Experimental investigation of relationship between trauma and bisphosphonate-related osteonecrosis.

BACKGROUND: Bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) disease is rare, but there are serious side-effects of BP therapy in patients. In some patients, surgery is needed and could not be cured. A standard test is not available showing the risk of jaw osteonecrosis in routine use. The measurement of serum C-terminal telopeptide (CTX) levels has been used in diseases of BRONJ resorption and antiresorptive therapy. AIM: This paper is aimed at investigating the relationship between traumatic procedures and presence of BP-related osteonecrosis. MATERIALS AND METHODS: Thirty male Wistar albino rats with weighing 200 ± 20 g were used for the experimental procedures. Rats were randomly divided into three groups each containing 10 rats as follows: Group 1 (traumatic extraction group), Group 2 (atraumatic extraction group), and Group 3 (control group). All groups, zoledronic acid (ZA) (0.3 mg/kg/week) [1] was diluted with physiological saline and given subcutaneously for 2 months. After the 2 months, Group 1 was subjected to traumatic extraction of right first lower molars, and Group 2 was subjected to atraumatic extractions of the right first lower molars. Group 3 was subjected to no extractions as a control group. Animals were euthanized 32 days after tooth extractions, and the ZA administration protocol was maintained until the animals' death. After sacrifice, blood samples were collected for C-terminal cross-linking telopeptide of type I collagen (CTX-1) levels, clinical and radiological findings were recorded. RESULTS: The bone resorption marker CTX-1 showed a significant difference among the groups. CTX-1 was measured significantly higher in blood samples of Group 2 (4.15 ± 0.34; P = 0.001) than Group 1 (3.77 ± 0.34; P = 0.0001). No, statistically significant changes were found between Groups 1 and 2 as for clinical and radiological assessment. CONCLUSION: This study provides preliminary observations for the development of an animal model of BRONJ. Although clinical and radiological findings were not relevant, serum CTX values are reliable biochemical markers for predicting BRONJ and also atraumatic surgical procedures are important to prevent BRONJ.

Influence of caffeic acid phenethyl ester on bone healing in a rat model.

OBJECTIVE: To examine the effects of caffeic acid phenethyl ester (CAPE; a component of honey bee-hive propolis with antioxidant, anti-inflammatory, antiviral and anticancer properties) on bone regeneration and fibrotic healing in a rat model. METHODS: Male Sprague-Dawley rats (n = 63; mean age 7 weeks; weight 280-490 g) were randomly divided into three groups: A, cranial defect with no bone healing treatment (n = 21); B, cranial defect treated with CAPE (n = 21); C, cranial defect treated with CAPE and ß-tricalcium phosphate/hydroxyl apatite (n = 21). Rats were anaesthetized with ketamine (8 mg/100 g) by intraperitoneal injection and a cranial critical size bone defect was created. Following surgery, CAPE (10 µmol/kg) was administered by daily intraperitoneal injection. Seven rats in each group were killed at days 7, 15 and 30 following surgery. Bone regeneration, fibrotic healing and osteoblast activity were evaluated by histopathology. RESULTS: Statistically significant differences in healing were found between all groups. There were no statistically significant within-group differences between day 7 and 15. At day 30, bone healing scores were significantly higher in groups B and C compared with group A. CONCLUSION: CAPE significantly improved bone-defect healing in a rat model, suggesting that CAPE has beneficial effects on bone healing.

The comparison of the effects of three types of piezoelectric ultrasonic tips and air polishing system on the filling materials: an in vitro study.

AIM: The aim of this study was to evaluate the effect of air polishing and different ultrasonic scaler inserts on dental fillings, such as amalgam, composite and porcelain. MATERIALS AND METHODS: This study was performed on amalgam, composite and porcelain samples. The surfaces of the samples were exposed to different type of piezoelectric ultrasonic scaler inserts and air-abrasive unit. The scaler inserts were Instrument A, Instrument PS and PI. The roughness of the surfaces of each sample were measured with a profilometer and observed by stereomicroscope. RESULTS: The stereomicroscopic images and profilometric values showed that Instrument A and PS resulted in rough surfaces, such as chips, nicks and scratches on the amalgam, composite and porcelain surfaces. The Instrument PI roughened the amalgam surface, but it did not roughen the porcelain or composite surfaces. The profilometric measurements (Ra) showed that the roughness of the surfaces depending on air polishing was less than the ultrasonically scaled surfaces. CONCLUSION: The wrong tip applications during dental scaling procedure cause roughness, such as scratches, nicks or chips, not only on the teeth surfaces but also on the filling materials. Thus, dental scaling procedure on the restorations should be performed carefully and the roughness sites on the restorations have to be re-polished after scaling to prevent plaque accumulation.

Gingival necrosis following the use of a paraformaldehyde-containing paste: a case report.

AIM: To report on an unusual case of gingival necrosis following the use of a paraformaldehyde-containing paste in root canal treatment. SUMMARY: Paraformaldehyde preparations are toxic to hard and soft tissues. In an era of effective local anaesthesia, toxic devitalizing preparations have few applications. However, in a mobile world population, severe tissue injury may occasionally be encountered after the use of paraformaldehyde or other toxic agents in some parts of the world. Dentists should avoid such preparations and be alert of the features and management of local toxicity if they encounter it in practice. KEY LEARNING POINTS: Paraformaldehyde-containing pastes have no application in contemporary dentistry. Dentists should avoid toxic preparations for pulp devitalization. Dentists should be aware of the features and management of tissue necrosis resulting from the use of toxic dressing materials.