mahnaz arshad

This study aimed to evaluate the shear bond strength (SBS) of two repair composites (Crea.lign vs. PermaFlo) to a base metal alloy and zirconia ceramic.

Sixty-four discs (12mm diameter, 1mm thickness) were fabricated using Wirobond base metal alloy and zirconia. They were then bonded with their respective composite resins (N=16) in each of the two porcelain chipping repair kit subgroups consisting of PermaFlo and Crea.lign. All specimens were stored in 37°C distilled water for 24 hours. Half of them were subjected to 10,000 thermal cycles (5-55°C, 30s). All specimens were tested for SBS with a universal testing machine. Failure types were analyzed using a digital camera. Analysis of the data was done by two-way ANOVA and Bonferroni post-hoc tests.

SBS was significantly affected by the type of composite resin. PermaFlo had a significantly higher SBS than Crea.lign to base metal alloy (P<0.001) and zirconia ceramic (P<0.001). Thermocycling decreased the SBS of both composites to base metal alloy (P<0.001) and zirconia (P<0.001).

A universal adhesive could provide higher shear bond strength of zirconia and base metal alloy to composite resin than Crea.lign composite and the MKZ primer supplied by its manufacturer. 

Phototherapy with a light-emitting diode (LED) is used in medicine due to its potential bio-stimulatory effects on the human body. However, controversy still exists regarding the efficacy of low-level laser therapy (LLLT) and phototherapy with LED. This in vivo study aimed to quantitatively and qualitatively assess the newly formed bone following LED phototherapy of the human maxillary sinuses.

This randomized clinical trial (concurrent parallel) was conducted on 44 patients in two groups (n=22) at the Implant Department of Tehran University of Medical Sciences. Randomization was done by a random sequence generator program. The inclusion criteria were absence of chronic sinusitis and chronic bone marrow conditions, no history of surgery at the site, absence of diabetes mellitus, no history of chemotherapy or radiotherapy, maxillary premolar edentulism, and signing informed consent forms. Group A underwent LED phototherapy with 620 ± 2 nm wavelength for 20 minutes daily for a total of 21 days after sinus lift surgery. Group B served as the control group and did not receive phototherapy. After 6 months, the grafted sites were re-opened for implant placement, and bone biopsy samples were obtained using a trephine bur. The samples were stained with hematoxylin and eosin and inspected under a light microscope. The results were statistically analyzed using the Mann-Whitney U test. Both the surgeon and pathologist were blinded to the group allocation of patients.

Forty tissue specimens were analyzed. Insignificant differences existed between the two groups in terms of the degree of inflammation, bone quality, and maturity of collagen. Histological analyses revealed no significant difference in the mineralized areas of bone between the two groups (P>0.05).

The results indicated that LED phototherapy cannot significantly enhance osteogenesis after sinus lift surgery. No side effects were observed in the experimental group.

The success of implant treatment depends on many factors affecting the bone-implant, implant-abutment, and abutment-prosthesis interfaces. Stress distribution in bone plays a major role in success/failure of dental implants. This study aimed to assess the pattern of stress distribution in bone and abutment-implant interface under static and cyclic loadings using finite element analysis (FEA).

In this study, ITI implants (4.1×12 mm) placed at the second premolar site with Synocta abutments and metal-ceramic crowns were simulated using SolidWorks 2007 and ABAQUS software. The bone-implant contact was assumed to be 100%. The abutments were tightened with 35 Ncm preload torque according to the manufacturer’s instructions. Static and cyclic loads were applied in axial (116 Ncm), lingual (18 Ncm), and mesiodistal (24 Ncm) directions. The maximum von Mises stress and strain values ​​were recorded.

The maximum stress concentration was at the abutment neck during both static and cyclic loadings. Also, maximum stress concentration was observed in the cortical bone. The loading stress was higher in cyclic than static loading.

Within the limitations of this study, it can be concluded that the level of stress in single-unit implant restorations is within the tolerable range by bone.

This study aimed to assess the effect of application of two types of zirconia primers on repair bond strength of composite to zirconia ceramic.

