Abutment Material Effect on Peri-implant Soft Tissue Color and Perceived Esthetics.

PURPOSE: The purpose of this study was to evaluate the effect of implant abutment material on peri-implant soft tissue color using intraoral spectrophotometric analysis and to compare the clinical outcomes with patient and clinician perception and satisfaction. MATERIALS AND METHODS: Thirty patients and four prosthodontic faculty members participated. Abutments were zirconia, gold-hued titanium, and titanium. Peri-implant mucosa color of a single anterior implant restoration was compared to the patient's control tooth. Spectrophotometric analysis using SpectroShadeTM Micro data determined the color difference (ΔE, ΔL*, Δa*, Δb*) between the midfacial peri-implant soft tissue for each abutment material and the marginal gingiva of the control tooth. Color difference values of the abutment groups were compared using ANOVA (α = 0.05). Patient and clinician satisfaction surveys were also conducted using a color-correcting light source. The results of each patient and clinician survey question were compared using chi-square analysis (α = 0.05). Pearson correlation analyses identified the relationship between the total color difference (ΔE) and the patient/clinician perception and satisfaction, as well as between ΔE and tissue thickness. RESULTS: Zirconia abutments displayed significantly smaller spectrophotometric gingival color difference (ΔE) compared to titanium and gold-hued titanium abutments (respectively, 3.98 ± 0.99; 7.22 ± 3.31; 5.65 ± 2.11; p < 0.05). Among ΔL*, Δa*, and Δb*, only Δa* (red-green spectrum) showed significant difference between groups. There was no significant correlation between measured soft tissue thickness and ΔE, but thick gingival phenotype, determined by a probe test, demonstrated a smaller ΔE than thin phenotype (4.82 ± 1.49; 6.41 ± 3.27; p = 0.097). There was no statistical difference in patient or clinician satisfaction among abutment materials, and no correlation between ΔE and the patient and clinician satisfaction. Patient satisfaction was significantly higher than clinician, and patient-perceived differences were lower than clinicians' (p < 0.01). Clinicians' satisfaction was higher for gingival (pink) esthetics than crown (white) esthetics (p < 0.05). CONCLUSIONS: Peri-implant mucosa with zirconia abutments demonstrated significantly lower mean color difference compared to titanium or gold-hued titanium abutments as measured spectrophotometrically; however, no statistical difference in patient or clinician perception/satisfaction among abutment materials was demonstrated. Patients were significantly more satisfied than clinicians.

Association of the GGCX (CAA)16/17 repeat polymorphism with higher warfarin dose requirements in African Americans.

OBJECTIVE: Little is known about genetic contributors to higher than usual warfarin dose requirements, particularly for African Americans. This study tested the hypothesis that the γ-glutamyl carboxylase (GGCX) genotype contributes to warfarin dose requirements greater than 7.5 mg/day in an African American population. METHODS: A total of 338 African Americans on a stable dose of warfarin were enrolled. The GGCX rs10654848 (CAA)n, rs12714145 (G>A), and rs699664 (p.R325Q); VKORC1 c.-1639G>A and rs61162043; and CYP2C9*2, *3, *5, *8, *11, and rs7089580 genotypes were tested for their association with dose requirements greater than 7.5 mg/day alone and in the context of other variables known to influence dose variability. RESULTS: The GGCX rs10654848 (CAA)16 or 17 repeat occurred at a frequency of 2.6% in African Americans and was overrepresented among patients requiring greater than 7.5 mg/day versus those who required lower doses (12 vs. 3%, P=0.003; odds ratio 4.0, 95% confidence interval, 1.5-10.5). The GGCX rs10654848 genotype remained associated with high dose requirements on regression analysis including age, body size, and VKORC1 genotype. On linear regression, the GGCX rs10654848 genotype explained 2% of the overall variability in warfarin dose in African Americans. An examination of the GGCX rs10654848 genotype in warfarin-treated Caucasians revealed a (CAA)16 repeat frequency of only 0.27% (P=0.008 compared with African Americans). CONCLUSION: These data support the GGCX rs10654848 genotype as a predictor of higher than usual warfarin doses in African Americans, who have a 10-fold higher frequency of the (CAA)16/17 repeat compared with Caucasians.

Pharmacogenomics of warfarin dose requirements in Hispanics.

