CHX), (II) used high concentration of fluoride (F) gel and (III) performed standard oral hygiene. The plaque and gingivitis index, pH of biofilm and white spot lesions (WSL) were assessed. Changes of the bacteria in the biofilm were analyzed by the quantitative polymerase chain reaction RESULTS: Increase in the plaque index, pH of biofilm, and WSL was observed during orthodontic treatment with standard oral hygiene. Large interindividual variability was present, and the effects of one-month use of fluorides and CHX on clinical parameters were not significant. Despite standard hygiene the abundance of studied biofilm bacteria increased - the most Streptoccocus mutans (14.2x) and S. salivarius (3.3x), moderate Veillonella parvula (3x) and the least S. sobrinus (2.3x) and Agregatibacter actinomycetemcomitans (1.9x). The use of CHX reduced S. sobrinus (2.2x) and A. actinomycetemcomitans (1.9x). Fluoride use reduced A. actinomycetemcomitans (1.3x) and S. sobrinus (1.2x). Fluorides better controlled S. mutans than CHX. CONCLUSION: Bacterial biomass in supragingival biofilm increased during treatment with metal orthodontic appliances, with greater increase in cariogenic bacteria than periopathogens. Fluoride controlled S. mutans, while CHX S. sobrinus and A. actinomycetemcomitans.

Influence of saliva on the results of global laboratory coagulation tests.

BACKGROUND: Oral wounds inevitably come into contact with saliva which can affect the time needed for bleeding to stop. The influence of saliva can be non-specific, related to dilution of blood, and/or mediated by salivary factors that affect haemostasis directly. The aim of this study was to assess if mixing blood with an individual's saliva would affect the rate of its coagulation measured by global coagulation tests, prothrombin time (PT) and activated partial thromboplastin time (APTT). METHODS: The study included 30 healthy non-smoking volunteers. Paired blood and unstimulated saliva samples were obtained from each participant and PT and APTT were determined in blood, blood + saliva and blood + water mixtures. Coagulation tests were performed using the mechanical clot detection method. RESULTS: PT was significantly longer in both blood + saliva and blood + water mixtures compared to blood alone. APTT was significantly longer only in blood + water mixture compared to blood. CONCLUSIONS: Similarly prolonged PT in both mixtures suggests that both saliva and water prolong coagulation evenly due to their non-specific effect of blood dilution. The finding that APTT was significantly prolonged only when blood was mixed with water could indicate presence of tissue factor in saliva, however, in a concentration too low to influence the results of PT.

Cytotoxicity and oxidative stress induced by nickel and titanium ions from dental alloys on cells of gastrointestinal tract.

The aim was to explore the biological effect of nickel (Ni) and titanium (Ti) ions released from dental alloys. NiTi alloy were exposed to 40 mL of artificial saliva (pH = 4.8, t = 37 °C). The dynamics of Ni and Ti ions release during corrosion were recorded on the 3th, 7th and 14th day. Biological effect of Ni and Ti ions released from alloy was explored on cell lines of human tongue CAL 27, liver Hep G2 and colon Caco-2. Neutral Red uptake assay for the estimation of cell viability/cytotoxicity and 2',7'-dichlorofluorescein diacetate fluorimetric assay for reactive oxygen species were used. Cells were exposed to the following concentration of corrosion products: 5.0×, 1.0×, 0.5 and 0.1× during the period of 24, 48 and 72 h. To check the effect of each metal separately, cells were exposed to nickel-chloride and titanium-dioxide of corresponding concentration. The release of Ni is higher than of Ti (15.1-30.4 µg/L for Ni and 9.0-17.3 µg/L for Ti, respectively) and 5× higher concentrations are needed to induce cytotoxic effect. Ni and Ti ions alone do not induce a major cytotoxic effect, but their combination does indicating their synergistic effect. Increase in concentration of Ni and Ti tends to increase cytotoxicity, Ti more than Ni. Cytotoxicity and induction of free radicals are in strong positive linear correlation. Ions released from NiTi alloy during 14 days do not induce significant cytotoxic effect and would not have a clinically important impact. Cytotoxic effect is largely the result of the induction of free radicals.

Satisfaction with facial profile aesthetics: are norms overrated?

