Predictors of specific phobia in children with Williams syndrome.

BACKGROUND: Specific phobia (SP) is the most common anxiety disorder among children with Williams syndrome (WS); prevalence rates derived from Diagnostic and Statistical Manual of Mental Disorders-based diagnostic interviews range from 37% to 56%. We evaluated the effects of gender, age, intellectual abilities and/or behaviour regulation difficulties on the likelihood that a child with WS would be diagnosed with SP. METHODS: A total of 194 6-17 year-olds with WS were evaluated. To best characterise the relations between the predictors and the probability of a SP diagnosis, we explored not only possible linear effects but also curvilinear effects. RESULTS: No gender differences were detected. As age increased, the likelihood of receiving a SP diagnosis decreased. As IQ increased, the probability of receiving a SP diagnosis also decreased. Behaviour regulation difficulties were the strongest predictor of a positive diagnosis. A quadratic relation was detected: The probability of receiving a SP diagnosis gradually rose as behaviour regulation difficulties increased. However, once behaviour regulation difficulties approached the clinical range, the probability of receiving a SP diagnosis asymptoted at a high level. CONCLUSION: Children with behaviour regulation difficulties in or just below the clinical range were at the greatest risk of developing SP. These findings highlight the value of large samples and the importance of evaluating for nonlinear effects to provide accurate model specification when characterising relations among a dependent variable and possible predictors.

The use of dental amalgam in pediatric dentistry: review of the literature.

Dental amalgam is widely used as a restorative material even though it is not esthetic and there has been extensive anti-amalgam rhetoric. Although other materials have improved greatly, amalgam has the proven safety record and best cost-to-benefit ratio. Clinical evidence indicates that, in the posterior permanent dentition--where esthetics is not a primary concern--the small, minimally prepared, amalgam restoration, with its margins and any caries-susceptible fissures sealed with resin fissure sealant, is the restoration with the best survival. Amalgam also remains the best direct restorative option when larger restorations are required. In the primary dentition, the data indicates that resin-based composite and resin-modified glass-ionomer serve very well.

The performance of bonded vs. pin-retained complex amalgam restorations: a five-year clinical evaluation.

BACKGROUND: The authors compared the clinical performance of complex amalgam restorations, replacing at least one cusp--retained either mechanically with self-threading pins or bonded--with a filled, 4-methacryloxyethyl trimellitate anhydride, or 4-META-based resin designed for amalgam bonding. METHODS: The authors placed 60 amalgam restorations (28 pin-retained and 32 bonded), each restoration replacing at least one cusp. They used self-threading stainless steel pins in the pin-retained group and a filled, 4-META-based bonding resin in the bonded group. For both groups, the authors left in place any retention form remaining after removal of an old restoration but did not enhance it. RESULTS: At four years, six restorations had failed. At five years, of the 40 restorations available for evaluation, three had failed, for a total of nine failed restorations; seven of those were pin-retained and two were bonded. Using the Fisher exact test to compare the groups at five years, the authors found no significant difference in failure rate, marginal adaptation, marginal discoloration, secondary caries, tooth sensitivity or tooth vitality. CONCLUSIONS: At five years, there was no difference in the performance of pin-retained amalgam restorations and bonded amalgam restorations. This study will be continued for at least a sixth year. CLINICAL IMPLICATIONS: Bonding with a filled, 4-META-based bonding resin appears to be a satisfactory method of retaining large amalgam restorations replacing cusps.

Neonatal skin care: clinical outcomes of the AWHONN/NANN evidence-based clinical practice guideline. Association of Women's Health, Obstetric and Neonatal Nurses and the National Association of Neonatal Nurses.

