Bone response to early orthodontic loading of endosseous implants.

This study evaluated the clinical, radiographic, and histologic responses of tissues surrounding implants loaded with a heavy force of 500g for 20 weeks after a 1-week healing period. Unilateral mandibular and maxillary alveolar ridges in the premolar areas of a male dog and the bilateral mandibular alveolar ridges of a female dog were chosen for implant placement. The control implants (1 in the maxilla, 3 in the mandible) were placed in these quadrants after a 12-week healing period following extraction. The test implants (1 in the maxilla, 3 in the mandible) were implanted in the same quadrants after a 4-month osseointegration period of the control implants. Abutments were attached to the control and test implants after a 1-week healing period for the test implants. Superelastic nickel-titanium coil springs, producing a force of 500g (≈5 N), were activated between control and test implants for 20 weeks. Light microscopic assessment revealed that all implants were well integrated with the bone. Histologic analysis showed no definitive differences between test and control implants in the corticalization of bone trabeculae. The mean bone-implant contact values of the control implants for compression and tension sides were 55.99% and 64.04%, respectively. In the test implants, the bone-implant contact value was 57.27% for the compression side and 62.96% for the tension side. Potential clinical applications of these radiologic and histologic results include the possibility of minimizing the healing duration, even for high orthodontic forces, and the possibility of postorthodontic use of these implants as abutments for supporting prosthetic reconstruction.

Osmotic pressure and vasculature of gingiva in experimental diabetes mellitus.

BACKGROUND: Alterations in tissue osmotic pressure (OP) and vasculature are considered to be the inevitable aspects of an inflammatory process that subsequently alter the fluid dynamics of the tissues involved. The aim of this study was to reveal a profile of OP and vascular changes in periodontally healthy gingival tissues and analyze the relationship between them in diabetes mellitus (DM) to evaluate the possible effects of DM on the fluid dynamics of the periodontium. METHODS: Experimental DM was created by intraperitoneal streptozotocin injection in 10 periodontally healthy rats. These rats were used as the test group, and 10 systemically and periodontally healthy rats served as the control group. Gingival tissue samples obtained from the groups were used for the test procedures. OP was measured in the supernatants of these samples by a semimicrodigital osmometer. Vasculature was assessed as the alterations in vascularization (vessel number [VN]) and vasodilatation (vessel diameter [VD]) by histomorphometric means. RESULTS: There was a gross increase in the OP level of the test group (172.7 +/- 59.7 mOsm/kg) compared to the control group (11.4 +/- 4.2 mOsm/kg; P <0.001). VN was found to be significantly larger in the test group (12.7 +/- 2.8) than in the control group (6.8 +/- 1.1; P <0.001). VD was found to be smaller in the test group (10.1 +/- 2.8 microm) than in the control group (15.5 +/- 2.4 microm), and this difference was statistically significant (P <0.001). A positive correlation between OP and VN (r = 0.77; P <0.001) and a negative correlation between OP and VD (r = 0.1; P >0.05) were observed in the test group. CONCLUSION: Our results reveal that the fluid dynamics of periodontal soft tissues may be affected by the diabetic conditions in this diabetic model because of the increased OP and VN during the pathogenesis of the disease.

Clinical outcomes of guided tissue regeneration with Atrisorb membrane in the treatment of intrabony defects: a 3-year follow-up study.

In this controlled clinical trial, initial and long-term treatment outcomes of guided tissue regeneration (GTR) were investigated for a synthetic absorbable membrane (Atrisorb) in intrabony defects. Eighteen defects in 16 patients received GTR with Atrisorb (test), with the membrane applied by an indirect method, and 15 defects in 15 patients were treated with open flap debridement (control). Probing pocket depth (PPD), gingival recession (GR), clinical attachment level (CAL), and linear alveolar bone level (ABL) were recorded at baseline and at 1 and 3 years following the treatment procedures and were assessed as the therapeutic outcome parameters. Both groups demonstrated significant PPD reduction and CAL and ABL gain after 1 year. Among these parameters, alterations in PPD and CAL were statistically significantly greater in the test group than the control group 1 year postsurgery. No significant changes were noted in the parameters of the first year between and within the study groups after 3 years. The results suggest that GTR performed with Atrisorb membrane via an indirect application method may provide favorable clinical outcomes for intrabony defects, and these outcomes may be maintained at least as well as open flap debridement over an extended period.

