saeid tavanafar

Both low-level laser therapy (LLLT) and platelet-rich plasma (PRP) are demonstrated to promote the repair of mandibular defects.

This study investigated the mechanical properties and calcium content at the tooth extraction site in a rat model exposed to LLLT ( = 808 nm) with or without PRP.

In this experimental rat model study, the left first molar maxillary teeth were extracted in twenty male rats. Then, the animals were randomly divided into four groups. Group one: after extraction, the extraction sockets were treated with 0.9Wgalliumaluminum- arsenide (GaAlAs) diode laser irradiation for five minutes every 72 hours for the next 12 days (4 times overall); group two: PRP was placed in the extraction sockets; group three: a combination of both treatments (LLLT+PRP) was applied; group four: the extraction sockets remained untreated (the control group). All rats were sacrificed 30 days post-operative. All bone blocks of the extracted socket were prepared for mechanical strength and calcium content analyses. Mann-Whitney test, one-way ANOVA test, and post hoc Fisher’s least significant difference (LSD) were used to analyze the data. A P-value less than 0.05 was considered significant. All analyses were performed by SPSS 16.0. The graph is illustrated in the graph pad 5.

The compressive strength in the laser group was significantly higher than in the control and PRP-treated groups (P = 0.0001 and 0.00044, respectively). Compared to the control and PRP groups, the effects of a combination of PRP and LLLT mechanical strength were statistically similar. Calcium content was influenced by none of the treatments.

The mechanical strength of the bone blocks was significantly stronger in the LLLT group than in the other groups. Platelet-rich plasma alone or combined with LLLT demonstrated a synergistic impact on neither mechanical strength nor calcium content.

Statement of the Problem: 

The administration of both platelet rich plasma (PRP) and silicon dioxide (SiO2) to the bone defects accelerates bone repair and regeneration. Application of both of them may show synergistic regenerative effects. 

Our objective was to evaluate the possible synergistic osteogenic effects of PRP and SiO2 by injecting them using an ad hoc device.

In this experimental study, PRP/SiO2 scaffolds were fabricated by in situ casting method with the help of CaCl2 as the gelation factor and alginate as the stroma; and then, the biodegradability and spatial arrangement were assessed. The injectable scaffold was introduced into the 40 rabbit mandibular defects by an ad hoc two-channel injecting device. Five defects received PRP/SiO2/alginate as the treatment; the other sets of defects were treated by PRP/alginate, SiO2/alginate, and the last five defects served as the control groups by getting only alginate injections. The osteogenicity of the scaffolds was evaluated by radiological and histological procedures; they were then compared with each other. Analysis of variance and least significant difference tests were used to analyze the data.

The SiO2-treated group showed a significant higher bone area compared to PRP/ SiO2-treated groups on day 40 (p= 0.013). The number of osteocytes was higher in SiO2-treated than the control groups on both 20 and 40 days (p= 0.032 and 0.022, respectively). The number of osteoclast was also higher in SiO2-treated than PRP-treated group (p= 0.028). In addition, the cells of this group had just started to create Haversian systems in newly formed bone tissues.

Silica demonstrated a superior osteogenic activity over PRP in both short and long term periods. Evidently, they showed no synergistic regenerative effects. Our ad hoc device was efficiently capable of inserting the scaffolds into the injured sites with no difficulties or complications.

Ameloblastoma is one of the most common benign epithelial odontogenic tumors of jaws. We report a case of long-standing slow-growing giant ameloblastoma involving almost all of mandibular bone. The solid multicystic lesion was excised, and the histopathological examination showed the follicular type of ameloblastoma. Furthermore, the defect was reconstructed with microvascular osteocutaneous free fibular graft.

An oro-antral fistula (OAF) creates a passage for oral microbes into maxillary sinus with numerous possible complications. This retrospective study evaluates the success of three different surgical techniques of OAF repair. Records of patients that were treated for OAF repair were retrieved and reviewed. Data recorded were patients’ age, gender, etiology, size, location, duration, and method of repair. According to the surgical technique used to repair the OAF, patients were divided into three groups including buccal flap, palatal flap, and buccal fat pad. All of the patients were locally anesthetized with 2% lidocaine and 1/100000 or 1/80000 epinephrine. Then the edges of the fistula were excised and fistula wall was dissected in a stitched layer by three surgical methods. The three groups were compared concerning the success or failure of surgical technique based on complete closure of OAF after three months postoperatively. 147 patients (116 males and 31 females) with adequate records were included in the study. The surgical methods used in patients were, buccal flap in 59 (40.1%), buccal fat pad in 42 (40.8%), and palatal flap in 28 (19%) individuals. Success rates of these techniques were significantly different. Buccal fat pad was the most successful flap (98.3%), followed by buccal flap (89.8%), and palatal flap (85.7%). The most common cause of OAF in this group of patients was dental extraction. Buccal fat pad flap seems to be one of the best treatments for the closure of OAF lager than 5 mm.

Tapia’s syndrome is an infrequent complication of airway manipulation. It is usually due to an extra-cranial ipsilateral injury to the hypoglossal nerve and the recurrent laryngeal branch of the vagal nerve, which can happen after any surgery. It is usually characterized by unilateral paralysis of the muscle of the tongue and vocal cords although it can also occur bilaterally. We present a patient with postoperative unilateral hypoglossal and recurrent laryngeal nerves palsy that occurred after cosmetic malar augmentation for esthetic correction of the left cheek flatness with an uncomplicated transnasal intubation. We report the first case of Tapia’s syndrome after porous polyethylene implantation for cosmetic cheek reconstruction. The patient was treated immediately after the diagnosis with 0.5mg dexamethasone for two weeks. After three months, the movements of the vocal cord and tongue movement started to improve and the patient’s hoarseness fully recovered after six months.