OBJECTIVE: To test the effectiveness of an evidence-based clinical practice guideline for neonatal skin care on selected clinical outcomes for newborns in neonatal intensive-care units (NICU), special-care units (SCU), and well-baby nurseries. DESIGN: Prospective evaluation of the collaborative neonatal skin care research-based practice project of the Association of Women's Health, Obstetric and Neonatal Nurses and the National Association of Neonatal Nurses. SETTING: NICU and well-baby units in 51 hospitals located throughout the United States. PARTICIPANTS: Member site coordinators (N = 51) and the neonates (N= 2,820) observed during both the pre- and postimplementation phases of the project. METHOD: Site coordinators received specialized education in neonatal skin care and implemented an evidence-based clinical practice guideline addressing 10 aspects of neonatal skin care. Baseline observations of skin condition, care practices, and environment of newly admitted neonates were collected by site coordinators. Postimplementation observations were then completed. MAIN OUTCOME MEASURES: Skin condition was assessed with the Neonatal Skin Condition Score (NSCS), which ranges from a score of three (best condition) to a score of nine (worst condition), based on dryness, erythema, and skin breakdown. Changes in frequency of selected skin care practices were used to assess the effectiveness and feasibility of using the practice guideline in everyday clinical practice. Aspects of the care environment with potential effect on skin integrity were monitored to determine risk factors. RESULTS: Fifty-one site coordinators made 11,468 systematic assessments of 2,464 NICU and SCU newborns and 356 well newborns. Baseline skin scores were better in well newborns compared with premature newborns. After implementation of the guideline, skin condition was improved, as reflected by less visible dryness, redness, and skin breakdown in both the NICU/SCU and well newborns. The guideline was integrated into care, as evidenced by increased use of emollients, particularly with premature infants, and decreased frequency of bathing. A relationship was shown between selected aspects of the environment and alterations in skin integrity. CONCLUSIONS: Use of the AWHONN/NANN Neonatal Skin Care Research-Based Clinical Practice Guideline was successfully implemented at 51 sites, and effectiveness was demonstrated by changed care practices and improved skin condition in premature and full-term newborns. The results of this project support a wider dissemination of the project's practice guideline for neonatal skin care.

Clinical evaluation and microstructural analysis of a direct placement gallium restorative alloy.

OBJECTIVES: The objective of this study was to assess the clinical performance of a direct placement gallium alloy sealed with an established dentine adhesive system. In addition, microanalysis of a few gallium restorations that failed in clinical service was performed. Clinical factors such as pulpal sensitivity, fracture of the restoration and of the tooth, marginal deterioration, and tarnish were assessed. METHODS: Sixty-five restorations of Galloy and 62 of Tytin (49 and 51 Class II restorations, respectively) were placed according to a predetermined scheme for randomisation in 37 patients by two operators using rubber dam isolation. For the Galloy restorations, the enamel and dentine were etched, and then sealed with PAAMA 2 dentine adhesive according to the manufacturer's instructions. After carving, PAAMA 2 was applied to the Galloy and light-cured. Cavity preparations for Tytin received no adhesive sealer. All restorations were polished at least 24 h post-operatively. Microstructural analysis of retrieved fragments of failed restorations was conducted using electron probe microanalysis. RESULTS: At 1 year, only one Tytin restoration was found to have failed due to an isthmus fracture. The remaining restorations of Tytin were intact with no reported sensitivity. Of the 65 Galloy restorations placed, 28 had to be removed, including restorations in teeth, which were symptomatic, non-vital and/or fractured, and teeth with fractured restorations. Tarnish was present on many of the Galloy restorations. Retrieved fragments of failed Galloy restorations exhibited a dark surface at the pulpal wall interface and small cracks were observed in that surface. Internal cracks and extensive corrosion was observed using the microprobe. Gallium oxides and chlorides were identified as the predominant corrosion products. CONCLUSIONS: The gallium alloy, Galloy, sealed with PAAMA 2 dentine adhesive system demonstrated a high clinical failure rate.

Long-term corrosion of a Ga-containing restorative material.

OBJECTIVE: The aim was to simulate and characterize the long-term corrosion of a Ga-containing alloy (Galloy, SDI). METHODS: To induce corrosion, cylindrical specimens, 8 x 4 mm, of the material were subject to potentiostatic polarization at -0.1 V (SCE) in a phosphated buffered saline (PBS) solution at 20 degrees C for d. The current-time transients during polarization were recorded and the corresponding anodic charge, Q, was calculated. Parallel potentiostatic corrosion tests in a Cl-free PBS solution were also conducted to demonstrate the significance of the Cl- ion in corrosion. In addition, potentiodynamic anodic polarization tests were performed to characterize the overall corrosion behavior of the alloy in both electrolytes. The external and internal corroded layers, formed during potentiostatic corrosion in PBS, were measured by optical microscopy. SEM and EDXA were used to characterize the morphology and composition of the potentiostatically polarized surfaces. RESULTS: Galloy was passive in Cl-free PBS. The Cl- ion in PBS destroyed passivity and initiated a "dissolution-precipitation" type reaction during potentiostatic corrosion. The latter led to circumferential internal corrosion and growth of a layer of external corrosion products. The thickness of the internal and external corrosion layers was 0.77 +/- 0.07 and 0.86 +/- 0.37 mm, respectively. The Q value (89.3 +/- 13.7 C/cm2) in PBS was about two orders of magnitude higher than that (0.66 +/- 0.24 C/cm2) in Cl-free PBS. The corrosion products contained Sn, Ga, In, Cu, O and Cl. SIGNIFICANCE: Massive internal and external corrosion in a Cl-containing medium as in saliva, accumulation of corrosion products at the cavity wall, and the consequent stress build-up contribute to post-operative pain, tooth straining, marginal breakdown and fractured teeth reported with the clinical use of Galloy.

