Effect of ED-71, a New Active Vitamin D Analog, on Bone Formation in an Orthopedically Expanded Suture in Rats. A Histomorphometric Study

Objectives: The aim of this experimental study was to evaluate the effects of ED-71, a new active vitamin D analog, on bone regeneration in response to expansion of the mid-palatal suture, in rats, histomorphometrically.

Methods: Sixteen male 50-60 days old Wistar rats were separated into two equal groups (control and experimental). Both groups were subjected to expansion, and 30 grams of force was applied to the maxillary incisors with a helical-spring. Experimental group was treated with single-dose ED-71 (0.8 μg/kg body weight) in the mid-palatal suture locally and eight control animals received vehicle solution. Bone regeneration in the mid-palatal suture was evaluated by bone histomorphometric method and mineralized area (Md.Ar), fibrosis area (Fb.Ar), mineralized area/fibrosis area (Md.Ar/ Fb.Ar), bone area (B.Ar) and osteoblast number (N.Ob) parameters were evaluated. Mann Whitney-U test was used for statistical evaluation at P<.05 level.

Results: Statistical analysis showed significant differences between groups for all investigated histomorphometric parameters. Md.Ar (P<.001), Md.Ar/Fb.Ar (P<.001), B.Ar (P<.01) and N.Ob (P<.001) parameters were significantly increased and Fb.Ar (P<.001) measurement was significantly decreased in experimental group. ED-71 group with a mean of 24.55±6.47 showed statistically higher N.Ob than the control group (mean N.Ob: 12.82±5.81).

Conclusions: ED-71 has positive effects on early phase of bone regeneration in the mid-palatal suture in response to expansion and may be beneficial in routine maxillary expansion procedures. (Eur J Dent 2009;3:165-172)

Antibiofilm efficacies of cold plasma and er: YAG laser on Staphylococcus aureus biofilm on titanium for nonsurgical treatment of peri-implantitis

Objectives

The aim of the present study was to compare antibiofilm efficacies of the laser in contact and noncontact application modes and cold atmospheric plasma (CAP) on Staphylococcus aureus biofilm grown on sandblasted, large grit, acid-etched (SLA) titanium discs as an in vitro model of biofilm eradication on dental implant materials.

Methods

S. aureus biofilm was matured on titanium discs for 7 days then, treated with contact and noncontact Er:YAG laser and CAP. Antibiofilm efficacy of laser and plasma treatments were evaluated with colony counting and safranin assays. Surface characteristics of titanium disc were analyzed with scanning electron microscopy and surface roughness measurements. Temperature distribution over titanium discs were presented for the thermal safety assessment of laser and plasma treatments.

Results

: CAP resulted in 6-log inactivation of S. aureus biofilm, whereas biofilm inactivation was determined as 1 and 2.7-log for noncontact and contact laser treatments, respectively. Laser and plasma treatments did not cause any alterations on the roughness of titanium discs. Contact laser treatment caused a focal temperature increase up to 58°C, whereas plasma treatment led a uniform temperature distribution on the disc within safe limits.

Conclusion

CAP showed superior antibiofilm activity on 7-day-old S. aureus biofilm grown over SLA titanium discs, compared to contact and noncontact laser treatment without temperature increase and any damage to the surface of titanium discs.

Biological response of commercially available different tricalcium silicate-based cements and pozzolan cement

This study evaluated four root repair materials for cytotoxicity and cell attachment in vitro. Cell viability was determined at 24 hr, 3 days and 7 days by using a 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay with material extracts. Cell adhesion was examined with a scanning electron microscope on the surface of materials at 24 and 48 hr. Angelus MTA displayed the lowest cell viabilities at all-day incubations. Endocem had high biocompatibility on the first day. After culturing for 3 days and 7 days, the cell viabilities of Biodentine, Endocem and MM-MTA had similar results, and their cell viability was significantly higher than that of Angelus. No definite relation was found between the incubation time and the relative cell viability in any group. In scanning electron micrographs, the cells were attached to the material surface for all materials, although the cells in the Biodentine group were attached better than the other groups on the second day. Cell viability and cell attachment was lower in the Angelus group. Endocem, Biodentine and MM-MTA were similar in biocompatibility and cytotoxicity.

