The efficacy of intra-articular sodium hyaluronate in patients with reducing displaced disc of the temporomandibular joint

In this clinical trial, we examined the efficacy of intra-articular hyaluronic acid (HA) treatment in 38 patients with reducing displaced disc of the temporomandibular joint (TMJ). Subjects received two unilateral upper space injections of HA or physiological saline solution with 1 week apart. Efficacy was based on the following measurements: pain and sound intensity of the joint measured by visual analogue scale (VAS), modified Helkimo's clinical dysfunction index and the intensity of joint vibration during opening and closing the mouth measured by accelerometers. These measurements were performed before the first injection and 1 and 6 months after the last injection. In the treatment group (n=19), all measurements improved significantly at month 1 and at month 6 compared with the baseline (P < 0.01). The same measurements, in the placebo group (n=19), did not show any change, except for the pain intensity which improved at month 1 and month 6 (P < 0.05). The change in baseline measurements of all of the efficacy criteria at month 1 and at month 6 in the treatment group was significantly better compared with the change obtained with placebo at the same time intervals. This study demonstrates that intra-articular sodium hyaluronate (Orthovisc) injection into the TMJ is an effective treatment for a reducing displaced disc.     

Treatment of 'en coup de sabre' deformity with porous polyethylene implant

Linear scleroderma "en coup de saber" (LSCS) deformity is a subgroup of scleroderma characterized by unilateral atrophy and depression above the level of the eyebrow. In rare cases where it involves the whole unilateral face it can be mistaken with Parry-Romberg syndrome. Involvement of the trunk and extremities together with facial lesions has been extremely rare in the literature. We report an unusual case of linear scleroderma "en coup de sabre" where there is concomitant involvement of the ipsilateral side of the trunk and lower extremity. The patient's facial deformity is reconstructed with a polyethylene implant.     

Implant-retained auricular prosthesis

Auricular defects may result from congenital malformations, injuries from motor vehicle crashes, trauma, or tumor resections. An auricular prosthesis was fabricated for a patient who had an injury from a motor vehicle crash. Extraoral implants and bar-and-clip retention for the proper connection of the auricular prosthesis to implant were used. This prosthesis was acceptable to the patient because of excellent support, retentive abilities, and the patient's appearance.     

The in vitro effect of pulpal pressure and luting agent on tensile bond strength of complete cast crowns

STATEMENT OF PROBLEM: The degree to which pulpal pressure may affect bond strength of complete cast crowns is unknown. PURPOSE: The aim of this in vitro study was to evaluate the effect of simulated pulpal pressure on the tensile bond strength of complete cast crowns luted with 2 different cements. MATERIAL AND METHODS: Forty-eight human mandibular canine teeth were cleaned and stored in saline solution. The crowns were prepared by 1 investigator, and standardization of the preparation was accomplished by fixing a dental handpiece in a parallelometer. Uniform grooves, 0.5 mm in depth, were prepared with burs with depth guides. The complete crowns were prepared with a 0.5-mm shoulder margin. Teeth were randomly divided into 2 groups of 24 teeth each (Group I and Group II). In Group I, bonding and tensile test procedures of the teeth were carried out under simulated pulpal pressure (15 cm of saline solution). In Group II, simulated pulpal pressure was not used. The roots were removed 1 mm below the cementoenamel junction to create direct communication with the pulp chamber. The remaining pulpal tissues were carefully removed, and crowns were embedded in acrylic resin. The acrylic resin was then penetrated by a stainless steel tube that connected the pulp chamber and the barrel of a disposable plastic 5-ml syringe. The pulp chambers were filled with physiological saline solution under elevated pressure to locate the area of greatest permeability on the dentinal surface. Crowns were cast (Co-Cr alloy) with a 20-mm bar to allow testing of the bond strength. Each of the 2 groups were further divided into 2 luting cement groups of 12 each (Group I, A and B, and Group II, A and B). Group IA/IIA and Group IB/IIB specimens were luted with a polycarboxylate luting cement (Poly-F Plus) and an adhesive luting cement (Superbond C&B), respectively. After storage in distilled water for 24 hours, all specimens were subjected to a tensile bond test in a universal testing machine at a crosshead speed of 0.5 mm/min until failure. The maximum load at fracture (Newton) was recorded. The results were then evaluated with 2-way analysis of variance and Tukey's honestly significant difference tests (alpha=.05). RESULTS: Simulated pulpal pressure increased the bond strength of cast complete crowns cemented with an adhesive luting agent (P=.01). No significant difference was found in the bond strength of complete cast crowns cemented with polycarboxylate cement with or without pulpal pressure. Superbond C&B adhesive luting agent showed significantly higher bond strength values for Group I (388.9+/-32.7) and Group II (300.9+/-66.8), when compared with polycarboxylate cement for Group I (221.3+/-17.3) and Group II (186.8+/-38.5) (P=.001). CONCLUSION: Simulated pulpal pressure had a positive effect on the retention of complete cast crowns when cemented with Superbond C&B adhesive luting agent. Superbond C&B significantly increased the retention of crowns in either the presence or absence of pulpal pressure.     

