Placebo-controlled clinical trial evaluating 9.5% hydrogen peroxide high-adhesion whitening strips

OBJECTIVE

To evaluate the effectiveness and tolerability of an experimental 9.5% hydrogen peroxide whitening strip relative to a placebo control over a three-week period.

METHODS

In this parallel-design, double-blind clinical trial, 54 adult volunteers were randomized to an experimental 9.5% hydrogen peroxide whitening strip or placebo strip balancing for age and baseline tooth color, and received treatment. Strips were worn on the maxillary arch 30 minutes daily for 20 days. Efficacy was measured objectively as L*a*b* color change from digital images at Days 4, 7, 15, and 21.

RESULTS

As early as Day 4 and at all subsequent visits, the 9.5% strip group experienced significant (p < 0.004) color improvement relative to placebo for b* and L* color parameters. The amount of color improvement increased with continuing peroxide strip use. Mean ± SE between-group differences in Ab* were -0.6 ± 0.16, -0.8 ± 0.15, -1.6 ± 0.19, and -1.9 ± 0.20 at Days 4, 7, 15, and 21, respectively. Similar results were noted for AL*. Minor tooth sensitivity was the most common adverse event, as reported by 12% of subjects in the 9.5% strip group and 11% of subjects in the placebo group. No subjects discontinued treatment due to an adverse event.

CONCLUSION

This placebo-controlled clinical trial demonstrated that an experimental 9.5% hydrogen peroxide strip yielded significant tooth whitening relative to a placebo strip as early as after three days of product use.

Prognostic importance of serum alkaline phosphatase in CKD stages 3-4 in a clinical population

BACKGROUND

Elevated total serum alkaline phosphatase (ALP) levels have been associated with mortality in the general population and in dialysis patients.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

28,678 patients with chronic kidney disease (CKD) stages 3 and 4 (estimated glomerular filtration rate, 15-59 mL/min/1.73 m(2)) were identified using the Cleveland Clinic CKD Registry. CKD was defined as 2 estimated glomerular filtration rate values <60 mL/min/1.73 m(2) drawn more than 90 days apart using the CKD-EPI (CKD Epidemiology Collaboration) creatinine equation.

PREDICTOR

ALP levels measured using the calorimetric assay were examined as quartiles (quartile [Q]1, <66 U/L; Q2, 66-81 U/L; Q3, 82-101 U/L; and Q4, ≥102 U/L) and as a continuous measure.

OUTCOMES & MEASUREMENTS

All-cause mortality and end-stage renal disease (ESRD) were ascertained using the Social Security Death Index and US Renal Data System.

RESULTS

After a median follow-up of 2.2 years, 588 patients progressed to ESRD and 4,755 died. There was a graded increase in risk of mortality with higher ALP quartiles (Q2, Q3, and Q4) compared to the reference quartile (Q1) after adjusting for demographics, comorbid conditions, use of relevant medications, and liver function test results. The highest ALP quartile was associated with an HR for ESRD of 1.38 (95% CI, 1.09-1.76). Each 1-SD (42.7 U/L) higher ALP level was associated with 15% (95% CI, 1.09-1.22) and 16% (95% CI, 1.14-1.18) increased risk of ESRD and mortality, respectively.

LIMITATIONS

Single-center observational study; lack of complete data, including parathyroid hormone level, for all study participants, and attrition bias.

CONCLUSIONS

Higher serum ALP levels in patients with CKD stages 3-4 were associated independently with all-cause mortality and ESRD.

Cementation of indirect restorations: an overview of resin cements

The process of ensuring proper retention, marginal seal, and durability of indirect restorations depends heavily on effective cementation. Careful consideration must be made when selecting an adhesive cement for a given application. This article provides information on resin cements that can guide clinicians in determining which type of cement is best suited to their clinical needs regarding cementation of indirect restorations. Emphasis is placed on successful cementation of all-ceramic restorations.