During root canal preparation, apical extrusion of debris can cause inflammation, flare-ups, and delayed healing. Therefore, instrumentation techniques that cause the least extrusion of debris are desirable. This study aimed to compare apical extrusion of debris by five single-file, full-sequence rotary and reciprocating systems.
One hundred twenty human mandibular premolars with similar root lengths, apical diameters, and canal curvatures were selected and randomly assigned to six groups (n=20): Reciproc R25 (25, 0.08), WaveOne Primary (25, 0.08), OneShape (25, 0.06), F360 (25, 0.04), Neoniti A1 (25, 0.08), and ProTaper Universal. Instrumentation of the root canals was performed in accordance with the manufacturers’ instructions. Each tooth's debris was collected in a pre-weighed vial. After drying the debris in an incubator, the mass was measured three times consecutively; the mean was then calculated. The preparation time by each system was also measured. For data analysis, one-way ANOVA and Games-Howell post hoc test were used.
The mean masses (±standard deviation) of the apical debris were as follows: 2.071±1.38mg (ProTaper Universal), 1.702±1.306mg (Neoniti A1), 1.295±0.839mg (OneShape), 1.109±0.676mg (WaveOne), 0.976±0.478mg (Reciproc) and 0.797±0.531mg (F360). Compared to ProTaper Universal, F360 generated significantly less debris (P=0.02). The ProTaper system required the longest preparation time (mean=88.6 seconds); the Reciproc (P=0.008), OneShape (P=0.006), and F360 (P=0.001) required significantly less time (P All instruments caused extrusion of debris through the apex. The F360 produced significantly less debris than did the ProTaper Universal.

White spots and enamel demineralization around orthodontic brackets are among the most important complications resulting from orthodontic treatments. Since the antibacterial properties of metals and metallic particles have been well documented, the aim of this study was to assess the antibacterial effect of stainless steel orthodontic brackets coated with silver (Ag) particles.
In this study, 40 standard metal brackets were divided into two groups of 20 cases and 20 controls. The brackets in the case group were coated with Ag particles using an electroplating method. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to assess the adequacy of the coating process. In addition, antibacterial tests, i.e., disk diffusion and direct contact tests were performed at three, six, 24and 48 hours, and 15 and 30 days using a Streptococcus mutans strain. The results were analyzed using Student’s t-test and repeated measures ANOVA.
Brackets coated with Ag, via an electroplating method, exhibited antibacterial properties when placed in direct contact with Streptococcus mutans. This antibacterial effect persisted for 30 days after contact with the bacteria.

Working length determination is important in successful endodontic treatment and retreatment.This study evaluated the accuracy of two electronic apex locators Root ZX and Raypex®6 (EALs) in determining the electronic working length (EWL) of the root canals in endodontic treatment and retreatment.
Access cavities were prepared on forty extracted, single-rooted human teeth and the actual working length (AWL) of the canals was determined. In the first phase of the study, primary EWL of un-instrumented teeth was measured and compared between two EALs. In phase II, all of the teeth were pre-flared and divided into the control(n=10) and the retreatment groups (n=30). Canals in the retreatment group were obturated by the lateral condensation technique using Gutta percha and sealer. After 15 days, gutta-percha was removed, and then the secondary EWL was recorded and compared between the two devices, in treatment and retreatment groups. Data were analysed by paired t-test and t-test.
Significant differences were found between both EALs in treatment and retreatment phases of the study (p Accuracy of the two EALs was similar and acceptable. EWLs determined by Root ZX were closer to the AWL. The EWL determination after pre-flaring improved the accuracy of EALs and root canal obturation remnant materials did not have any clear effect on the accuracy of these EALs.

Statement of the Problem: Vertical root fractures are catastrophic events that often result in tooth extraction. Many contributing factor are associated with increasing incidence of vertical root fracture. Root canal preparation is one of the predisposing factors which can increase the root susceptibility to vertical fracture. The aim of this study was to compare the effects of three different instrumentation techniques on vertical root fracture resistance of endodontically treated teeth. In this study, 120 freshly extracted mandibular premolar teeth of similar dimensions were decoronated and randomly divided into control (n=30), nickel-titanium hand K-file (HF, n=30), BioRaCe rotary file (BR, n=30), and WaveOne reciprocating single-file (WO, n=30) groups. After cleaning and shaping the root canals, AH26 was used as canal sealer, and obturation was completed using the continuous wave technique. The root canals were embedded vertically in standardised autopolymerising acrylic resin blocks, and subjected to a vertical load to cause vertical root fracture. The forces required to induce fractures were measured using a universal testing machine. ANOVA and Tukey’s post-hoc test were used to analyse the data. All experimental groups showed statistically significant reductions in fracture resistance as compared with the control group. There was a statistically significant difference between the HF and BR groups. The WO group did not differ significantly from the HF group or the BR group. All three instrumentation techniques caused weakening of the structure of the roots, and rendered them susceptible to fracture under lesser load than unprepared roots. The fracture resistance of roots prepared with the single-file reciprocating technique was similar to that of those prepared with NiTi hand and rotary instrumentation techniques.