The aim of this study was to compare the effect of subgingival ultrasonic scaling followed by repeated (three times) antimicrobial photodynamic therapy (PDT), ultrasonic scaling alone (US), and scaling and root planing with hand instruments (SRP) for initial periodontal treatment. Twenty-seven non-smoking systemically healthy chronic periodontitis patients were included. Residual pockets )-4 mm deep and bleeding on probing were debrided either with SRP, US alone, or US followed by a single episode of PDT during supportive periodontal treatment. Probing pocket depth (PPD), bleeding on probing (BOP), and clinical attachment level (CAL) were monitored over 12 months. The presence of five periodontal pathogens in the pockets was determined by a commercially available micro-IDent test. Intergroup and intragroup statistical analysis was performed. All three treatments resulted in a significant clinical improvement. Additional application of PDT to US failed to result in further improvement in terms of PPD reduction and CAL gain. However, it resulted in a higher reduction of BOP at 3 and 12 months comparing to US alone or SRP (PDT from 25 to 13 and to 9 %, US from 23 to 16 and to 12 %, and SRP from 17 to 10 and to 9 %, respectively). PDT reduced the proportion of positive sites after 6 months for Treponema denticola (TD) significantly more effectively than US or SRP (p(0.0001). Additionally, PDT resulted in a greater reduction of Aggregatibacter actinomycetemcomitans (AA), Tannerella forsythia (TF), and TD in medium pockets (4-6 mm) (p(0.02) and of TD in deep pockets ()6 mm) compared to mechanical debridement alone (p(0.05).
COBISS.SI-ID: 31752665
Introduction: Type 2 diabetes is known to affect bone metabolism. In this study, we aimed to determine the effects of type 2 diabetes on bone remodeling during orthodontic tooth movement. Methods: The 48 rats were divided into 4 groups: Wistar control group (n = 8), Goto-Kakizaki (GK) control group (n = 8), Wistar appliance group (n = 16), and GK appliance group (n = 16). The distances between the teeth were measured weekly. On day 42, maxillary alveolar bone specimens were obtained for histologic evaluation and determination of the gene expression levels of the receptor activator of nuclear factor [kappa] B (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG). Results: No signi fi cant difference was observed in the levels of tooth movement between the 2 appliance groups. After orthodontic force application, the alveolar bone volume and osteoblast surface in the GK rats were diminished compared with those in the Wistar rats. The increase in the osteoclast surface relative to the control groups was 2.4-fold greater in the GK rats than in the Wistar rats. Significant upregulations of the RANK and OPG gene expression levels in the Wistar appliance group were observed. The RANKL/OPG ratio was increased in the GK appliance group compared with the Wistar appliance group. Conclusions: Diminished bone formation and slightly increased bone resorption were observed during orthodontic tooth movement in the rats with type 2 diabetes.
COBISS.SI-ID: 32544985
The study evaluated the micro push-out bondstrength of resin material (Multicore Flow) to two types offiber posts (FP), namely fiber-reinforced composite (FRC)Postec and Radix Fiber posts using Er:YAG laser pretreatment.FP were divided into four groups, two being controlgroups. Before the core build-up procedure, representativespecimens from each group were chosen to determine thesurface roughness (Ra) at three different areas using a contactprofilometer, while after the procedure, 1.5-mm-thick discswere sectioned and the micro push-out method was used toassess the bond strength of the core build-up material to thefiber post in each group. Two-way analysis of variance wasused for statistical analysis with the level of significance set atp(0.05. Scanning electron microscopy was used to analyzethe post surfaces after Er:YAG laser pretreatment and toclassify the failure mode after loading. The type of pretreatment(p(0.001) and an interaction between the pretreatmentand type of post (p(0.001) had a significant effect on the bondstrength, while the type of post did not (p=0.965). The meanbond strength in the Er:YAG laser pretreatment group wassignificantly lower compared to the FRC Postec posts controlgroup (p(0.001), while there was no significant differencebetween the Radix Fiber posts groups (p=0.680). Mean Ravalues from the Er:YAG laser pretreatment groups were significantlyhigher compared to control groups (p(0.001).Er:YAG laser pretreatment at tested parameters negativelyaffected the bond strength of Multicore to FP and cannot berecommended as a standard procedure.
COBISS.SI-ID: 1092012
The periodontopathogen Aggregatibacter actinomycetemcomitans synthesizes several virulence factors, including cytolethal distending toxin (CDT). The active CDT holoenzyme is an AB-type tripartite genotoxin that affects eukaryotic cells. Subunits CdtA and CdtC (B-components) allow binding and intracellular translocation of the active CdtB (A-component), which elicits nuclear DNA damage. Different strains of A. actinomycetemcomitans have diverse virulence genotypes, which results in varied pathogenic potential and disease progression. We have evaluated periodontitis-associated flora from larger group of our patients and identified an A. actinomycetemcomitans strain isolated from two patients with advance chronic periodontitis that has a regular cdtABC operon, which, however, codes for a unique, shorter, variant of the CdtB subunit. We describe the characteristics of this CdtBΔ116–188, which lacks the intact nuclear localisation signal and the catalytic histidine 160. We show that the A. actinomycetemcomitans DO15 isolate secretes CdtBΔ116–188, and that this subunit cannot form a holotoxin and is also not genotoxic if expressed ectopically in HeLa cells. Furthermore, the A. actinomycetemcomitans DO15 isolate is not toxic, nor does it induce cellular distention upon infection of co-cultivated HeLa cells. Biological significance of this deletion in the cdtB remains to be explained.
COBISS.SI-ID: 3944783
The study assessed bacterial microleakage of materials used for short and long term temporization in endodontics. One hundred and twenty-eight human upper third molars were divided into six experimental groups (n=20) and two control groups: negative (n=4) and positive (n=4). The standardized access cavities were prepared and filled with 1) Cavit, 2) Fuji II LC, 3) Fuji IX, 4) Voco Clip, 5) AdheSE&Tetric EvoCeram and 6) Excite&Tetric EvoCeram. After storage in saline for 24 hours the crown of each tooth was sectioned to obtain 5.5 mm high disks, which were assembled in a standard setup for bacterial microleakage studies using S. mutans. The monitoring lasted 90 days. Kaplan-Meier survival analysis was performed. The lowest amount of leaking samples was found in AdheSE&Tetric EvoCeram (31.3%), Cavit (33.3%) and Excite&Tetric EvoCeram groups (35.3%), followed by Fuji II LC (66.7%), Voco Clip (83.3%) and Fuji IX (88.2%) groups. According to the day of microleakage, materials could be classified in three groups with statistically significant differences (p(0.5). In the first group were Cavit (70 days), AdheSE&Tetric EvoCeram (68 days) and Excite&Tetric EvoCeram (65 days), in the second group were Voco Clip (44 days) and Fuji II LC (43 days), and in the third group was Fuji IX (21 days). None of the tested materials was able to completely prevent bacterial microleakage during the time of the study. Adhesively bonded composites and Cavit offer better sealing compared with glass ionomer cements, resin modified glass ionomer cements, and composites without the use of an adhesive system.
COBISS.SI-ID: 3103916