Root canal shaping is performed with nickel-titanium instruments rotary instruments. Torsional or fatigue overload of instrument results in its fracture, representing a complication during treatment. Recent studies demonstrate that reciprocating motion increase instrument longevity and reduce the probability of instrument fracture. However, the effect depends on rotation angles and rotational speed. The need for kinematics evaluation was expressed in recent papers but it was not performed due to technical difficulties. In our study we propose an innovative approach of reciprocating motion analysis. A high speed video camera with a frame rate of 1000 fps was use for recording of reciprocating motion, enabling accurate quantitative analysis of kinematics. We described a reciprocating cycle, containing four distinct phases and found a significant difference between actual and manufactures’ declared kinematics parameters. Accurate evaluation of kinematics parameters facilitates their optimization aiming to increase safety of clinical use.
F.01 Acquisition of new practical knowledge, information and skills
COBISS.SI-ID: 1286572Objective: To compare palatal dimensions in six-year-olds with unilateral cleft lip and palate (UCLP) treated by different protocols with those of non-cleft children. Design: Retrospective intercenter outcome study. Patients:Upper dental casts from 129 children with repaired UCLP and 30 controls were analyzed by the trigonometric method. Setting: Six European cleft centers. Main outcome measures: Sagittal, transverse and vertical dimensions of the palate were observed. Statistics: Palate variables were analyzed with descriptive methods and nonparametric tests. Regarding several various characteristics measured on a relatively small number of subjects, hierarchical, k-means clustering and principal component analysis were used. Results: Mean values of the observed dimensions for five cleft groups differedsignificantly from the control (p(.05). The group with one-stage closure of the cleft differed significantly from all other cleft groups in most variables (p(.05). Principal component analysis of all 159 cases identified three clusters with specific morphological characteristics of the palate. A similar number of treated children were classified into each cluster, while all children without clefts were classified in the same cluster. The percentage of treated children from a particular group that fit this cluster ranged from 0 to 70% and increased with age at palatal closure and number of primary surgical procedures. Conclusion: At six years, children with stepwise repair and hard palate closure after age two more frequently result in palatal dimensions of noncleft control than children with earlier palatal closure and one-stage cleft repair.
F.01 Acquisition of new practical knowledge, information and skills
COBISS.SI-ID: 28764633The aim of the study was to evaluate the prevalence of periodontal pathogens Aggregatibacter actinomycemecormitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsytia (Tf ) and Treponema denticola (Td) in subgingival plaque of type 1 diabetes patients with periodontal disease in correlation to metabolic control. The presence of five periodontal pathogens was detected by multiplex polymerase chain reaction (PCR) using a Micro-IDent test (Hain Lifescience, Nehren, Germany). Results: The results of 42 plaque samples showed that Tf was found in 48 % followed by Td in 31%, Pg in 26%, Pi in 9% and Aa in 7%. No periodontal pathogens were detected in pockets with a depth of 4 mm. In 50% of samples taken from pockets with a depth of 5 mm, in all samples taken from pockets with a depth of 6 mm and in the majority of samples taken from pockets with a depth of 7 mm or more at least 1 of five periodontal pathogens was detected. Tf and Td were the most frequent combination of periodontal pathogens found in the same sample. The serum level of HbA1c in 9 patients where Tf was detected (7.5±4%) was significantly higher (F-test, p=0.002) than in 12 patients where Tf was not detected (6.8±0.4%). Similarly the serum level of HbA1c was significantly higher (F-test, p=0.001) in 8 patients where Td was detected (7.5±1.8%) comparing to the 13 patients where Td was not detected (7.0±0.5%). No such correlation was found for Pg, Pi and Aa. We are concluding that Tf and Td are most frequently found in subgingival plaque samples of type 1 diabetic patients and that these findings correlate with poorer metabolic control of patients.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 30372057Introduction: Porphyromonas gingivalis induces nitric oxide (NO) production in various cells, systemic NO elevation being expected in chronic oral challenge. Methods: Groups of BALB/c mice were inoculated orally with either live P. gingivalis ATCC 33277 or sterile broth on days 0, 2 and 4, with or without later administration of the inducible nitric oxide synthase (iNOS) inhibitor 1400W. Plasma and tissues were harvested on day 42 for assays of tumor necrosis factor-α (TNF-α), nitrite and nitrate (NOx) and tissue NO, or histology and iNOS immunohistochemistry. Results: No signs of gingivitis were observed, but plasma NOx was significantly elevated (P = 0.028) as was TNF-α (P = 0.079) in P. gingivalis-inoculated animals compared with controls, NOx being reduced when 1400W was used. NO production in organs showed a similar trend, with significant elevation in liver (P = 0.017) and kidneys (P = 0.027), whereas concomitant treatment of inoculated animals with 1400W caused significant reductions in NO in aorta (P = 0.008) and kidneys (P = 0.046). Sham-inoculated 1400W-treated animals had significantly increased plasma NOx (P = 0.004) and liver NO (P = 0.04). NOx in plasma correlated significantly with NO production in lungs (0.35, P = 0.032) and kidneys (0.47, P = 0.003). Immunohistochemistry demonstrated iNOS activity in many tissues in all groups. Conclusion: Repeated oral administration of P. gingivalis induced systemic NO and NOx production in mice, probably by activating iNOS as suggested by the response to 1400W.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 3055482Background: Inflammation of periodontal tissues may contribute to different systemic diseases and conditions. Similarly, system ic diseases may influence periodontal tissues. The aim of our epidemiological study was to evaluate the prevalence of systemic diseases and use of medication in patients referred forperiodontal treatment. Material and methods: ln 252 randomly selected patients referred to the Department of Oral Medicine and Periodontology, Division of Stomatology, University Medical Centre Ljubljana, we evaluated theprevalence of systemic diseases and use of medication, and examined the correlation of these two parameters with the patients' periodontal treatment needs. Systemic diseases were c1assified according to the International Classification of Diseases, and drugs were classified according to the national Drug Register. Periodontal treatment needs were assessed using the Community Periodontallndex of Treatment Needs. Results: We found that 62 per cent of the patients referred for periodontal treatment suffered from one or more systemic diseases, and 25 per ce nt were using medication. Both the prevalence of systemic diseases and use of medication were higher in patients with advanced periodontal disease requiring complex periodontal surgical treatment. Conclusion: Since our population is ageing, the rates of system ic diseases and use of medication are expected to increase. Therefore it is essential for dentists (periodontists) to obtain a detailed medical history.
F.01 Acquisition of new practical knowledge, information and skills
COBISS.SI-ID: 28153305