Relaxation modulus of denture base resin reinforced with woven glass fibers

This study examined the reinforcing effect of woven glass fibers on the relaxation modulus by three-point loading of denture base resin. Three sandwich-type flexure test specimens polymerized by heating were used, all 3 mm thick: glass fibers in compression (U type); glass fibers in the center (C type); and glass fibers in tension (L type). Unreinforced specimens (ACR) were produced as a control. The relaxation modulus after 8 sec from the start of stress (Er(8)) was calculated from stress relaxation curves. In the glassy state, the Er(8)s of the U and L types were greater than those of the ACR and C types. In the rubbery state (plateau region), the Er(8)s of the U and L types were greater than those of the ACR and C types. The woven glass fibers added to the U and L type specimens increased the relaxation modulus of PMMA near the oral temperature; moreover, they inhibited stress relaxation when the temperature increased.     

Mechanical properties of light-cured composite resins cured through filters that simulate enamel

The light-attenuating effects of enamel on the mechanical properties of light-cured composite resins were evaluated using simple experimental filters. Three filters were designed to simulate the light transmittance characteristics of 0.5, 1.0, and 1.5 mm thick human enamel. The Knoop hardness numbers (KHN) and the elastic modulus in transverse tests for twelve shades of three light-cured composite resins were examined. These resins were cured either using direct irradiation with a light source, or indirect irradiation through one of the filters. The attenuations of light by 0.5, 1.0, and 1.5 mm thick enamel filter were 45%, 67% and 81% in the 430 nm-550 nm wavelength region, respectively. For all materials, KHN and the elastic modulus of specimens irradiated through filters were significantly lower than those irradiated directly. The results suggest that the light-attenuating effect of enamel reduces the mechanical properties of light-cured resin, and may cause poor clinical longevity of restorations.     

Three-year prospective randomized study of incidence of posterior capsule opacification in eyes treated with topical diclofenac and betamethasone

PURPOSE: To investigate the incidence of posterior capsule opacification (PCO) in eyes treated with diclofenac sodium (DFNa) and betamethasone phosphate (BMS) ophthalmic solutions. METHODS: A total of 200 eyes with silicone intraocular lens implantation were treated with topical agents for 3 months postoperatively. Twenty-six cases of the DFNa group and 34 of the BMS group met the criteria, and the severity of PCO was evaluated after 3 years. RESULTS: The results of axial densitometry by Scheimpflug photography were 27.8 computer-compatible tapes (CCT) in the DFNa-treated group and 32.6 CCT in the BMS-treated group (p = 0.1539). Posterior capsulotomy was performed in 11.5% of the DFNa group and 17.6% of the BMS group (p = 0.8375). The photographic grading of PCO showed no difference. CONCLUSION: The incidence of PCO in eyes treated with DFNa appears to be equal to that after BMS treatment.     

Coeruleotrigeminal suppression of nociceptive sensorimotor function during inflammation in the craniofacial region of the rat

Descending action from the locus coeruleus (LC) on the trigeminal sensorimotor function was evaluated in a rat model of oral-facial inflammation. For the induction of oral-facial inflammation, mustard oil (20% solution in 20microl mineral oil) was injected into the region of the temporomandibular joint (TMJ). One week before testing, rats received bilateral lesions of the LC using a cathodal current. The electromyogram (EMG) threshold, which is the threshold intensity for the onset of EMG activity of the masseter muscle evoked by pressure on the TMJ region, was used in the present study as an indicator of the trigeminal sensorimotor function. Following mustard oil injection, in the LC-lesioned rats, EMG thresholds significantly decreased at 30min, which lasted up to 240min. In contrast, EMG thresholds in the LC-intact rats returned to the level before injection after 180min. Systemic naloxone (1.3mg/kg, i.v.) produced a further decrease of EMG thresholds in both the LC-intact and LC-lesioned rats. Under the existence of naloxone, EMG thresholds in the LC-lesioned rats were significantly lower than those of the LC-intact rats. These results suggest that oral-facial inflammation activates the coeruleotrigeminal modulating system and that an action of this system is independent of the opioid depressive mechanism.     

Daily positioning accuracy of frameless stereotactic radiation therapy with a fusion of computed tomography and linear accelerator (focal) unit: evaluation of z-axis with a z-marker

To evaluate quantitative positioning errors of frameless stereotactic radiation therapy with a fusion of computed tomography (CT) and linear accelerator unit, Z-type CT markers were attached to patients, and CT images were obtained before and after daily treatment. In 40 verification tests, geometrical errors were never more than 1 mm.     

A symptomatic child with ceftriaxone-associated biliary pseudolithiasis

A 5-year-old boy who had pneumonia was treated in a neighboring hospital. Ceftriaxone was administrated 2 g/day divided into two equal intravenous doses. After 1 week of ceftriaxone therapy, the patient developed abdominal pain. In our hospital, an abdominal sonogram showed a hyperechoic band with postacoustic shadow within the collapsed gallbladder. He was diagnosed with ceftriaxone-associated biliary pseudolithiasis, and ceftriaxone therapy was ceased. On the 8th our hospital day, he again complained of right abdominal pain after supper. A sonogram revealed high-amplitude echoes within the gallbladder neck and common bile duct. Furthermore, bile duct dilatation was observed. He was managed conservatively, after which the symptoms were resolved. On the 11th day, a sonogram showed only sludge within the gallbladder, and on the 13th day, he was discharged from our hospital. It is important for sonographers to recognize the possible occurrence of biliary pseudolithiasis in ceftriaxone-treated patients, especially when a high dose is used in children.     