Nuclear factor-kappa B ligand and osteoprotegerin levels in serum and gingival crevicular fluid in patients with bone metastases treated with zoledronic acid

Bone metastases are frequently observed in patients with certain types of cancer and are significant cause of morbidity. Zoledronic acid (ZA) is routinely prescribed for patients with bone metastases by affecting osteoclast function. We aimed to assess the effect of ZA over time in patients with bone metastases by analyzing novel bone turnover marker levels including receptor activator of nuclear factor-k B ligand (RANKL) and osteoprotegerin (OPG) in serum and gingival crevicular fluid (GCF). Also, associations between these bone turnover markers with hematological and biochemistry dysregulation were studied. The study enrolled patients with bone metastases including 32 patients diagnosed with solid tumors and 15 patients with multiple myeloma. In these patients, GCF and serum RANKL and OPG levels were measured and compared with measures of hematological and biochemical parameters before and after 3 months of ZA therapy. Mean subject age was 54 years old with a range of 28-80 years. Skeletal-related events were observed in 8.5% of all patients. After the 3-month treatment of ZA therapy, no significant differences were found in serum and GCF levels of RANKL and OPG when compared with before treatment levels. GCF RANKL levels at baseline and following 3 months of ZA therapy were significantly higher in patients with solid tumors when compared patients diagnosed with multiple myeloma (p=0.001; p<0.001, respectively). GCF OPG levels after the entire course of ZA therapy were greater in patients with 5 or more bone metastases (p=0.04). For patients with multiple myeloma, control GCF OPG was negatively correlated with control platelet and WBC counts (p=0.018 and p=0.027, respectively). A negative correlation was observed between control serum RANKL and control serum OPG levels in myeloma patients (p=0.001). After 3 months of ZA therapy, no significant differences were observed in GCF and serum RANKL and OPG levels when compared with baseline. A negative correlation was observed between serum control RANKL and OPG levels in myeloma patients. OPG levels were greater in patients with 5 or more bone metastases. In patients diagnosed with multiple myeloma, GCF OPG levels were negatively associated with WBC and platelet counts.

OPG and RANKL levels around miniscrew implants during orthodontic tooth movement

INTRODUCTION

The aim of this study was to determine the peri-miniscrew implant crevicular fluid receptor activator of nuclear factor-кB ligand (RANKL) and osteoprotegerin (OPG) levels around loaded and unloaded miniscrew implants at different time intervals.

METHODS

Twenty loaded and 16 unloaded miniscrew implants were included in this study. All miniscrew implants were placed bilaterally between the maxillary second premolars and first molars as anchorage units for canine distalization. Peri-miniscrew implant crevicular fluid was taken from the mesiobuccal aspects of the loaded and unloaded miniscrew implants before loading; at 24, 48, and 168 hours; and on day 30 after force application. Enzyme-linked immunosorbent assay kits were used to determine RANKL and OPG levels in the peri-miniscrew implant crevicular fluid samples. Wilcoxon, Mann-Whitney U, and Spearman correlation tests were used for statistical evaluations at the P <0.05 level.

RESULTS

Although the total amount of OPG was not different between the groups, the total amount of RANKL was significantly elevated in the loaded miniscrew implant group (P <0.05) at all time periods. Peri-miniscrew implant crevicular fluid volume was the highest at 48 hours in the loaded group. Also, the OPG/RANKL ratio in the peri-miniscrew implant crevicular fluid was significantly decreased in the loaded miniscrew implant group.

CONCLUSIONS

The OPG and RANKL levels vary around loaded and unloaded miniscrew implants as a result of force application.