This study aimed to explore to what extent adults perceive deviations from the norm of a balanced profile with normal occlusion as reducing satisfaction with facial appearance and having a psychosocial impact. This cross-sectional study included 225 Caucasian subjects (64% women) aged 18-42 years. Their facial profiles were analyzed photogrammetrically and they were classified into three categories: within, below, or above the standard range for the Croatian population with a normal occlusion. Psychosocial issues were assessed by self-reported satisfaction with facial appearance and domains from the Orthognathic Quality of Life Questionnaire: social aspects of dentofacial aesthetics (SA), facial aesthetics concern (FA), and awareness of dentofacial aesthetics (AW). Men with a concave profile were less satisfied with their faces than those with a flat or convex profile (P<0.05). A reduced upper lip height in men resulted in a lower level of satisfaction and increased FA score, when compared to men with a normal or increased upper lip height (P<0.05). In women, a reduced middle third of the face increased AW (P=0.045). Deviations from a well-balanced facial profile, as well as the morphology of the nose and lip, do not increase psychosocial issues to a great extent. The range of acceptable facial characteristics is evidently much broader than the norms.

Perception of facial profiles: influence of female sex hormones and personality traits.

OBJECTIVES: The observational study investigated whether women's perception of the facial profile is related to changes in sex hormones during the menstrual cycle and under the influence of personality traits. SETTING AND SAMPLE POPULATION: Participants were heterosexual Caucasian normally menstruating women not using oral contraceptives (N = 30, aged 20-44 years). MATERIAL AND METHODS: The profile attractiveness was assessed by grading of thirteen men's and women's Caucasian profile distortions by a visual analogue scale (0 = least to 100 = most attractive) in the non-ovulating phase and ovulating phase of the menstrual cycle. Male profiles were graded twice-in social and emotional contexts. Personality traits were assessed by Big Five Inventory. RESULTS: The most attractive male profiles in both phases and contexts were a straight profile or mild lip retrusion. According to cluster analysis, non-ovulating females distinguish skeletal from dentoalveolar alterations; however, maxillary retrognathism was considered to be closer to an attractive profile, which were resulting from dentoalveolar manipulations only. Ovulating females, when considering emotional relationship, exhibit lowest preference for males with convex profiles and extreme concave profile, while they consider males with slightly prominent chins due to maxillary retrognathism, mandibular prognathism or pronounced lip retrusion closer to the most attractive males. No clear patterns of influence of personality traits were detected. Moderate lip protrusion was the most attractive female profile in ovulating and straight profile in non-ovulating phase. CONCLUSION: The favorable profiles, on average, are the same regardless of the female hormonal status and personality traits.

Visual presentation of a medical physiology seminar modifies dental students' perception of its clinical significance.

INTRODUCTION: The primary objective of this study was to assess whether exposing dental students to visual stimuli related to dental profession during the medical physiology seminar could affect their perception of the clinical relevance of the topic. SUBJECTS AND METHODS: A self-administered questionnaire on attitudes towards medical physiology was conducted amongst 105 students of the School of Dental Medicine in Zagreb, Croatia, aged 19-24 years (80% females) following a seminar on respiratory system physiology. Power-point presentation accompanying the seminar for a total of 52 students (study group) was enriched with pictures related to dental practice in order to assess whether these pictures could make the topic appear more clinically relevant for a future dentist. RESULTS: The results of the survey indicated that dental students in the study group perceived the topic of the seminar as more important for them as future dentists when compared to the perception of the control group (P = 0.025). DISCUSSION AND CONCLUSION: The results of this survey encourage physiology lecturers to present medical physiology as clinically relevant for dental students whenever possible as this could increase students' interest in the subject and their motivation for learning. Such an approach could be particularly beneficial if there is a significant time gap between basic courses and involvement of students into clinical training for it could promote meaningful learning.

Forces that fracture teeth during extraction with mandibular premolar and maxillary incisor forceps.

Our aim was to measure the forces that fracture teeth during extraction based on the effectiveness of the extraction forceps, and to compare them with data collected about forces applied to extracted teeth that did not fracture. We studied 208 patients whose teeth fractured during both the standard and our new method of extraction: maxillary incisors (n=79) extracted with forceps 1 (maxillary incisor forceps), and both maxillary (n=95) and mandibular incisors (n=34) extracted with forceps 13 (mandibular premolar forceps). Forces needed to fracture were assessed with a specially-designed instrument for measuring pressure and rotation. Mean (SD) pressure at the fracture site was significantly higher in maxillary incisors extracted with forceps 1 (1.26 (0.26) bar) then in both maxillary and mandibular incisors extracted with forceps 13 (0.96 (0.19) and 0.98 (0.16), p<0.001). Pressure at dislocation and both left and right rotation showed similar patterns. Pressure correlated to root surfaces of teeth ranging from r=0.35-0.54 but the correlation coefficients did not differ significantly between the teeth-forceps groups. Pressure was higher in fractured than in extracted teeth, and this varied from 3%-48%. In conclusion, forces that break teeth during extractions are sometimes only slightly higher than the extraction forces, so caution is needed during extraction.