While Hispanics are the largest and most rapidly growing minority population in the United States, they are underrepresented in pharmacogenomic studies with warfarin. We sought to determine the combination of clinical and genetic influences of warfarin dose requirements in Hispanics. In addition, we tested the performance of published warfarin dosing algorithms derived from largely non-Hispanic cohorts in an inner-city U.S. Hispanic population. Genetic samples and clinical data were obtained from 50 Hispanics on a stable dose of warfarin. The contribution of cytochrome P450 2C9 (CYP2C9) and vitamin K epoxide reductase complex-1 (VKORC1) genotypes and clinical factors to warfarin dose requirements was determined. The correlation between the predicted dose using published algorithms and therapeutic dose was also assessed. Compared to the VKORC1-1639 GG genotype, warfarin dose requirements were 30% and 62% lower with the GA and AA genotypes, respectively (p=0.001). The combination of the VKORC1-1639G>A and CYP2C9 genotypes and clinical factors explained 56% of the inter-patient variability in warfarin dose. Warfarin dose predicted using algorithms derived from mostly non-Hispanic cohorts was significantly correlated with the therapeutic dose in our Hispanic cohort (r(2)=0.43 to 0.49; p<0.001); the predicted dose was within 1.0 mg/day of the therapeutic dose for 40% to 50% of patients. Our data suggest that factors influencing warfarin dose requirements in Hispanic Caucasians are similar to those previously described in European Caucasians and that dosing algorithms derived from non-Hispanic Caucasian cohorts are applicable to Hispanics living in the U.S.

Effect of repeated screw joint closing and opening cycles on implant prosthetic screw reverse torque and implant and screw thread morphology.

STATEMENT OF PROBLEM: Clinicians must know if a new screw can predictably increase reverse torque after multiple screw insertion cycles. PURPOSE: The purpose of this study was (1) to compare the effect of multiple implant prosthetic screw insertion and removal cycles on reverse torque, (2) to determine whether a new screw, after multiple screw insertion cycles, affects reverse torque, and (3) to assess implant and prosthetic screw thread surface morphology with scanning electron microscopy (SEM). MATERIAL AND METHODS: One primary screw was paired with an implant (MT Osseospeed) and inserted to 25 Ncm torque 9, 19, 29, or 39 times (n=10). Primary screw reverse torque values were recorded after each insertion. A second, reference screw was then paired with each implant for a final screw insertion, and reverse torque was measured. Maximum, minimum, median, and mean values (P(max), P(min), P(median), and P(mean)) were identified for primary screws. A 1-way ANOVA and Tukey HSD post hoc analysis assessed the influence of multiple screw insertion cycles on P(max), P(min), P(median), and P(mean) values (α=.05). Confidence intervals were used to test differences between reference (REF) screw data and corresponding DMAX and DMIN (DMAX=P(max)-REF; DMIN=P(min)-REF). The surface topography of an unused implant and screw and of 1 implant and screw from each group was evaluated with SEM. RESULTS: Pairwise comparisons showed that 9 or fewer insertion cycles resulted in significantly greater mean reverse torque (20.9 ± 0.5 Ncm; P<.01). After 19, 29, or 39 cycles, the second, reference screw achieved significantly greater reverse torque than the minimum recorded values (P<.05). Implant thread surface morphology changes occurred primarily during the first 10 insertions. CONCLUSIONS: After 10 screw insertion cycles, a new prosthetic screw should be used with the implant system tested to maximize screw reverse torque and maintain preload when an abutment is definitively placed.

Objective measurement of periocular pigmentation.

PURPOSE: To evaluate the Minolta CR-400 chromameter in objectively measuring periocular/facial pigmentation in subjects of different ethnicities. METHODS: The CR-400 was used to obtain skin color measurements from 75 African-American, Caucasian and Hispanic subjects in 16 facial and periocular locations. Comparisons between ethnic and Fitzpatrick groups and instrument reliability were analyzed. RESULTS: Significant differences in L* were observed among all three ethnic groups, while values a* and b* were less sensitive to differences in pigmentation. Comparison between Fitzpatrick groups again identified value L* as being the most sensitive, demonstrating significant differences between the more heavily pigmented groups. The 16 facial locations measured were found to be statistically similar to each other, and the chromameter demonstrated excellent inter- and intra-instrument reliability. CONCLUSIONS: The Minolta CR-400 chromameter reliably measures facial pigmentation and can be useful for studies evaluating changes in skin pigmentation. Value L* is the parameter that is most sensitive to differences between ethnic and Fitzpatrick groups. Overlap between groups was observed, demonstrating that in future studies, each individual must serve as their own control when monitoring changes in pigmentation. The similarity between all the locations tested demonstrates uniformity of facial pigmentation within an individual.