In this in vitro, experimental study, 60 zirconia blocks were divided into five groups and subjected to the application of Z-Prime Plus (ZPP), Monobond Plus (MBP), Porcelain Bonding Resin (PBR), ZPP followed by PBR (ZPP+PBR) and MBP followed by PBR (MBP+PBR). They were then bonded to Z100 composite. The samples were then immersed in water at 37°C for 24 hours, thermocycled for 1000 cycles between 5-55°C and subjected to shear bond strength (SBS) test. The mode of failure was determined under a stereomicroscope and a scanning electron microscope (SEM).

The mean bond strength was the highest in ZPP+PBR group followed by MBP+PBR, ZPP, PBR and MBP group (22.29±8.86, 15.75±2.81, 12.02±3.24, 3.60±2.92 and 2.92±1.78 MPa, respectively). The effects of type of zirconia primer and use/no use of PBR on SBS were significant (P<0.05). The frequency of adhesive failure in MBP and PBR groups was significantly higher than that in MBP+PBR and ZPP+PBR groups (P<0.05). The cohesive failure was significantly more frequent in ZPP+PBR group than in ZPP, MBP and PBR groups (P<0.05).

Simultaneous application of zirconia primer and PBR is the most efficient technique for repair of all-ceramic zirconia restorations with composite resin.

Solubility is an important property of luting cements in determining clinical durability. The aim of this study was to compare the solubility of Panavia, Calibra and Maxcem resin cements with that of GC Fuji PLUS resin modified glass ionomer cement in three different pH values.
A total of 96 specimens were prepared (8mm diameter, 4mm thickness) according to manufacturer instructions. After setting, they were desiccated and weighed. The specimens were kept immersed in distilled water and lactic acid solution (pH values of 3 and 5) for 30 days and then removed and weighed again. Data were statistically analyzed by SPSS18 using two-way ANOVA with P≤0.05 set as the level of significance.
The results of this study showed no significant difference between three pH values (P=0.08). The Calibra resin cement had the lowest value of solubility in distilled water and both pH of lactic acid. GC Fuji PLUS resin modified glass ionomer cement had the highest value of solubility in lactic acid and the Maxcem resin cement had the highest value of solubility in water.
The solubility characteristics of resin modified glass ionomer and three different resin cements were significantly affected by their composition and the storage condition.

Pain control by local anesthesia plays a critical role in success of most dental treatments. Due to the unpleasant pain experience related to the use ofthe conventional syringe injection, some computerized techniques have been developed for local anesthetic injection. This study aimed to compare the pain score following infiltration anesthesia of the maxillary premolar teeth administered by the conventional syringe and automatic.
This single-bind randomized clinical trial was performed on 35 patients whose average age was 38. Requiring bilateral extraction of maxillary premolars. The patients’ dental anxiety was scored and they received infiltration anesthesia with the iCT injection SE (Dentium, South Korea) at one side and conventional syringe at the contralateral side. The pain level was recorded during needle insertion, anesthetic delivery and 5 hours after the injection using visual analog scale (VAS) and the face rating scale (FRS). The data were subjected to Wilcoxon signed-rank test.
Significant differences were found between the automatic and conventional method sregarding pain scores duringneedle insertion (P Both FRS and VAS in iCT injection showed that frequency of severe pain during needle insertion and anesthetic delivery was noticeably lower than that in conventional injection method but findings revealed that there was no significant difference between these two technics after 5 hours of injection.

Reconstruction of a facial defect is a complex modality either surgically or prosthetically, depending on the site, size, etiology, severity, age, and the patient’s expectation. Loss of an auricle, in the presence of an auditory canal, affects hearing, because the auricle gathers sound and directs it into the canal. The auricle acts as a resonator to slightly amplify lower frequency sounds and helps to localize sounds, especially in conjunction with the other ear. Osseointegrated implants have an important role in prosthetic reconstruction of patients with craniofacial defects. The main indications of this treatment plan are lack of local tissue for autogenous reconstruction, previous reconstruction failure and selection of this technique by the patient. This paper presents a clinical case and advantages of the osseointegrated implant technique for retention of auricular prostheses.