The unique contribution of elements of smile aesthetics to psychosocial well-being.

Pleasant smile aesthetics is an important contributory factor to psychosocial well-being. The aim of this study was to determine the psychosocial influence of smile aesthetics. The study was cross-sectional on a convenient sample that included patients, pupils, students and faculty staff. A total of 155 subjects (36% male) aged 12-39 (mean age 21, interquartile range 19-23) were included. Occlusal characteristics were recorded by the Index of Complexity, Outcome and Need, and smiling frontal view photographs were obtained. Fourteen variables were measured using photogrammetric analysis: smile width, visibility of buccal corridors, maximum teeth exposure, total gingival display, lip thickness, degree of occlusal cant and deviation from golden proportion of the teeth in maxillary intercanine sector. Psychometric instruments included the Psychosocial Impact of Dental Aesthetics Questionnaire and the Rosenberg Self-Esteem Scale. Statistical analysis comprised multiple linear regressions. Malocclusion severity is the most important predictor of psychosocial influence of smile aesthetics and self-esteem, the unique contribution of which accounts for a total of 4-27% of variability. Female gender is associated with higher psychological influence of dental aesthetics while male gender and older age with self-esteem. Malocclusions have higher psychosocial impact than parameters of mini- and micro-aesthetics of smile related to visibility of buccal corridors, amount of teeth exposure, gingival display, lip thickness, presence of occlusal cant and deviation from golden proportion of the teeth. It appears that people are not as focused on details of their smile as they are on distinctive malposition of teeth.

Attitudes towards e-learning amongst dental students at the universities in Croatia.

AIM: To develop and test the psychometric characteristics of a questionnaire that measures attitudes towards e-learning, as well as to study attitudes about e-learning and to identify variables related to those attitudes amongst dental students. SUBJECT AND METHODS: The study was conducted from November 2010 to December 2011 at all three Croatian dental schools. A questionnaire entitled 'Attitude Towards e-Learning' consisting of 12 questions about socio-demographic data and 22 statements about attitude towards e-learning was self-administered by 386 students. Factorial analysis and Cronbach's alpha were used to test the psychometric characteristics of the questionnaire. Multiple regression analysis was used to identify variables related to attitudes towards e-learning. RESULTS: Factorial analysis confirmed two factors: positive attitude and negative attitude, which interpret 58% of the total variance and had good internal consistency of α = 0.852 and 0.668, respectively. The average score of positive attitude was 42 ± 6, indicating a highly positive attitude towards e-learning. The average score of negative attitude was 27 ± 6, indicating minor negative attitude. Higher age and study year, usage of the Internet in education, more frequent usage of Facebook and more attendance of e-courses demonstrated a significant influence on positive attitude towards e-learning (R(2)  = 0.304; P < 0.001). Lower year of study and less frequent attendance of e-courses had a significant influence on negative attitude (R(2)  = 0.268; P < 0.001). CONCLUSIONS: Dental students have generally positive attitudes towards e-learning. Teachers should adopt strategies to change negative attitudes by introducing more e-learning courses in lower study years and should encourage students to use the Internet in their education and communication with teachers and colleagues.

Effect of L-arginine dietary supplementation on salivary urea concentration and pH in physically active individuals.

BACKGROUND: The aim of this study was to assess if the consumption of 3 g of a commercially available L-arginine dietary supplement causes a postabsorptive rise in urea concentration or pH of unstimulated saliva in a group of physically active individuals. METHODS: Salivary urea and pH were determined for 117 participants in a randomized double-blinded placebo-controlled study. Samples were collected by 'spitting' method in fasting conditions. One hour prior to their second visit, participants consumed three tablets of L-arginine or placebo. RESULTS: Urea concentration was significantly lower at second measurement for both the study and control group. The magnitude of the change was not significant between the groups. pH was higher for both groups at second measurement, but only significant for the study group. The magnitude of the change was significant between the groups. Participants who intermittently ingested protein dietary supplements and those with a Body Mass Index (BMI) higher than 25 had significantly higher basal urea concentration. CONCLUSIONS: The results of this study did not confirm the hypothesis. Further studies are needed to determine the effects of different doses of L-arginine supplements on the biochemical composition of saliva and the influence of their long-term consumption on the risk of developing dental diseases.

Salivary levels of TNF-α and IL-6 in patients with oral premalignant and malignant lesions.

