Browsing School of Dentistry by Subject "Healing"
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The effect of electrical stimulation on success of bone grafts: an in vivo studyPurpose: Bone grafting is often unpredictable and is associated with reduced success rate, extended healing times and morbidity. Methods that expedite healing and increase predictability will contribute to the overall success of reconstructive efforts. In this project, the effect of electrical stimulation on bone graft healing in rat calvaria was examined. Materials and Methods: Fifteen adult male Sprague-Dawley rats were used. A 7 mm diameter bone defect at the midline of the calvarium was grafted using freeze-dried mineralized bone. Bipolar platinum stimulating electrodes were overlaid on top of the periosteum on the center of the graft. Animals were divided randomly into two groups. The experimental group (n=8) received electrical stimulation (3 times/day for 10 days) and the control group (n=7) received no stimulation. At 6 weeks, the grafted areas together with the surrounding bone were harvested from the cranium. Tissue sections (5-7 μm) were prepared and stained using hematoxylin and eosin. Mounted slides were analyzed and for each animal, the grafted area was marked and the percent of new bone, remaining graft material and connective tissue was calculated. Data was analyzed using ANOVA. A p≤.05 was considered significant. Results: There were statistically significant differences between the experimental and control group. The electrical stimulation group had significantly more (p=0.034) bone (3.81+3.6 %) compared to the control group (0.47+0.52%). The amount of remaining graft material was also significantly higher (p=0.024)in the control group (26.11+6.54%) compared to the stimulation group (16.64+5.28%). No significant difference (p=0.15) was found between the 2 groups in the amount of connective tissue (stimulation: 79+5.47%; control: 73.2+6.82%). Conclusion: In this animal model of bone graft healing, electrical stimulation resulted in significantly more bone formation and less remaining graft material. These findings suggest that electrical stimulation expedites bone graft healing.
The Effects of Local Antibiotic Administration on Endodontic Treatment OutcomesTeeth with periapical radiolucency have a lower prognosis than those without radiolucency and may take up to 4 years for complete healing after primary endodontic treatment. Local delivery of a non-toxic substance with antimicrobial and anti-inflammatory properties may improve the healing of apical periodontitis. The study was a randomized clinical trial to evaluate the effects of local administration of doxycycline or saline at the periapex of teeth with periapical lesions. The primary aim was to compare the change from baseline to 4 months in periapical radiolucency area between doxycyline and saline groups. The secondary aims were to compare the percentage of healed cases (no detectable periapical radiolucency) at 4 months between doxycycline and saline groups and to compare the post-obturation pain experience between doxycycline and saline groups. 20 single-rooted teeth with pulpal necrosis and periapical radiolucency ≥ 3mm were treated endodontically in two visits. Prior to obturation, doxycycline or saline was delivered through the apical foramen into the periapical tissues. Cone-beam computed tomography (CBCT) imaging of the tooth and periapical tissues was performed post-op and at 4 month recall. All patients reported their post-obturation pain experience using a Visual Analogue Scale (VAS). There was no significant difference when comparing the change from baseline to 4 months in periapical radiolucency area between doxycycline and saline groups (p = 0.36, One-Way ANOVA). There was no difference when comparing the percentage of healed cases (no detectable periapical radiolucency) at 4 months between groups. All patients had mild (<30/100 VAS) to no pain that uniformly resolved within 7 days. There was no significant difference when comparing VAS scores between groups (p > 0.05, One-Way ANOVA controlling for level of pre-op pain using a linear regression model). The local administration of doxycycline at the periapex of teeth with periapical lesions did not significantly improve healing of periapical radiolucencies at 4-months. It did, however, show potential as a clinically important adjunct that warrants future research. Doxycycline did not appear to have any deleterious effects upon healing of periapical lesions and it was not associated with significant increases in post-operative pain.
Evaluation of Factors Related to Long-term Healing in Endodontic TreatmentIntroduction: This study sought to determine the effects of residual root canal bacteria and treatment factors on endodontic treatment outcomes up to 6 years post-operatively using traditional radiography (PA radiographs) and limited cone beam computed tomography (CBCT). Methods: Root canal samples were obtained from 50 patients with pulp necrosis and a periapical lesion, following two-visit treatment using contemporary chemomechanical preparation techniques. PCR, with broad range 16S rDNA bacterial primers, was performed followed by cloning and sequencing on pre-obturation specimens. Periapical and CBCT radiographs were taken at 10 months to 6 years post-treatment. Images were scored by two blinded, calibrated endodontists using the conventional periapical index (PAI) and a CBCT index. Statistical analysis was performed using bivariate and multivariate regression analysis for treatment factors. Kaplan-Meier survival analysis and Pearson's regression analysis was used for year-over-year changes. Results: 41 patients were included in the final data analysis. Recall decreased from 98% at 10-17 months to 51% at 33+ months. The percentage of patients healed at 10-17 months, 18-32 months and 33+ months and overall was 65%, 63%, and 66% respectively. Factors influencing outcomes were presence of bacteria at time of obturation (56% when present, 81% absent), primary versus persistent disease (71% vs. 39%), tooth type (85% anterior,23% molar), obturation to the radiographic apex (100% to the apex, 56% not to the apex), and larger master apical file sizes (73%MAF>45 vs. 36% MAF<45).. Short-term outcomes had a strong positive relationship with final outcome (Pearson's, r2=0.56, p=<0.01). Conclusions: Bacterial DNA presence at the time of obturation adversely affects short-term and intermediate-term endodontic treatment outcomes, but this effect is not found in the long-term. Various patient factors such as tooth type and treatment factors such as master apical file size influence outcomes. Short-term treatment outcomes are good predictors of long-term outcomes.
The Relationship Between Short Term Healing of Periapical Lesions and Glycemic Control: A Pilot StudyThe aim of this study was to evaluate the relationship between HbA1c level and short-term healing of periapical lesions after non-surgical root canal treatment (NSRCT). After NSRCT, digital periapical radiographs were taken and blood samples were drawn for HbA1c analysis. To assess short-term healing (PAI difference), subjects returned after six months for a radiograph and blood draw. A calibration exercise established the reliability of the PAI scoring process. Thirty-eight subjects returned for the recall. The relationship between HbA1c level and also the co-variables, with healing was explained using Spearman’s rho and logistic regression. There was a significant correlation between healing and HbA1c level (rs = -.52, p ≤.0001), age (rs = -.44, p ≤.003), recall days (rs =.29, p ≤.036), and cardiovascular status (rs = -.34, p ≤.018). A final logistic regression showed a significant relationship between HbA1c level and short-term healing of periapical lesions (R = .62, p≤ .05).