Association of beta-blocker dose with serum procollagen concentrations and cardiac response to spironolactone in patients with heart failure.

STUDY OBJECTIVE: To determine whether beta-blocker dose influences cardiac collagen turnover and the effects of spironolactone on cardiac collagen turnover in patients with heart failure. DESIGN: Prospective clinical study. SETTING: Two heart failure centers. PATIENTS: Eighty-eight spironolactone-naïve patients with heart failure who were taking beta-blockers. INTERVENTION: In a subset of 29 patients, spironolactone was started at 12.5 mg/day, with the dosage titrated to 25 mg/day if tolerated. MEASUREMENTS AND MAIN RESULTS: Venous blood samples were collected from each patient. Serum procollagen type I and type III aminoterminal peptides (PINP and PIIINP) were determined by radioimmunoassay and compared between the 25 patients receiving low doses (< 50% of recommended target dose) and the 63 patients receiving high doses (> or = 50% of recommended target dose) of beta-blockers. Patients receiving low-dose beta-blockers had higher mean +/- SD PIIINP concentrations (6.6 +/- 3.5 vs 4.9 +/- 2.6 microg/L, p=0.03) and tended to have higher PINP concentrations (74.0 +/- 44.1 vs 57.1 +/- 28.6 microg/L, p=0.10) compared with those receiving high doses. A repeat blood sample was collected from the 29 patients who received spironolactone after 6 months of therapy. Changes in procollagen peptides also were compared in this subset between low-dose (9 patients) and high-dose (20 patients) beta-blocker groups. Low beta-blocker doses were associated with greater reductions in concentrations of PINP (median [intraquartile range] -14.3 microg/L [-9.8 to -19.3 microg/L] vs -2.5 microg/L [5.9 to -9.8 microg/L], p=0.02) and PIIINP (-1.4 microg/L [-0.9 to -2.4 microg/L] vs 0.1 microg/L [0.9 to -1.3 microg/L], p=0.045) with spironolactone therapy than high beta-blocker doses. In addition, 100% of the patients in this subset taking low-dose beta-blockers versus only 35% taking higher doses had reductions in both markers of cardiac fibrosis. CONCLUSION: Spironolactone may benefit patients with heart failure who cannot tolerate upward titration of beta-blocker dosages, at least in terms of its effects on cardiac remodeling.

Embolization of intracranial aneurysms with hydrogel-coated coils versus inert platinum coils: effects on packing density, coil length and quantity, procedure performance, cost, length of hospital stay, and durability of therapy.

BACKGROUND AND PURPOSE: The durability of aneurysm coil embolization is thought to depend on packing density. The expansile property of hydrogel coating on coils increases volumetric packing per coil length. We describe our experience using hydrogel-coated coils (HydroCoils) compared with inert platinum coils in intracranial aneurysm embolization. METHODS: Fifty aneurysms embolized primarily using HydroCoils from 2003 to 2004 were compared with 57 volume- and shape-matched aneurysms treated with standard platinum coils from 2000 to 2003. Outcome measures included volumetric percentage occlusion (VPO), length and number of coils used, procedure time, fluoroscopy time, contrast volume, coil cost, length of hospital stay, and durability of therapy. RESULTS: Seventeen/26/5 small/medium/large aneurysms treated with HydroCoils were matched with 29/24/4 small/medium/large aneurysms treated with inert platinum. HydroCoil embolization yielded significantly greater VPO (84.8% versus 29.8%; P<0.001), decreased average total coil length used per aneurysm (33.2 versus 44.3 cm), reduced fluoroscopy time (53.2 versus 65.2 minutes; P=0.016), but increased contrast volume used (174.8 versus 112.9 cc; P<0.001). There were no differences in length of hospital stay. Procedure-related morbidity and mortality rates in the HydroCoil cohort were 4% and 0%, respectively. Follow-up angiography at mean 12.3 months revealed lower aneurysm recurrence rates (17% versus 24%; number-needed-to-treat [NNT] 14.3). Initial costs associated with HydroCoil embolization were higher ($5835 versus $4017; P=0.004) but countered by lower retreatment rates (10% versus 17%; NNT 14.3). CONCLUSIONS: HydroCoil embolization achieves greater aneurysm packing density with decreased coil length. Initial durability data favor HydroCoils, with lower recurrence and retreatment rates.