Microleakage of endodontically treated teeth with different dowel systems

STATEMENT OF PROBLEM: Several new esthetic dowel systems are available for the restoration of endodontically treated teeth, but little is known about how effectively these dowels seal the restored teeth. PURPOSE: The purpose of this in vitro study was to compare microleakage of 3 esthetic, adhesively luted dowel systems with a conventional dowel system. MATERIAL AND METHODS: The root canals of 41 human intact single-rooted extracted teeth were prepared using a step-back technique. The teeth were randomly divided into 4 experimental groups (n=10), and 1 tooth served as a positive control. The decoronated roots were obturated with gutta-percha using lateral condensation. Roots were restored with 1 of the following dowel systems according to the manufacturer's instructions: (1) stainless steel dowels (ParaPost), (2) glass fiber dowels (Snowpost), (3) resin-supported polyethylene fiber (Ribbond) dowels, or (4) zirconia dowels (Cosmopost). Using a fluid filtration method, coronal leakage of the specimens along the dowel space and root canal restorative material was measured. Fluid movement measurements were made at 2-minute intervals for 8 minutes to measure the presence of voids existing in the obturated canals, at 1 week, 3 months, and 6 months following dowel insertion. A repeated-measures analysis of variance (ANOVA) was used to analyze logarithmic transformations of data (time and dowel material) for significant differences. The Tukey HSD test and paired 2-tailed tests were used to perform multiple comparisons (alpha=.05). RESULTS: The data indicated that the leakage values varied according to the dowel system used (P<.01). There was significant interaction between dowel systems and time of testing (P<.01). The sealing ability of zirconia dowels decreased over time (P<.01), but sealing abilities of stainless steel and resin-supported polyethylene fiber dowels remained constant (P>.05). The sealing ability of glass fiber dowels increased at 3 months (P=.032) and remained constant over the next 3 months (P=.758). Statistically, resin-supported polyethylene fiber and glass fiber dowels showed the lowest coronal leakage when compared with stainless steel and zirconia dowels at all time periods (P<.01). There were no significant differences between resin-supported polyethylene fiber and glass fiber dowels at any time period. The initial leakage measurement in zirconia dowel and stainless steel dowels were similar (P=.914), but became significantly different at 3 and 6 months (P<.01). CONCLUSION: Resin-supported polyethylene fiber dowels and glass fiber dowels tested exhibited less microleakage compared to zirconia dowel systems. The latter system should be further evaluated because of its unacceptable level of leakage.     

Fabrication of implant-assisted restorations utilizing functional impression techniques: case reports

This article describes the fabrication of implant-supported overdentures and removable partial dentures attached to anterior fixed partial dentures utilizing impression techniques to transfer the position of implants and record soft tissue areas in a functional state.     

The effect of simulated intrapulpal pressure on bond strength to enamel and dentine

The purpose of this study was to evaluate the effect of simulated intrapulpal pressure on the shear bond strength (SBS) of a self-etching bonding system (Clearfil Liner Bond II) to both enamel and dentine surfaces. Forty-two caries-free human molar teeth were randomly assigned to two equal groups (n=21). One group of 21 teeth was connected to a special pulpal pressure machine, which is developed to simulate in vivo conditions. The buccal and lingual surfaces of the teeth were prepared with a diamond wheel to create flat dentine and enamel surfaces. A self-etching bonding system was then applied under pulpal pressure and 2.5 mm diameter composite cylinders were bonded to the prepared surfaces. The samples were then stored in distilled water at room temperature for 24 h under pulpal pressure before SBS was tested. The second restored group was used as a control and the teeth were not connected to the pulpal pressure apparatus during material application and test procedures. They were stored for 24 h in distilled water at room temperature before the SBS test. Fracture analysis of the enamel and dentinal surfaces was performed using a stereomicroscope. Shear bond strength values to dentine was significantly reduced with pulpal pressure (P < 0.001). However, in the enamel, SBS was increased (P < 0.001). In the control group, the SBS values to dentine and enamel did not show any significant difference (P > 0.05). Based on these results, it can be concluded that further analysis of enamel histology and bonding mechanisms are needed.