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.

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.

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.

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.

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.