Vascular endothelial growth factor (VEGF) levels of gingiva and gingival crevicular fluid in diabetic and systemically healthy periodontitis patients.

It has been demonstrated that diabetes mellitus (DM) may have an inductive effect on the vascular endothelial growth factor (VEGF) levels of periodontium during periodontal disease. The aim of this study is to confirm this phenomenon, investigating whether it is also valid for diabetic periodontitis patients under good metabolic control. Sixteen type II DM patients, all with a glycosylated hemoglobin (HbA1c) value less than 7 (test), and 15 systemically healthy (control) chronic periodontitis patients were included in the study. The VEGF concentrations in the gingival supernatants and gingival crevicular fluid (GCF) samples of the study groups were measured by enzyme-linked immunosorbent assay. The data were analyzed by Student's t test in statistical means. The VEGF levels were significantly higher in the gingival supernatants of the test group (55.89 +/- 8.11 pg/ml) than that of the control group (24.81 +/- 2.04 pg/ml; p < 0.01). However, there was no statistically significant difference in the VEGF levels of GCF between the study groups (38.96 +/- 4.89 pg/ml in the test and 32.20 +/- 4.02 pg/ml in the control group; p > 0.05). Our study confirms that DM affects the VEGF levels of periodontal soft tissues in periodontal disease, and our results also suggest that this effect may not be influenced by the metabolic control of DM.

An assessment of oral self-care in the student population of a Turkish university.

OBJECTIVES: The aim of this study was to determine the oral health behavior of Turkish non-dental university students. STUDY DESIGN AND METHODS: A sample of 610 non-dental university students attending the University of Ondokuz Mayis in Samsun were randomly selected from the whole student population (n=12604) via the random number method. The students were asked to fill out a standardized self-completion questionnaire about daily frequency of toothbrushing, kind of toothbrush, frequency of toothbrush replacement, frequency of dental flossing, use of antibacterial rinse, or any other oral hygiene aid, receiving of oral hygiene instruction and frequency of oral check-up. The data were analysed using the SPSS version 12.0.1 statistical software package. RESULTS: Sixty-eight per cent of the students brushed their teeth two or more times per day. Two or more times a day toothbrushing was more common among females than males (P<0.001). Few subjects (3%) used dental floss daily. Forty per cent of students used only the toothpick as an interdental oral hygiene device. Thirty per cent of the students visited a dentist for preventive treatment at least once a year. There was no significant difference in regularity of visits to the dentist between females and males (P>0.05). CONCLUSION: This study indicated that self-preventive oral behaviour of the Turkish university student is at a lower level than in industrialized countries.

Reactive oxygen species scavenging activity during periodontal mucoperiosteal healing: an experimental study in dogs.

Excessive release of reactive oxygen species (ROS) in wounded tissue due to inflammation and ischaemia is a deleterious and destructive phenomenon for the healing process. Hence, scavenging of ROS is one of the essential steps in normal wound repair. In this study, we presented a profile of free radical scavenging enzyme (FRSE) activity of periodontal mucoperiosteal wounds in order to investigate ROS activity during periodontal wound healing. Mucoperiosteal periodontal flaps were elevated in the mandibular buccal region of seven dogs between the first premolar and first molar teeth, creating acute incisional wounds in the inner side of the flaps and they were replaced 30 min after elevation. Gingival samples taken from certain biopsy regions at baseline (before flap elevation), day 3, 12, 21 and 30 were processed for detection of active amounts of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). All enzyme activities had increased by more than 100% of their baseline levels by day 3. SOD activity decreased gradually from days 3 to 30 and reached a level lower than the baseline value. The increase in CAT activity continued until day 21, and decreased to a level higher than the baseline value by day 30. GPX also decreased from day 3, and reached a level less than its baseline value by day 30. Our results suggest that FRSEs may contribute to the detoxification of ROS during periodontal mucoperiosteal healing. This relationship may be utilized to facilitate soft tissue and/or flap management in periodontal or intra-oral treatments.