A clinical evaluation of fixed partial denture impressions

STATEMENT OF PROBLEM: Providing the dental laboratory with an accurate replication of the hard and soft tissue of a patient is important. Therefore, it is essential to examine whether clinicians critically evaluate impressions routinely before sending them to the laboratory. PURPOSE: This study evaluated the quality of impressions sent to commercial laboratories for the fabrication of fixed partial dentures (FPD) by describing the frequency of clinically detectable errors and by analyzing correlations between the various factors involved. MATERIAL AND METHODS: A total of 193 FPD impressions were evaluated, immediately after arrival at 11 dental laboratories, by 3 calibrated examiners. The impression technique and material used, tray type, and number of prepared units were recorded for each impression. Data relating to errors and faults, including defects in material polymerization, retention to tray, tissue contact by tray, crucial areas beyond tray borders, heavy-bodied material exposure through the wash material (for double-step impressions), inadequate union of materials, retraction cords embedded in impressions, and air bubbles, voids, or tears along the margin were also documented. The data were analyzed with the Pearson chi-square test (alpha = .05). RESULTS: Of the impressions, 89.1% had 1 or more observable errors. Significant correlations were found between material type and voids or tears at the finish line (Rv = 0.17, P < .025) and between material type and polymerization problems (Rv = 0.223, P < .004). CONCLUSIONS: Within the limitations of this study, impressions made with polyethers had the most detectable errors, followed by condensation-type silicones. The high frequency of detectable errors found in impressions sent for FPD fabrication is of concern.     

Voids and interlayer gaps in Class 1 posterior composite restorations: a comparison between a microlayer and a 2-layer technique.

OBJECTIVE: The main objective was to compare the presence of interlayer gaps between 2 hybrid composites placed using a microlayer and a 2-layer technique. METHOD AND MATERIALS: Standardized Class 1 cavities were prepared in 40 extracted posterior teeth. Two resin composite materials were used. The control group, group A, consisted of samples of the materials extruded out of the manufacturers' syringes. Group B consisted of 10 teeth restored using 2 layers per restoration. Group C consisted of 30 teeth restored using 6 microlayers per restoration. A scanning electron microscope was used to detect voids in the samples. RESULTS: Round, well-defined voids were found in 85% to 100% of the samples within the bulks of the resin composite materials only. A statistically significant relationship between the type of composite and presence of bubbles (Fisher exact test, P = .04) was found among the 2-layer technique group. No statistically significant difference (Fisher exact test, P = .48) was found among the microlayer technique group. Irregular interlayer gaps were found in 5% to 15% of specimens within areas between bulks of composite, as detected by an electron microscope based on the different densities of the bulks of composite and the interlayer areas. No such statistically significant relationship was found (Fisher exact, P = .62) among the study groups. CONCLUSIONS: Voids are routinely found in bulks of composite materials. Higher incidences of interlayer gaps in the 2-layer samples suggest that the use of a microlayering technique may result in fewer gaps.     

Techniques for immediate restoration of teeth following root canal therapy

It is incumbent upon the dentist to restore the form and function of endodontically treated teeth. Different approaches and materials are described in the literature for restoring the missing tooth structure, either with a cast post and core or immediately with a chair-side post and core system. This article briefly reviews the available data regarding the microbiological, prosthetic, mechanical, and periodontal aspects while emphasizing the immediate approach using amalgam, composite and glass ionomer materials. The factors affecting retention of the post are presented to guide the clinician in selecting a suitable post and core system in preserving optimal root structure to prevent root fracture. Two clinical cases are presented in which tooth structure was restored using two techniques: in one, a provisional acrylic resin shell was used to house a dowel coronal-radicular amalgam core material, the other used a copper band for a composite post and core system. Both cases emphasize the ease of production and the short chair-time in the stages of crown fabrication.     

Incomplete mobilization of the maxilla resulting in failed maxillary distraction: a case report

Maxillary distraction osteogenesis has become an accepted alternative method in the treatment of patients with severe maxillary hypoplasia in craniofacial syndromes and cleft-related deformities. Insufficient distraction, undesirable soft tissue changes, and occurrence of defective distraction vectors are among the potential complications of intraoral maxillary distraction osteogenesis. A 2-stage procedure combining maxillary advancement by distraction technique with genioplasty and mandibular setback surgery was planned to correct jaw deformities in a 22-year-old patient with severe maxillary retrusion, mandibular prognathism, and excessive lower facial height. In the first stage, osteotomies were performed and maxilla was lightly mobilized after down-fracture. Distractors were placed to the maxilla intraorally. During activation period, the maxilla rotated in a clockwise direction, producing a discrepancy between the planned and the actual vectors. Complete distraction was unsatisfactory and the complication was due to surgical technique. This case report presents the failure of maxillary distraction due to incomplete mobilization of the maxilla. Treatment of the case was achieved by the conventional osteotomy techniques at final operation. The maxilla was successfully advanced to the desired position producing good occlusion and an improved facial profile.     