Operative Dentistry for the new millennium: a problem specific approach to operative dentistry.

This paper presents an alternate view of current preclinical education in Operative Dentistry and suggests a course that uses a cause and appropriate response action rather than the traditional material specific cavity preparation. This approach considers caries as a disease, could foster a better understanding of prevention and its application in maintaining teeth for a lifetime for the patient, and encourage critical thinking for both student and faculty.

Network structure and hospital financial performance in New York State: 1991-1995.

As networks have proliferated, questions have arisen regarding which structure is optimal. To obtain an answer from the hospital perspective, the authors conducted a survey of New York State hospitals to determine how network integration, complexity, and financial risk sharing relate to measures of financial performance during the period of 1991-1995. Of the 64 hospitals indicating a network affiliation by 1995, 67.2 percent listed some network risk-sharing activity. The least integrated networks were associated with the smallest improvements in throughput, and the most complex were associated with the largest negative changes in operating margins. During the first 2 years of network membership, hospitals joining risk-sharing networks experienced operating margin gains averaging 12 percentage points higher than hospitals joining networks without risk sharing; however, this difference dissipated in later years. Networks with higher levels of integration, lower levels of complexity, and which involve some risk-sharing between affiliates are most likely to experience improved hospital financial performance during the network's initial years.

Exploring instructional quality indicators in ambulatory medical settings: an ethnographic approach.

BACKGROUND AND OBJECTIVES: As medical education moves to community settings, the quality of learning is influenced by differences in the practice environment, organization, resources, patient case mix, and demographics. This ethnographic study identified experiences and processes that influence student learning in community-based practice settings. METHODS: Trained field researchers conducted participant observation in eight community teaching sites. Data were analyzed using a qualitative, grounded theory approach. RESULTS: Three dominant themes emerged: 1) the preceptor's role in situating learning opportunities, 2) the learner's role in transforming experience into learning, and 3) the practice organization as a classroom setting. The findings highlight the importance of exploiting learning opportunities and the contributions of other medical staff and patients in facilitating unique learning experiences. CONCLUSIONS: This research suggests the need to move beyond the typical student ratings of teacher effectiveness to consider and assess additional important factors and processes that affect instructional quality.

Photoelastic assessment of the expansion of direct-placement gallium restorative alloys.

OBJECTIVE: The purpose of this study was to assess, via a photoelastic resin, the expansion of gallium restorative alloys under conditions similar to those found in the clinical situation. METHOD AND MATERIALS: Two gallium alloys, Galloy and Gallium GF II, were tested, along with a high-copper amalgam, Dispersalloy, and a low-copper alloy, New True Dentalloy. The gallium alloys were tested as (1) uncontaminated, (2) contaminated with water, Ringer's solution, or a cell culture medium, and (3) immersed in these fluids at times ranging from 5 minutes to 3 days. The gallium and amalgam alloys were condensed in a hole drilled in a block of photoelastic resin and observed for 3 months. The amount of stress was recorded on color slides taken through polarized light at regular intervals. The photographs of the color bifringen stress patterns at 1 and 3 months were ranked by two independent evaluators for least to greatest observed stress. RESULTS: Dispersalloy had the least expansion, followed by uncontaminated Galloy and Galloy contaminated with water. Next came Galloy contaminated with cell culture medium, Galloy contaminated with Ringer's solution, contaminated New True Dentalloy, and Gallium GF II. The last group was Gallium GF II contaminated with any of the three solutions. Both gallium alloys immersed in the three fluids showed a strong edge effect, and by 6 weeks many of the gallium alloys had extruded from the mold. CONCLUSION: These results corroborate the findings of some clinical studies that have shown that these gallium alloys can potentially cause catastrophic failures.