Considerations for proper selection of dental cements

Selecting the proper cement for sufficient bond strength has become progressively complicated as the number of different materials for indirect restorations has increased. The success of any restoration is highly dependent on the proper cement being chosen and used. The function of the cement is not only to seal the restoration on the tooth but also, in some cases, to support the retention of the restoration. This ability to strengthen retention varies by the cement chosen by the clinician; therefore, careful consideration must precede cement selection.

Integrating the CEREC technology at UT College of Dentistry

The computer-aided design/computer-aided manufacturing (CAD/CAM) has evolved during the past 25 years, and this evolution has improved the speed and precision in which dentists can deliver high quality esthetic restorations. CEREC is an acronym for "ceramic reconstruction" and is one of the CAD/CAM systems available to dentists in private practice. The University of Tennessee College of Dentistry was one of the first dental schools in the United States to embrace this technology and integrate it into the four-year curriculum. In a dental school setting, this technology can prove to be an educational tool for the dental students, cost effective for the University and provide exceptional service for the patients.

Serum bicarbonate and mortality in stage 3 and stage 4 chronic kidney disease

BACKGROUND AND OBJECTIVES

The incidence and prevalence of metabolic acidosis increase with declining kidney function. We studied the associations of both low and high serum bicarbonate levels with all-cause mortality among stage 3 and 4 chronic kidney disease (CKD) patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We examined factors associated with low (<23 mmol/L) and high (>32 mmol/L) serum bicarbonate levels using logistic regression models and associations between bicarbonate and all-cause mortality using Cox-proportional hazard models, Kaplan-Meier survival curves, and time-dependent analysis.

RESULTS

Out of 41,749 patients, 13.9% (n = 5796) had low and 1.6% (n = 652) had high serum bicarbonate levels. After adjusting for relevant covariates, there was a significant association between low serum bicarbonate and all-cause mortality (hazard ratio [HR] 1.23, 95% CI 1.16, 1.31). This association was not statistically significant among patients with stage 4 CKD and diabetes. The time-dependent analysis demonstrated a significant mortality risk associated with a decline from normal to low bicarbonate level (HR 1.59, 95% CI 1.49, 1.69). High serum bicarbonate levels were associated with death irrespective of the level of kidney function (HR 1.74, 95% CI 1.52, 2.00). When serum bicarbonate was examined as a continuous variable, a J-shaped relationship was noted between serum bicarbonate and mortality.

CONCLUSIONS

Low serum bicarbonate levels are associated with increased mortality among stage 3 CKD patients and patients without diabetes. High serum bicarbonate levels are associated with mortality in both stage 3 and stage 4 CKD patients.

Low 25-hydroxyvitamin D levels and mortality in non-dialysis-dependent CKD

BACKGROUND

Low 25-hydroxyvitamin D (25[OH]D) levels are common in patients with non-dialysis-dependent chronic kidney disease (CKD). The associations between low 25(OH)D levels and mortality in non-dialysis-dependent patients with CKD are unclear.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Patients with stages 3-4 CKD (estimated glomerular filtration rate, 15-59 mL/min/1.73 m(2); n = 12,673) who had 25(OH)D levels measured after the diagnosis of CKD in the Cleveland Clinic Health System.

PREDICTOR

25(OH)D levels categorized into 3 groups: <15, 15-29, and ≥30 ng/mL.

OUTCOMES

We examined factors associated with low 25(OH)D levels and associations between low 25(OH)D levels and all-cause mortality (ascertained using the Social Security Death Index and our electronic medical record) using logistic regression, Cox proportional hazard models, and Kaplan-Meier survival curves.

MEASUREMENTS

25(OH)D was measured using chemiluminescence immunoassay.