Smoking and complications of endosseous dental implants

BACKGROUND: The purpose of this study was to compare the incidence of the complications and survival rate related to dental implants among smokers and non-smokers, and to evaluate the influence of smoking by analyzing data of 959 implants placed in 261 patients during the years 1995 to 1998. METHODS: Patients were divided into 3 groups: non-smokers, mild smokers (up to 10 cigarettes per day) and heavy smokers (more than 10 cigarettes per day); smokers were divided into 2 subgroups according to duration of smoking (less or more than 10 years). Complications included minor (spontaneous implant exposure), major (spontaneous implant exposure requiring surgical intervention), and implant failure. The influence of smoking was analyzed for the type of implant cover screw and immediate versus late implantation. RESULTS: The overall failure rate was 2% for non-smokers and 4% for all smokers. Minor and major complications were found in higher percentages (46%) in the smoking groups than in the non-smoking group (31%). A significantly higher incidence of complications was found among smokers who received dental implants with high cover screws (63%) compared to those who received dental implants with flat cover screws (27%). CONCLUSIONS: This study establishes a relationship between implant complications and smoking, implant type (external or internal hex), and time of implantation as significant factors. A higher incidence of complications was found in the smoking group, especially in implants that had a high cover screw. Most complications will not lead to failures. Immediate implants failed less frequently than non-immediate implants. Limiting or reducing smoking habits will decrease complications of endosseous dental implants.     

Neurological complication of non Hodgkin lymphoma in childhood: experience from a single center in Turkey

Purpose

Lymphomas are the third most common childhood malignant disease after leukemia and central nervous system (CNS) tumors. Early diagnosis of these complications will reduce mortality and morbidity. In this study we aimed to review the neurological complications of childhood non Hodgkin Lymphoma (NHL).

Patients and methods

Forty four children with NHL between 2006 and 2012 were investigated retrospectively and 14 cases with neurological complications were identified.

Results

The most common symptom was alteration of the consciousness (10 patients, 71.4 %) followed by convulsion (5 patients, 35.7 %), and hallucination (4 patients, 28.5 %); headache, eye pain, neurogenic bladder, speech disability and facial paralysis, and hemiplegia, were less common and each of them was seen in 1 (7.1 %) of the patients. The neurological complications were mostly seen in children with precursor T lymphoblastic lymphoma followed by anaplastic large cell lymphoma. The complications were secondary to medications (Eight patients) infection (two patients); CNS relapse (two patients); or CNS involvement of the primary disease (two patients). Chemotherapy-related neurologic complications were secondary to intrathecal methotrexate, l-asparaginase, vincristine, and ifosfamide

Conclusion

Advanced disease and PTLL subtype can be suggested as predictors of neurological complication. The survival rates of neurological complications are fairly good unless it is secondary to involvement of the primary disease. In patients with drug-induced neurological complications, the treatment can be safely re-administered after controlling the neurological complications. Therefore, clinicians managing children with NHL must be informative about neurological complications.     

Intracranial hemorrhage in infants as a serious,and preventable consequence of late form of vitamin K deficiency: a selfie picture of Turkey,strategies for tomorrow

Purpose

Vitamin K deficiency bleeding is one of the most common causes of acquired hemostatic disorder in early infancy. Although vitamin K is practiced routinely after every birth in Turkey, children with type of vitamin K deficiency bleedings (L-VKDB) can be encountered. We aimed to evaluate the clinical features of the children with L-VKDB reported from Turkey.

Methods

Between 1995 and 2013, 48 studies reporting 534 children with L-VKDB were evaluated in this study.

Results

Of the 534 reported children (178 girls, 356 boys), 486 (91 %) were extremely breastfed. The most common bleeding sites were intracranial hemorrhage, gastrointestinal, and umbilical in 414 (77.4 %), 33 (6.2 %), and 33 (6.2 %) children, respectively, and 35 (6.6 %) children had been diagnosed incidentally without any bleeding. The etiology of 399 (74.7 %) children were classified as idiopathic, whereas 135 (25.3 %) were secondary. Intramuscular vitamin K was administered in 248 (46.4 %), not administered in 228 (42.7 %), and the administration of vitamin K were not determined in 58 (10.9 %) children. The outcomes of Turkish cohort showed that 111 (20.8) children died, 257 (48.1 %) cases developed neurologic deficit (mainly epilepsy and psychomotor retardation), and only 166 (31.1 %) patients recovered without squeal.

Conclusions

The compliance of prophylactic measures in Turkey does not seem to be satisfactory. As a further measure of tomorrow, we vigorously emphasize that a national surveillance program may be initiated. An additional intramuscular dose or oral supplementation of vitamin K especially for exclusively breast-fed infants may reduce this catastrophic problem in our country.     

Fetal intracranial hemorrhage related to maternal autoimmune thrombocytopenic purpura

Background

Maternal autoimmune thrombocytopenic purpura (AITP) can cause fetal intracranial hemorrhage.

Case report

A 19-year-old primigravida was referred to our institution for prenatally detected ventriculomegaly at 30th week of gestation. Her personal and family histories were unremarkable. Her platelet count was 54?×?109/L. Fetal neurosonography showed intraparenchymal hemorrhage. AITP was diagnosed in the mother and platelet count decreased at 34?×?109/L. Patient was treated with methylprednisolone and intravenous immunoglobulin. She delivered a 2,340-g infant at 37 weeks with elective cesarean section. The platelet count of the newborn was 181?×?109/L and coagulation tests were normal. No antiplatelet specific antibodies were detected in cord blood. Postnatal MRI evaluation confirmed grade IV intracranial hemorrhage. The newborn baby has suffered from mild spasticity and seizures.

Conclusions

Clinicians must be vigilant about the catastrophic fetal complications of maternal AITP; a close follow-up with a multidisciplinary cooperation between obstetricians, hematologists, and neonatologists must be warranted.