Direct-placement gallium restorative alloy: a 3-year clinical evaluation.

OBJECTIVE: A pilot clinical study on a direct-placement gallium restorative alloy was initiated with nine patients who signed a consent form. METHOD AND MATERIALS: Thirty Class I restorations were placed and assessed over a 3-year period. The cavity preparations and surface of the restorations were sealed to prevent oral fluids from contacting the gallium alloy during placement and early setting of the gallium restorative material. RESULTS: The initial 18-month clinical results were encouraging. But at 21 months, one tooth had fractured, and within another year two molars were diagnosed with cracked-tooth syndrome (incomplete tooth fracture). These three fractured teeth were restored with amalgam and are symptomless at this time. There was little fracture at the margins of the gallium restorative, but tarnish and a rough surface were noted on many of the gallium restorations. The direct-placement gallium restorative alloys must be further assessed in the laboratory to correct dimensional instability. CONCLUSION: Results suggested that Galloy, used with either of two sealing resins, is not a suitable restorative material.

A measure of medical instructional quality in ambulatory settings: the MedIQ.

BACKGROUND AND OBJECTIVES: Concerns exist about the quality of medical student training outside the academic medical center. Yet, measures of this quality are lacking. This study introduces an instrument to measure instructional activities in primary care settings, based on a learner-centered model. The study also examines the instrument's ability to predict specific learner outcomes. METHODS: The MedIQ is a 25-item instrument designed to assess preceptor activities, environmental interactions, learning opportunities, and learner involvement in patient care. The MedIQ was administered in third-year generalist clerkships at one medical school, and the results were compared to extant measures of precepting effectiveness, student grades, specialty choice, and National Board of Medical Examiners scores. RESULTS: The results revealed strong reliability for all scales, moderate construct validity, and weak criterion-related validity. Additionally, some scores predicted specialty choice. CONCLUSION: The MedIQ is a promising measure of instructional quality in ambulatory medical settings.

Managed care in rural markets: availability and enrollment.

The objective of this research was to test the hypothesis that urban-rural differences in managed care availability and enrollment are primarily due to differences in population socioeconomic and health system characteristics rather than geographic location, population size, or density. These two groups of variables were entered into a regression equation to determine which group could best account for the variance in managed care availability and enrollment. In general, the results of these analyses indicated that socioeconomic and health system characteristics did a much better job of explaining differences in managed care availability and enrollment. Therefore, focusing on factors such as adjacency to metropolitan areas or population size or density in making managed care policy decisions may be less productive than focusing on the socioeconomic and health system characteristics of an area.

Marshall H. Webb and extension for prevention: a literature review.

Dr Marshall Webb (1844-1883), author, lecturer, debater, clinician, inventor, and dentist extraordinaire, was a decade ahead of others in putting forth a concept of "extension for prevention." One hundred twenty years ago, he was one of the best known, most advanced, and highly regarded dentists in the world. His pioneering work in cardiology, preventive dentistry, ethics, and prevention of recurrent decay raised the standards of what we call operative or conservative dentistry, but he is almost unknown now. However, his concept of conservative tooth preparation could be applied today.

Psychological and medical effects of mercury intake from dental amalgam. A status report for the American Journal of Dentistry.

Studies examining health consequences of the release of mercury from dental amalgams have concluded that there is insufficient mercury released from these restorations to cause a medical problem. Although the mercury vapor generated during removal of amalgams will cause a transient increase in the patient's mercury level in tissue fluids, biochemical assays have demonstrated that the increase is too small to have a negative influence on organ systems. This is true even when patients have all their amalgams removed in a single session. Nevertheless, over the past decade, the release of mercury from dental amalgam has been frequently blamed for a variety of health complaints. A number of sensationalized media reports regarding the mercury issue have no doubt contributed to the public concern that has been aroused. Consequently, patients may present at the dentist's office, either self-diagnosed or looking for a cause implicating mercury. In actuality, these patients may have symptoms of either medical problems or psychological disorders such as depression or anxiety. Unfortunately, the incorrect diagnosis may not only mislead, but actually place the patient in a dangerous situation. Two well-controlled studies have indicated that (1) 89% of the patients with self-reported "amalgam illness" had psychogenic disorders, whereas only 6% of the matched-pair manifested symptoms of these psychological disorders; and (2) these alleged "amalgam illness" patients had preneurotic reactive/defensive mechanisms that did not allow them to recognize aggressive and threatening situations which the control group would quickly and readily regard as potentially difficult to manage. Other studies involving psychological assessment seem to confirm that dental therapy (removal of amalgams) for people with alleged "amalgam illness" may, at best, provide a "placebo effect".