Dehiscence and fenestration in patients with different vertical growth patterns assessed with cone-beam computed tomography

OBJECTIVE

To test the null hypothesis that the presence of alveolar defects (dehiscence and fenestration) was not different among patients with different vertical growth patterns.

MATERIALS AND METHODS

A total of 1872 teeth in 26 hyper-divergent (mean age: 24.4 ± 4.8 years), 27 hypo-divergent (mean age: 25.1 ± 4.5 years), and 25 normo-divergent (mean age: 23.6 ± 4.1 years) patients with no previous orthodontic treatment were evaluated using cone-beam computed tomography. Axial and cross-sectional views were evaluated with regard to whether dehiscence and/or fenestration on buccal and lingual surfaces existed or not. For statistical analysis, the Pearson chi-square test was used at a P < .05 significance level.

RESULTS

According to the statistical analysis, the hypo-divergent group (6.56%) had lower dehiscence prevalence than the hyper-divergent (8.35%) and normo-divergent (8.18%) groups (P  =  .004). Higher prevalences of dehiscence and fenestration were found on buccal sides in all vertical growth patterns. While fenestration was a common finding for the maxillary alveolar region, dehiscence was a common finding in the mandible in all groups.

CONCLUSION

The null hypothesis was rejected. Although the prevalence of fenestrations was not different, significant differences for dehiscences were found in patients with different vertical growth patterns.

Dehiscence and fenestration in skeletal Class I, II, and III malocclusions assessed with cone-beam computed tomography

OBJECTIVE

To test the null hypothesis that the presence of dehiscence and fenestration was not different among patients with skeletal Class I, II, and III malocclusions.

MATERIALS AND METHODS

In this retrospective study, a total of 123 cone-beam computed tomography (CBCT) images were obtained with an iCAT scanner (Imaging Sciences International, Hatfield, Pa). Patients with normal vertical patterns were classified according to dental malocclusion and ANB angle. Class I comprised 41 patients-21 girls and 20 boys (mean age, 22.4 ± 4.5 years); Class II comprised 42 patients-22 girls and 20 boys (mean age, 21.5 ± 4.2 years); and Class III comprised 40 subjects-22 girls and 18 boys (mean age, 22.1 ± 4.5 years). A total of 3444 teeth were evaluated. Analysis of variance and Tukey's test were used for statistical comparisons at the P < .05 level.

RESULTS

Statistical analysis indicated that the Class II group had a greater prevalence of fenestration than the other groups (P < .001). No difference was found in the prevalence of dehiscence among the three groups. Although fenestration had greater prevalence in the maxilla, more dehiscence was found in the mandible for all groups. In Class I, alveolar defects (dehiscence, fenestration) were matched relatively in both jaws. Furthermore, Class II and Class III subjects had more alveolar defects (41.11% and 45.02%, respectively) in the mandible. Dehiscences were seen with greater frequency in the mandibular incisors of all groups.

CONCLUSION

The null hypothesis was rejected. Significant differences in the presence of fenestration were found among subjects with skeletal Class I, Class II, and Class III malocclusions. Fenestrations had greater prevalence in the maxilla, but more dehiscences were found in the mandible.

Effect of a self-etching adhesive containing an antibacterial monomer on clinical periodontal parameters and subgingival microbiologic composition in orthodontic patients

INTRODUCTION

The aims of this study were to evaluate the effect of a self-etching adhesive system containing an antibacterial monomer on periodontal health and subgingival microbiologic composition in orthodontic patients and to compare it with a conventional adhesive system.

METHODS

A split-mouth design was chosen, and 15 patients were included in the study. Brackets in contralateral quadrants were bonded with either a conventional adhesive system (control) or a self-etching adhesive system that contained an antibacterial monomer. Clinical periodontal parameters including plaque index, gingival index, probing depths, and bleeding on probing were determined. Subgingival plaque samples were collected before bracket placement (T0) and at the 6-month follow-up (T1). The real-time TaqMan polymerase chain reaction assay was used to determine the subgingival counts of Porphyromonas gingivalis, Tannerella forsythensis, Prevotella intermedia, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Campylobacter rectus. For clinical periodontal parameters, analysis of covariance (ANCOVA) and, for bacterial counts, Wilcoxon tests were used for statistical comparisons at the P <0.05 level.