The aim of this study was to determine the salivary concentrations of tumour necrosis factor α (TNF-α) and interleukin 6 (IL-6) in patients with premalignant and malignant lesions. The study involved 57 patients who were examined between 2008 and 2010 at the Department of Oral Medicine and Department of Oral and Maxillofacial Surgery of the Medical Faculty, University of Rijeka, Croatia. They were divided into three groups: 19 patients with oral premalignant lesions, 19 with oral squamous cell carcinoma and 19 healthy control volunteers. Whole saliva was collected and investigated for the presence of TNF-α and IL-6 by enzyme immunoassay at the Department of Dentistry and Maxillofacial Surgery, Medical Faculty, University of Graz, Austria. All groups had statistically significant differences in values of TNF-α and IL-6 (P < 0.001). The results suggest that these proinflammatory cytokines are elevated in the saliva of patients with oral squamous cell carcinoma and oral premalignant lesions as compared to controls, which may have diagnostic and/or prognostic significance.

Skeletal components of class III malocclusions and compensation mechanisms.

The aim of this retrospective study was to assess the skeletal characteristics of sagittal maxillary and mandibular discrepancies resulting in class III malocclusions and compensation mechanisms in one Caucasian European population (Croatian). The study sample included 107 patients (63 females and 44 males), aged between 11 and 18 years of age (mean age 14.6 +/- 2.2), with a class III malocclusion. Forty-three angular and linear measurements were assessed from the pre-treatment lateral cephalographs of each subject. anova, Tukey post hoc and t-test were used for statistical analysis. The most common differential skeletal type was mandibular prognathism with a normal maxilla (43%), followed by maxillary retrognathism with a normal mandibular position (19.6%), while the combination of maxillary retrognathism and mandibular prognathism was found to be rare (<5%). Subjects with maxillary retrognathia, appeared to also have a vertical facial pattern, suggesting a tendency towards vertical growth as a possible compensation mechanism. Those with mandibular prognathia tended to exhibit a horizontal facial growth pattern and typically included more pronounced dento-alveolar compensation, that is, proclination of maxillary and retroclination of mandibular incisors. There were no differences observed in gender, overjet or soft tissue profiles between different sagittal skeletal types. Dominant protrusive mandible in Croatians can be related to European Caucasian ancestry, where this entity is historically described as 'Habsburg jaw'.

The influence of war on the oral health of professional soldiers.

AIM: Professional soldiers, although trained to deal with specific conditions, are not immune to war stress induced behavioural changes, and since oral diseases are behaviour-related some changes in the oral cavity could be expected. PARTICIPANTS AND METHODS: The study was conducted on 640 professional soldiers in the Croatian Army, aged 19-49 years. The study group consisted of 336 soldiers in active service during the war in Croatia (1991-1997), while control group included 304 soldiers in peacetime service. Decayed, Missing and Filled Teeth Index (DMFT) and Community Periodontal Index (CPI) as well as questionnaires concerning dental behaviour and diet were employed. RESULTS: War group soldiers had significantly poorer oral health with DMFT being 14.4 in the war group and 13.1 in the controls, respectively (p < 0.001). The war group also showed a significantly higher number of periodontal pockets and excluded sextants, but lower numbers of healthy sextants (1.3 war group and 2.1 control; p < 0.001). Significant differences between the war and peacetime groups according to the number of dental visits, daily brushing frequency and diet were found. There was a tendency towards the deterioration of oral health with increase in time spent in battle fields. CONCLUSION: War conditions have a significant influence on the increased prevalence and severity of oral diseases for professional soldiers.

Degree of correlation between two periodontal indices in a rural Croatian population.

AIM: To compare the periodontal status of patients measured by two indices, the Community Periodontal Index (CPI) and the Loss of Attachment Index (LA). METHOD: The CPI and LA index scores were determined for a sample of 367 adult subjects (1,535 dentate sextants) aged 15-65 years from two rural areas in Croatia and analysed according to subject, sextant and jaw. RESULTS: Partial correlation between the CPI and LA indices was found. Cumulative for all age groups, sextants with a CPI code 0, 1 and 2 most often appeared with a LA 0-3mm. Shallow pocket sextants (4-5mm) in 64.04% also correlated with the loss of attachment values 4-5mm. In deep pocket sextants (6-8 mm), a deviation from expectations was found as they appeared more often with a LA 9-11 mm designation (46.24%), rather than with an LA 6-8mm (34.41%) score. Very similar results were found between distribution per sextant, person and jaw in CPI codes 2, 3, 4 and cumulatively. CONCLUSION: CPI itself is not sufficient for periodontal status assessment, especially for the 35-44 years of age, and even more so for the 65+ group, also for the CPI code 4 in all ages.