Expansion of contaminated amalgams assessed by photoelastic resin.

OBJECTIVE: Eight amalgam alloys, 6 high-copper and 2 low-copper, were assessed for expansion via photoelastic resin. METHOD AND MATERIALS: The photoelastic resin sheet was sectioned into 20 x 25-mm blocks, and two 4 x 8-mm holes were drilled into the resin. The amalgam alloys were hand condensed into the prepared holes. Test conditions for each alloy were (1) uncontaminated, (2) contaminated with 5 microL of Ringer's solution, and (3) contaminated with 5 microL of cell culture medium. RESULTS: Contaminated high-copper amalgam alloys may exhibit expansion to varying degrees but do not show the classic delayed expansion. One spherical, nonzinc high-copper alloy showed no expansion, whether it was uncontaminated or contaminated, and 3 high-copper alloys with different amounts of zinc (0% to 1%) showed slight expansion when contaminated. One low-copper alloy displayed delayed expansion; within 17 days after initial expansion in the photoelastic resin, it had exceeded the greatest stress observed in any contaminated, high-copper zinc-containing alloy at 3 months. CONCLUSION: Contamination of dental amalgam is to be avoided, but a zinc-containing high-copper amalgam will not exhibit classic delayed expansion even if contaminated.

Amalgam at the new millennium.

Dental amalgam has served as an excellent and versatile restorative material for many years, despite periods of controversy. The authors review its history, summarize the evidence in regard to its performance and offer predictions for the future of this material. For the present, amalgam should remain the material of choice for economical direct restoration of posterior teeth. When esthetic concerns are paramount, tooth-colored materials, placed meticulously, can provide an acceptable alternative.

Extension for prevention: is it relevant today?

Extension for prevention has been an integral part of dentistry for over 100 years. Because this concept advocated the removal of sound tooth structure, it was not totally accepted at the turn of the century. The advent of the gold casting catapulted extension for prevention into general acceptance. In 1883, Webb presented a concept of "prevention of extension of decay". This concept advocated a proximal cavity preparation extending toward the buccal and lingual aspects of the tooth so that contact with adjacent teeth would not be at the margins. The separation of the margins, along with proper restoration contours, was thought to promote natural cleansing of the embrasures with saliva and fluids in the diet. GV Black's 1891 idea of "extension for prevention" was to provide extension of the preparation to the facial and lingual line angles in order to bring about "self-cleansing" margins via food excursion. Black's concept also included extending preparations through fissures to allow cavosurface margins to be on non-fissured enamel. Black integrated the extension of the proximal margins with his concept of an occlusal isthmus for a Class II amalgam preparation one-third the faciolingual width of the occlusal surface. Challenges to this concept of extension for prevention were immediate; and, by the 1950's, narrower, more conservative preparations were seen by a few as being more effective in preserving teeth. Not only occlusal width was reassessed, but the need to routinely extend proximal margins to the buccal and lingual line angles was also questioned. By the mid-1960's and early 1970's a more conservative approach to amalgam preparation was advocated and was being taught in some dental schools. Today, a standardized outline form should not be used or taught as a principle of cavity preparation. In areas where fissure caries has necessitated a preparation extending into dentin, a composite resin or dental amalgam restoration should be placed, and a fissure sealant should be used to protect remaining susceptible fissures from carious attack. This current form of the concept of extension for prevention, which is supported by clinical research, preserves sound tooth structure that, using outdated concepts, would have been cut away. Placing proximal margins in sound tooth structure that just clears an adjacent tooth is also strongly advocated. Sound enamel margins in certain areas may occasionally be left in contact with adjacent teeth for amalgam preparations. For Class II preparations for composite resin, facial or lingual proximal bevels will usually suffice to separate the margins from the adjacent tooth to allow finishing and polishing at the margins. Preventing unnecessary extension and allowing sounder tooth structure to remain is one important aspect of helping patients to maintain their teeth for their lifetimes.