This case report presents a 16-year-old boy with bilateral temporomandibular joint (TMJ) bony ankylosis due to trauma. The patient had undergone several unsuccessful therapeutic surgeries and was experiencing reduced mouth opening, difficulty in eating and speaking, poor oral hygiene, snoring, and depression. Bilateral gap arthroplasty and distraction osteogenesis (DO) were performed. After the surgery, we were able to move the osteodistractors forward and prevent the upward and backward movement of the proximal mandibular segment with the use of our custom-made Sh-device, which allowed bone growth and soft-tissue matching. The mandibular deficiency was treated, and the patient's sleep quality significantly improved after three months. The physical, orthodontic and speech therapies were continued. The facial asymmetry, difficulty in sleeping, eating and speaking, and low self-esteem were completely resolved. At the 8-year follow-up, the patient's condition was satisfactory. The Sh-device can be used as a contemporary treatment modality for TMJ ankylosis.

It is estimated that one-third of the people with refractory epilepsy suffer from obstructive sleep apnea (OSA). In a patient presenting with OSA symptoms and epilepsy, removing a portion of the soft palate (uvulopalatoplasty) can be considered the treatment of choice for eliminating the OSA and decreasing the seizures.Here, we report the results of our surgical approach by which the patient’s problems completely resolved, and we observed no symptoms of OSA or epilepsy after the surgery. After 10 years of follow-up, the patient is seizure-free and does not need any antiepileptic drugs.

Subcondylar fractures are common in the maxillofacial region following direct trauma to the mandibular ramus. The literature is replete with articles written on the treatment of subcondylar fractures, encompassing a plethora of various surgical approaches; however, the best treatment procedure has remained controversial. Such fractures are either treated by open reduction with internal fixation or closed reduction with maxillomandibular fixation. In this article, we describe a new surgical method for treatment of subcondylar fractures.

Microbial leakage through the implant-abutment (I-A) interface results in bacterial colonization in two-piece implants. The aim of this study was to compare microleakage rates in three types of Replace abutments namely Snappy, GoldAdapt, and customized ceramic using radiotracing.
Three groups, one for each abutment type, of five implants and one positive and one negative control were considered (a total of 17 regular body implants). A torque of 35 N/cm was applied to the abutments. The samples were immersed in thallium 201 radioisotope solution for 24 hours to let the radiotracers leak through the I-A interface. Then, gamma photons received from the radiotracers were counted using a gamma counter device. In the next phase, cyclic fatigue loading process was applied followed by the same steps of immersion in the radioactive solution and photon counting.
Rate of microleakage significantly increased (P≤0.05) in all three types of abutments (i.e. Snappy, GoldAdapt, and ceramic) after cyclic loading. No statistically significant differences were observed between abutment types after cyclic loading.
Microleakage significantly increases after cyclic loading in all three Replace abutments (GoldAdapt, Snappy, ceramic). Lowest microleakage before and after cyclic loading was observed in GoldAdapt followed by Snappy and ceramic.

Introducation: The long-term outcome and clinical results of gaparthroplasty used for the treatment of condylar ankylosis of the mandible in children with application of postoperative activator appliances and costochondral rib graft are evaluated and compared. The purpose of this study was to compare the effect of gap arthroplasty and costochondral graft methods on reankylosis, a mount of mouth opening and growth. A non-randomized, retrospective clinical study of l0 cases (5-12 years old) of condylar ankylosis of the mandible, surgically treated during a 10 year period from 2002 to 2012 was performed. Four patients were treated by condylectomy and interpositional flap, whereas six were treated by condylectomy and immediate costachondral rib grafts. The first group underwent long-term postoperative therapy using removable activator appliances. Casts, radiographs, photographs, and computed tomography (CT) were used post surgically to evaluate rib graft, condylar growth and function, occlusion, facial, and condylar symmetry. Data were analyzed by SPSS 16 statistical software using Mann-Whitney, Paired T-test and Chi-square tests. Children with long-standing condylar ankylosis of the mandible treated by condylectomy and interpositional flap showed more favorably when activators were used post-surgically. Gaparthroplasty with functional activator post-operatively can be considering for TMJ ankylosis.

Radioisotopes adhere to any surface in which they come in contact. Covering the sample surface with a suitable material prior to submersion and isolation of the material before counting make it possible to evaluate the penetrating radioisotopes within the interfacial area. The aim of this study was to determine a suitable material to cover implant and abutment in evaluation of microleakage in implant-abutment interface using radiotracers and gamma counter.