Treatment of lymphangioma in children: our experience of 128 cases

Purpose

The aim of this study is to investigate the optimal treatment for lymphangioma in children by analyzing the effectiveness and complications of treatment modalities.

Methods

We reviewed 128 patients with lymphangioma treated at our institution between 1979 and 2005. Periods of treatment were divided arbitrarily into 2 groups: period I, from 1979 to 1988 (n = 53); and period II, from 1989 to 2005 (n = 75). According to radiological appearance, patients were grouped into 4 types: single cystic (SI; n = 23), macrocystic (MA; n = 11), microcystic (MI; n = 69), and cavernous (CA; n = 25).

Results

Sclerotherapy as primary treatment was performed in only 2 patients (3.8%) in period I using bleomycin but increased significantly in period II to 48 patients (64.0%) using OK-432 (P < .01). Nevertheless, primary surgical excision (69/78 patients, 88.5%) was significantly more successful than sclerotherapy (32/50, 64.0%) (P < .01). The following are the locations and types of lesions: head/neck (n = 69; SI, 11; MA, 5; MI, 42; CA, 11), trunk (n = 34; SI, 6; MA, 6; MI, 15; CA, 7), and extremities/other (n = 25; SI, 6; MI, 12; CA, 7). The effectiveness of sclerotherapy in SI, MA, MI, and CA types was 90.9%, 100%, 68.0%, and 10.0%, respectively. Seventeen patients (SI, 1; MI, 8; CA, 8) who received primary sclerotherapy required surgical excision with good outcome. Complications after primary surgical excision were more serious compared with sclerotherapy.

Conclusion

Sclerotherapy with OK-432 was not as effective as reported in the literature. We recommend OK-432 injection therapy alone for SI and MA types and surgical excision after pretreatment with OK-432 for MI and CA types.     

Laparoscopy-assisted stoma closure

PURPOSE: The aim of this study was to describe our improved technique for stoma closure, laparoscopy-assisted stoma closure (LASC). PATIENTS AND METHODS: Eleven (11) children had LASC at our institute during 2005. Their ages at LASC ranged from 4 to 23 months and their body weight ranged from 3.4 to 10.0 kg. Under general anesthesia, a 5-mm trocar was inserted through an infraumbilical, left-lower, or upper quadrant incision, and laparoscopy was used to observe the bowels, the stoma, the line of separation, and any adhesions. Externally, an incision was made around the stoma circumferentially, and a pair of mosquito forceps was inserted into the abdomen along the attachment between the stoma and the abdominal wall where no intra-abdominal adhesions were present, and the tips of the mosquito forceps were used to free the stoma along the proposed line of separation. Electrocautery was used for hemostasis and for completing the separation. After the stoma was taken down, the bowel was anastomosed and the abdomen closed in layers. RESULTS: All stomas were taken down easily without any complications in all cases. The average time for each stomal separation, from incising around the stoma until the stoma was taken down, was 23.1 minutes (range, 17-42). Injury to the abdominal wall musculature was minimal. There was 1 case of postoperative small bowel obstruction and no wound infection or incisional herniation. CONCLUSIONS: Although our experience is limited to only 11 patients, our LASC procedure appears to be an effective option for stoma closure.     

New primary management for appendiceal masses in children: laparoscopic drainage

PURPOSE: The management of appendiceal masses (AM) in children remains controversial. In this study, we evaluated primary laparoscopic drainage (PLD) for efficacy. METHODS: Eleven (11) consecutive cases of AM (mean age, 8.1 +/- 2.8 years) treated between 2000 and 2004 were the subjects for this study. All had PLD on presentation. If the appendix was seen easily seen after PLD, a laparoscopic appendectomy (LA) was also performed. RESULTS: Eight (8) patients underwent PLD alone (LD group) and 3 underwent PLD and LA (LDLA group). In the LD group, the mean operating time was 87.9 +/- 23.2 minutes, oral feeding was commenced after a mean of 2.3 +/- 0.8 days, patients became afebrile within 4.3 +/- 3.1 days, intravenous antibiotics were ceased after 5.3 +/- 3.1 days, C-reactive protein normalized within 13.6 +/- 4.2 days, drains were removed within 4.0 +/- 1.3 days, and hospital stay ranged from 7 to 15 days. There were no intra- or postoperative complications related to the PLD procedure. Interval LA was performed 6.8 +/- 5.8 months after PLD in 6 of 8 LD group patients and was not performed in the remaining 2 owing to parental refusal. In the LDLA group, operating time ranged from 125 to 150 minutes, and oral feeding commenced 4, 5, and 5 days after LA, respectively. One (1) patient developed an adhesive bowel obstruction after LA, which resolved with conservative therapy; in the remaining 2, there were no complications. All 11 patients are well after a mean follow-up period of 3.7 +/- 1.0 years. A histologic examination of the excised appendices showed mild to severe inflammation. CONCLUSIONS: We recommend that PLD be adopted for the primary management of appendiceal masses, as it would appear to be simple, safe, and effective.