The Effect of Parathyroid Hormone on Osseointegration in Insulin-Treated Diabetic Rats.

OBJECTIVES Uncontrolled diabetes mellitus is associated with impaired osseointegration. Diabetic individuals might benefit from bone anabolic therapies. Intermittent administration of 1-34 parathyroid hormone (PTH) stimulates bone formation in rodent models. However, this anabolic effect fails in diabetic rats. Whether the anabolic effect of PTH can be achieved in insulin-controlled diabetic rats has not been investigated yet. MATERIALS AND METHODS After diabetes induction with streptozotocin in 40 female Wistar rats, the animals were randomly divided into 4 groups: diabetes, diabetes plus PTH, insulin-treated diabetes, and insulin-treated diabetes plus PTH. After 1 week, miniscrews were inserted in the tibiae. Osmotic pumps with insulin or saline solution were implanted. Animals received 60 mg/kg PTH or saline solution. Histomorphometric analysis was performed. RESULTS In diabetic rats, no changes of medullary periimplant bone area or bone-to-implant contacts (BICs) were achieved with or without treatment with PTH. However, also animals treated with insulin failed to response significantly to PTH regarding bone area (7.4 ± 4.1% and 8.1 ± 4.1%) and BICs (33.7 ± 16.9% and 49.9 ± 11.9%). CONCLUSION These results demonstrate that the metabolic characteristics of the diabetic rats produced a condition unable to respond to PTH treatment, even when hyperglycemia was controlled with insulin

Prevalence and severity of periodontal disease in a historical Austrian population.

Objective: To assess the prevalence and severity of periodontitis based on different diagnostic methods in a historical Austrian population from the early middle ages. Background: The description of the oral health status of archaeological material can provide interesting insights into prevalence, severity, and extent of oral diseases. Herein, the periodontal health status of the skeletal remains of medieval Avars (700-800 AD), which were considered as one of the earliest Avarian settlements in Austria, was investigated. Methods: The skeletal remains of 128 Avars were examined; age and gender were estimated by standard forensic methods and tooth loss and root caries were recorded. Periodontitis was assessed by (a) measurement of the alveolar bone levels (ABL) and (b) evaluation of the interdental septa. Results: A mean ABL of 4.8 mm was determined, root caries tended to accumulate in teeth with a higher alveolar bone loss, and on average, 6.2 teeth were lost antemortem. Independent of the diagnostic method >90% of the subjects were judged as periodontally diseased, and age and tooth type were significant predictors. However, on the tooth level the presence of periodontitis varied considerably depending on the diagnostic method; that is, 7.6% versus 47.2% of the teeth were judged as healthy based on ABL or interdental septa, respectively. Conclusion: The periodontal status of the skeletal remains of medieval Avars revealed a considerable high prevalence of periodontitis (ie, >90% of this population displayed periodontal tissue breakdown). However, the diagnostic method, disease definition, and data presentation should be considered when comparing results of archaeological material

Comparison of marginal fit of cemented zirconia copings manufactured after digital impression with lava™ C.O.S and conventional impression technique.

BACKGROUND Evaluation of the marginal fit of cemented zirconia copings manufactured after digital impression with Lava™ Chairside Oral Scanner in comparison to that of zirconia copings manufactured after conventional impressions with polyvinyl siloxane. METHODS A prepared typodont tooth #36, was replicated 40 times with a vinyl silicone and precise model resin. The dies were randomly divided into two groups according to the impression taking technique. Digital impressions with Lava™ C.O.S. and conventional impressions were taken according to the group. Subsequently zirconia copings were manufactured and cemented on their respective dies with zinc oxide phosphate cement. After embedding in resin, mesio-distal section of each coping was performed with a diamond saw in order to obtain two slices. One half of the specimen was used for evaluation with an optical microscope (OM) and the other half for evaluation with a scanning electron microscope (SEM). Marginal gap (MG) and absolute marginal discrepancy (AMD) were measured mesial and distal on each slice. RESULTS No significant difference of the marginal parameters between the digital and the conventional group was found. The mean values for MG in the digital group were 96.28 μm (+/-43.21 μm) measured with the OM and 99.26 μm (+/-48.73 μm) measured with the SEM, respectively. AMD mean values were 191.54 μm (+/-85.42 μm) measured with the optical microscope and 211.6 μm (+/-96.55 μm) with the SEM. For the conventional group the mean MG values were 94.84 μm (+/-50.77 μm) measured with the OM and 83.37 μm (+/-44.38 μm) measured with the SEM, respectively. AMD mean values were 158.60 μm (+/-69.14 μm) for the OM and 152.72 μm (+/-72.36) for the SEM. CONCLUSIONS Copings manufactured after digital impression with Lava™ C.O.S. show comparable marginal parameters with the copings manufactured after conventional impression with polyvinyl syloxane. The mean MG values of both groups fit in the clinically acceptable range

Additional file 1: of Comparison of marginal fit of cemented zirconia copings manufactured after digital impression with lava™ C.O.S and conventional impression technique

Dauti et al._raw data. Description of data: Results showing MG and AMD in mesial and distal position for the digital and conventional group measured with the SEM and the optical microscope. Furthermore the results after additional experiments using the silicone replica technique are shown. (PDF 31 kb