In this in vitro study, 46 samples were selected and divided into two groups. The first group consisted of implant samples covered with putty, nail polish and putty-super glue with 1mm distance from the interface. The second group included non-implant samples covered with putty, autopolymerizing acrylic resin, and nail polish. This group was used for evaluation of adherence levels of the radioisotopes. Microleakage test was performed with thallium-201 and gamma counting in three phases: 1) after removing samples from thallium solution, 2) after washout of samples, and 3) after removing covering materials. In order to compare penetration of radioisotopes within the samples analysis of co-variance was carried out.

There were statistically significant differences between three phases of gamma counting and between samples in different implant groups. Microleakage of implant-putty-glue was significantly less than that of implant-putty (217343.40± 86007.926). Similarly, implant-putty showed a significantly less microleakage than implant- nail polish. (313247.20±67933.031).

The best material among the ones considered in this study turned to be putty sealed by super glue. Contrarily, nail polish was not considered suitable due to increased microleakage.

Supernumerary tooth is a rare event, which is usually found coincidentally in radiographic examination. The prevalence of this event is 1-3% with different prevalence for primary and permanent dentition. Supernumerary teeth may cause various clinical problems including: delayed or failure of eruption, displacement or rotation of permanent teeth and cyst formation. The purpose of this study was to present the case of a 9-year-old boy who had a large dentigerous cyst around his primary mandibular left premolar that was enucleated with the tooth. A year after this enucleation, we have observed a supernumerary tooth in mesial of canine. It is a reasonable question that “can the supernumerary tooth formation relate to the dentigerous cyst around impacted tooth?” Therefore, it is necessary to perform more pathological investigation in this aspect to answer this question.

Vermilion irregularities are common secondary deformities after cleft lip repair, regressed or resected hemangiomas, trauma and tumor surgeries. Vermilion deficiency attracts considerable attention and detracts from an otherwise excellent lip repair. Minor and moderate vermilion defects can be corrected with upper lip advancement, rotation flaps, tongue flaps or grafts. Major defects defy correction with local flaps. A technique is described for correction of large absolute tissue defects of the vermilion using Mutual Cross-Lip Musculomucosal Flaps (MCLMF) Or Ahmad-Ali's flaps. This technique was applied in eight patients with major vermilion defects secondary to hemangioma regression, neoplasia, and trauma. Reconstruction with MCLMF led to create a balanced donor and recipient lips appearance and function. There were no postoperative complications. Surgical results were satisfactory in all patients, and sufficient lip mobility with adequate bulk was maintained. One patient demonstrated minimal transient lip tightening. Use of Ahmad-Ali's flaps in selected patients resulted in successful reconstruction of severe vermilion defects.

Supernumerary tooth is a rare event, which is usually found coincidentally in radiographic examination. The prevalence of this event is 1-3% with different prevalence for primary and permanent dentition. Supernumerary teeth may cause various clinical problems including: delayed or failure of eruption, displacement or rotation of permanent teeth and cyst formation.
The purpose of this study was to present the case of a 9-year-old boy who had a large dentigerous cyst around his primary mandibular left premolar that was enucleated with the tooth. A year after this enucleation, we have observed a supernumerary tooth in mesial of canine. It is a reasonable question that “can the supernumerary tooth formation relate to the dentigerous cyst around impacted tooth?”
Therefore, it is necessary to perform more pathological investigation in this aspect to answer this question.

A complete knowledge of bone healing is a prerequisite to many decision makings in dentistry and is considered as a basic event in some research strategies. Any method that can accurately monitor the healing process is important to clinician providing the information required for further treatment planning. Our study shows a simple and reliable method to evaluate the events that occur during socket healing in rats. Thirty five "Sprague - dawly" male rats were selected. All rats were anesthetized with intra peritoneal injection of Ketamin 10% and Xylazine 2% at the dose of 2 mUkg on day I. Mandibular left first molars were extracted with the use of very small excavator and hemostat forceps. At the same day,7,14,21,28,45 and 60 days after extractions, five rats were sacrificd, the left mandibles were removed and placed into 10% Formalinc. Muscles and gingival tissue were dissected away the Following day and the mandible was placed on a radiographic film and the buccul views were taken. The radiographs were scanned and analyzed with Avcnd (program that designed in matlab 6.1). Increased density of the image of apical and crestal areas of the socket was observed on day 7. The maximum density of apical area was reached on day 28 and preceded towards crestal area on day 60. Density increasing in the crestal area is slower than apical area. Densitometrie evaluation of extraction socket healing using Avend program is useful and reliable to objectively assess bone formation and mineralization.