Racial differences in patients' potassium concentrations during spironolactone therapy for heart failure.

STUDY OBJECTIVE: To determine whether the effects of spironolactone on potassium homeostasis vary by race by comparing serum potassium concentrations and potassium supplement use in African-American and Caucasian patients receiving spironolactone for heart failure. DESIGN: Retrospective medical record review. SETTING: Two heart failure centers. PATIENTS: Fifty African-American and 67 Caucasian patients with heart failure who were receiving a stable dosage of spironolactone in addition to standard heart failure therapy with an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker. MEASUREMENTS AND MAIN RESULTS: Medical records of eligible patients were reviewed by pharmacists and physicians who specialize in heart failure management. No significant differences were observed in diuretic therapy or renal function between racial groups; however, African-Americans were receiving higher doses of ACE inhibitors. African-Americans had lower serum potassium concentrations (4.2 +/- 0.4 vs 4.5 +/- 0.5 mEq/L, p<0.01) and a higher prevalence of potassium supplementation (48% vs 15%, p<0.01). In a subset of patients, spironolactone therapy was associated with a 2-fold greater increase in serum potassium concentration and a 3-fold greater reduction in potassium supplement use among Caucasians than African-Americans. CONCLUSION: Our findings suggest that a large percentage of patients with heart failure, particularly African-Americans, still require potassium supplementation despite treatment with spironolactone and standard vasodilator therapy.

Association of apolipoprotein E genotype with duration of time to achieve a stable warfarin dose in African-American patients.

STUDY OBJECTIVE: To test the hypothesis that genotypes for proteins affecting vitamin K availability influence the duration of time required to achieve a stable warfarin dose in African-American patients. DESIGN: Retrospective cohort study. SETTING: Pharmacist-managed antithrombosis clinic. PATIENTS: Ninety-two African-American adults whose warfarin therapy was initiated between September 2, 1999, and July 8, 2009. MEASUREMENTS AND MAIN RESULTS: During a routine anticoagulation clinic visit, a sample was collected from each patient for genetic analysis. genotyping was performed for the following variants: apolipoprotein E ε2, ε3, and ε4; NAD(P)H:quinone oxidoreductase (NQO1)*2; cytochrome P450 (CYP) 4F2 V433M; CYP2C9*2, *3, *5, *8, and *11; and vitamin K epoxide reductase complex 1 (VKORC1) -1639G>A. Patients' medical records were then reviewed, and data were collected retrospectively for each anticoagulation clinic visit during the first 6 months of warfarin therapy or until dose stabilization. The median time required to reach a stable warfarin dose, defined as the dose that produced therapeutic anticoagulation for three consecutive clinic visits, was 83 days. Compared with the 46 patients who achieved a stable warfarin dose within 83 days, the 46 patients who required longer durations for dose stabilization had a higher frequency of the apolipoprotein E ε3/ε3 genotype (37% vs 59%, p=0.037). Sixty-one percent of patients with the ε3/ε3 genotype versus 40% of those with an ε2 or ε4 allele had a delay in achieving a stable dose (p=0.037). Neither the CYP4F2 nor NQO1 genotype was associated with warfarin dose stabilization. CONCLUSION: Our data support the hypothesis that the apolipoprotein E genotype is associated with duration of time to reach a stable warfarin dose in African-American patients. Further insight into the genetic effects on warfarin dose stabilization could reveal novel methods to improve anticoagulation control during the warfarin initiation period.

Association of aldosterone concentration and mineralocorticoid receptor genotype with potassium response to spironolactone in patients with heart failure.