RESULTS

Of 12,763 patients with CKD, 15% (n = 1,970) had 25(OH)D levels <15 ng/mL, whereas 45% (n = 5,749) had 25(OH)D levels of 15-29 ng/mL. Male sex, African American race, diabetes, coronary artery disease, and lower estimated glomerular filtration rate were associated significantly with 25(OH)D level <30 ng/mL. A graded increase in risk of 25(OH)D level <30 ng/mL was evident across increasing body mass index levels. Patients who had 25(OH)D levels measured in fall through spring had higher odds for 25(OH)D levels <30 ng/mL. After covariate adjustment, patients with CKD with 25(OH)D levels <15 ng/mL had a 33% increased risk of mortality (95% CI, 1.07-1.65). The group with 25(OH)D levels of 15-29 ng/mL did not show a significantly increased risk of mortality (HR, 1.03; 95% CI, 0.86-1.22) compared with patients with 25(OH)D levels ≥30 ng/mL.

LIMITATIONS

Single-center observational study, lack of data for albuminuria and other markers of bone and mineral disorders, and attrition bias.

CONCLUSIONS

25(OH)D level <15 ng/mL was associated independently with all-cause mortality in non-dialysis-dependent patients with CKD.

IgA-dominant Staphylococcus infection-associated glomerulonephritis: case reports and review of the literature

Background and objectives. The mesangial deposition of IgA is rarely described with proliferative glomerulonephritis associated with Staphylococcus infection. Recently, this association has been increasingly recognized possibly due to the increased rate of Staphylococcus infection.

Design setting, participants and measurements. We report two cases of methicillin-sensitive Staphylococcus aureus bacteremia associated with acute proliferative glomerulonephritis with dominant mesangial deposit of IgA. We searched MEDLINE (1960–2009) for similar reports. We pooled individual patient data and reported descriptive statistics of all published cases.

Results. Forty-six cases were included in the final analysis. The mean age of presentation was 59, with a male predominance (84%). Clinical presentation was notable for rapidly progressive glomerulonephritis with nephrotic-range proteinuria and normal complement levels in 52 and 72%, respectively. Methicillin-resistant S. aureus (68%) was the most common pathogen isolated with a latent period ranging from 1 to 16 weeks. Diffuse mesangial proliferation was commonly found with crescentic lesions noted in 35% of the cases. Antimicrobial treatment was associated with renal recovery in 58% of the cases. Need for renal replacement therapy was significantly associated with pre-existing diabetes, hypertension and interstitial fibrosis seen on kidney biopsy.

Conclusions. IgA-dominant post-Staphylococcus glomerulonephritis is a rare clinical entity with certain unique clinical and morphologic features. It is difficult to differentiate from primary IgA nephropathy in cases where the infection is not apparent. An acute onset of rapidly progressive glomerulonephritis, with normal complement levels and deposition of mesangial IgA in an elderly patient should raise suspicion for this rare form of glomerulonephritis.

Tensile bond strength of ceramic crowns to dentin using resin cements

PURPOSE

This study measured the bond strength of the self-adhesive resin cements and a bonded resin cement for crowns bonded to extracted teeth with preparations having a total taper greater than 30 degrees. A crown pull-off test was used with direction of pull along the path of insertion. The CAD/CAM system Cerec was used to create crowns with the pull-off loop as an integral part of the crown structure.

MATERIALS AND METHODS

One hundred extracted human molars were prepared for all-ceramic crowns with a 1.5-mm shoulder, greater than 30-degree axial wall convergence, a flat occlusal surface and 3 to 5 mm occlusal/ gingival height. All-ceramic crowns were cemented with five different self-adhesive cements (Rely X Unicem, Maxcem Elite, BisCem, SmartCem 2, and G-Cem) and one bonded resin cement (Multilink). Forfour cements (excluding GCem and Multilink) there were 2 groups, one with HF etching and one without ceramic surface treatment. The crowns were then subject to tensile stress until either the crown fractured or the crown was lifted off from the tooth.

RESULTS

For several cements, the bond strength exceeded the tensile strength of the all-ceramic crown; thus, the crown fractured, leaving the cemented part of the crown on the tooth. The effect of ceramic surface etching was not statistically significant at p = 0.05; however, for each cement, the treated crowns showed a lower coefficient of variance (COV). For this study, the COV ranged from 24.9 % to 97.9 %. Loads ranged from 41.3 to 190.3 N.