RESULTS

Clinical periodontal parameters were not changed, and they were not different between the groups from T0 to T1. T forsythensis and F nucleatum increased during the treatment period in both groups (P <0.05). The majority of the bacteria were T nucleatum at T0 and T1 in both groups. Changes in bacterial load from T0 to T1 were not different between groups except for T forsythensis and F nucleatum (P <0.05).

CONCLUSIONS

The use of an antibacterial monomer did not have an additional positive effect on clinical periodontal parameters. When used in bonding orthodontic brackets, the antibacterial monomer failed to reduce periodontopathogenic bacteria when compared with the conventional adhesive system during a 6-month treatment period.

Relationship between iron-deficiency anemia and periodontal status in female patients

BACKGROUND

The aim of this study was to evaluate the periodontal status of patients with iron-deficiency anemia (IDA) and the correlation of changes in serum and gingival crevicular fluid (GCF) ferritin levels after periodontal therapy.

METHODS

Nineteen female patients with anemic hematologic values were classified as group A, and 20 healthy females with normal hematologic values were classified as group B. After group A was recruited, group B was enrolled with patients who had similar gingival indices as group A. At baseline and the 3-month follow-up visit, clinical periodontal indices and hematologic parameters were recorded, and GCF samples were taken. All patients received an oral hygiene-improvement session followed by scaling, and sites with >4-mm probing depths received root planing. At the 3-month follow-up visit, all measurements and analyses were repeated.

RESULTS

During the follow-up period, all clinical indices decreased in both groups (P <0.05), but the gingival index in group A did not change. The GCF ferritin concentration showed statistically significant decreases (P <0.05), but total amounts of ferritin in GCF did not change. No significant correlation was found between serum and GCF ferritin levels.

CONCLUSION

The findings of this study showed that changes in serum ferritin levels did not correlate with the GCF ferritin levels, and IDA was not a direct risk factor for periodontal diseases.

Effect of ED-71, a New Active Vitamin D Analog, on Bone Formation in an Orthopedically Expanded Suture in Rats. A Histomorphometric Study

OBJECTIVES

The aim of this experimental study was to evaluate the effects of ED-71, a new active vitamin D analog, on bone regeneration in response to expansion of the mid-palatal suture, in rats, histomorphometrically.

METHODS

Sixteen male 50-60 days old Wistar rats were separated into two equal groups (control and experimental). Both groups were subjected to expansion, and 30 grams of force was applied to the maxillary incisors with a helical-spring. Experimental group was treated with single-dose ED-71 (0.8 mug/kg body weight) in the mid-palatal suture locally and eight control animals received vehicle solution. Bone regeneration in the mid-palatal suture was evaluated by bone histomorphometric method and mineralized area (Md.Ar), fibrosis area (Fb.Ar), mineralized area/fibrosis area (Md.Ar/Fb.Ar), bone area (B.Ar) and osteoblast number (N.Ob) parameters were evaluated. Mann Whitney-U test was used for statistical evaluation at P<.05 level.

RESULTS

Statistical analysis showed significant differences between groups for all investigated histomorphometric parameters. Md.Ar (P<.001), Md.Ar/Fb.Ar (P<.001), B.Ar (P<.01) and N.Ob (P<.001) parameters were significantly increased and Fb.Ar (P<.001) measurement was significantly decreased in experimental group. ED-71 group with a mean of 24.55+/-6.47 showed statistically higher N.Ob than the control group (mean N.Ob: 12.82+/-5.81).

CONCLUSIONS

ED-71 has positive effects on early phase of bone regeneration in the mid-palatal suture in response to expansion and may be beneficial in routine maxillary expansion procedures.