STUDY OBJECTIVE: To identify patient-specific factors associated with spironolactone-induced potassium level elevation in patients with heart failure. DESIGN: Prospective cohort study. SETTING: Two adult heart failure clinics. PATIENTS: Sixty-two adult (mean +/- SD age 54 +/- 16 yrs) aldosterone antagonist-naïve patients with heart failure. INTERVENTION: Patients received spironolactone 12.5 mg/day, titrated to 25 mg/day if tolerated. MEASUREMENTS AND MAIN RESULTS: Blood samples were obtained at baseline, 1 week after spironolactone initiation, and 1 week after spironolactone dose titration for assessment of baseline aldosterone level, serum chemistry, and angiotensinogen (AGT) c.-6G>A and p.M268T and mineralocorticoid receptor (NR3C2) c.215C>G and p.I180V genotypes. Patient characteristics, laboratory values, and genotypes were compared between those whose potassium levels increased by more than 0.5 mEq/L (15 patients) and those with lower potassium level elevations (47 patients) after spironolactone initiation and dose titration. Patients with a greater potassium level elevation had a higher mean +/- SD aldosterone concentration (178 +/- 92 vs 102 +/- 57 pg/ml, p=0.007) and NR3C2 215G allele frequency (50% vs 22%, p<0.01). Aldosterone concentrations positively correlated with diuretic dose (r=0.313, p=0.014) and negatively correlated with serum potassium level (r= -0.319, p=0.012). On regression analysis, factors predictive of potassium level increases greater than 0.5 mEq/L with spironolactone were aldosterone level greater than 150 pg/ml (odds ratio [OR] 30, 95% confidence interval [CI] 3.2-287] and NR3C2 215G carrier status (OR 17, 95% CI 1.6-167). CONCLUSION: Our data suggest that potassium should be monitored with particular caution when spironolactone is started in patients with heart failure who have evidence of elevated aldosterone levels, such as high diuretic requirements, or the NR3C2 215G allele.

Sex difference in the antiplatelet effect of aspirin in patients with stroke.

BACKGROUND: There is substantial interpatient variability in response to aspirin after an ischemic stroke or transient ischemic attack (TIA), as assessed by ex vivo effects of aspirin on platelet aggregation. The factors contributing to this variability are not well defined. OBJECTIVE: To determine whether demographic, social, or clinical characteristics are associated with ex vivo response to aspirin in patients with a history of stroke or TIA. METHODS: Eighty-one patients who were taking aspirin for secondary stroke prevention and underwent ex vivo platelet aggregation studies were identified. The medical records of eligible patients were reviewed by clinicians who specialize in the management of stroke patients. Characteristics were compared between 45 patients who had a complete response to aspirin and 36 patients who exhibited an incomplete (partial) response to aspirin based on the results of platelet aggregation testing. RESULTS: The median (range) aspirin dose was similar in complete (325; 81-1950 mg/day) and partial (325; 81-1300 mg/day) responders. There was no association between aspirin response and age, race, body mass index, medical history, smoking status, or use of statin or hormone replacement therapy. However, sex was significantly associated with response to aspirin, with more women in the partial versus complete responder group (75% vs 49%; p = 0.02). CONCLUSIONS: Our data suggest that aspirin may be less effective at inhibiting platelet aggregation in women compared with men who have a history of ischemic stroke or TIA.

O ecocardiograma na avaliaçäo de pacientes com hipertensäo arterial: aspectos anatômicos, funcionais e clínicos / The echocardiography in the evaluation of patients with arterial hypertension: anatomical, functional and clinical aspects

Foram estudadas 42 pacientes com hipertensäo arterial e 32 casos normais utilizando a ecocardiografia pelo modo M. Uma análise preliminar multivariada de 12 medidas ecocardiográficas mostrou que duas variáveis anatômicas (espessura diastólica de parede posterior e área interna da secçäo transversa do ventrículo esquerdo) e duas variáveis funcionais (velocidade médida de encurtamento circunferencial da fibra e velocidade de relaxamento da parede posterior do ventrículo esquerdo) podem discriminar os dois grupos pelo menos täo bem quanto o vetor original de doze variáveis. Estimou-se entäo uma regra diagnóstica indireta de acometimento cardíaco a partir destas quatro variáveis. O porcentual de erro limitou-se a 9,4% dos controles classificados como tendo cardiopatia hipertensiva e 7,1% dos hipertensos classificados como sem doença cardíaca. A análise simultânea das quatro medidas ecocardiográficas discriminantes levou à identificaçäo de cinco subtipos de acometimento cardíaco em pacientes com hipertensäo, definidos de acordo com as características ecocardiográficas anatômicas. Cada subtipo anatômicos mostra uma característica ecocardiográfica funcional diferente. Essa abordagem multivariada alerta o clínico que pacientes com hipertensäo têm combinaçöes diferentes de alteraçöes anatômicas e funcionais cardíacas e que o seu prognóstico pode depender da maneira como estas alteraçöes estäo combinadas