CONCLUSION

Some of the new self-etching resin cements can create bonds to non-retentive crown preparations that are stronger than the strength of a ceramic crown; however, these high bond strengths may not be able to be achieved consistently.

Implications of the CKD-EPI GFR estimation equation in clinical practice

BACKGROUND AND OBJECTIVES

Chronic kidney disease (CKD) is a significant public health problem whose diagnosis and staging relies upon GFR-estimating equations, including the new CKD-EPI equation. CKD-EPI demonstrated superior performance compared with the existing MDRD equation but has not been applied to a healthcare system.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We identified 53,759 patients with stages 3 to 5 CKD on the basis of either MDRD or CKD-EPI equations using two eGFR values <60 ml/min per 1.73 m² > 90 days apart from an outpatient setting. We compared patient characteristics, presence of related diagnosis codes, and time CKD classification between equations.

RESULTS

The number of patients identified with CKD decreased 10% applying CKD-EPI versus MDRD. Changes varied substantially by patient characteristics including a 35% decrease among patients < 60 years and a 10% increase among patients > 90 years. Women, non-African Americans, nondiabetics, and obese patients were less likely to be classified on the basis of CKD-EPI. Time to CKD classification was significantly longer with CKD-EPI among younger patients. 14% of patients identified with CKD on the basis of either estimating equation also had a related ICD-9 diagnosis, ranging from 19% among patients < 60 years to 7% among patients > 90 years.

CONCLUSIONS

Consistent with findings in the general population, CKD-EPI resulted in substantial declines in equation-based CKD diagnoses in a large healthcare system. Further research is needed to determine whether widespread use of CKD-EPI with current guidelines could lead to delayed needed care among younger patients or excessive referrals among older patients.

Development and validation of an electronic health record-based chronic kidney disease registry

BACKGROUND AND OBJECTIVES

Chronic kidney disease (CKD) is increasing, and outcomes-related research from diverse health care settings is needed to target appropriate efforts and interventions. We developed an electronic health record (EHR)-based CKD registry at the Cleveland Clinic and validated comorbid conditions.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Patients who had at least one face-to-face outpatient encounter with a Cleveland Clinic health care provider and (1) had two estimated GFR values <60 ml/min per 1.73 m(2) >90 days apart as of January 1, 2005 and/or (2) were patients with International Classification of Diseases-9 (ICD-9) diagnosis codes for kidney disease were included.

RESULTS

Our registry includes 57,276 patients (53,399 patients met estimated GFR criteria and 3877 patients met ICD-9 diagnosis code criteria) as of March 2010. Mean age was 69.5 ± 13.4 years, with 55% women and 12% African Americans. Medicare is the primary insurer for more than one half of the study cohort. The κ statistics to assess the extent of agreement between the administrative dataset extracted from the EHR and actual EHR chart review showed substantial agreement (>0.80) for all conditions except for coronary artery disease and hypertension, which had moderate agreement (<0.60).

CONCLUSIONS

Development of an EHR-based CKD registry is feasible in a large health system, and the comorbid conditions included in the registry are reliable. In addition to conducting research studies, such a registry could help to improve the quality of care delivered to CKD patients and complement the ongoing nationwide efforts to develop a CKD surveillance project.

HCV in patients with end-stage renal disease

Chronic hepatitis C virus (HCV) infection remains an important cause of liver disease in patients with end-stage renal disease (ESRD) and conversely, renal failure has a significant impact on morbidity and mortality throughout the natural history of chronic HCV and its treatment. With improved awareness within dialysis units of the potential for spread and the institution of preventative measures, the prevalence of HCV infection in the hemodialysis-dependent population has continued to decline since 1995. Use of HCV (+) donor kidneys is associated with an increase in the prevalence of liver disease, but when compared with continued hemodialysis, transplantation using these kidneys is associated with improved survival. Overall, survival in patients with chronic HCV infection appears to be better after renal transplantation when compared with maintenance hemodialysis, and transplant should be considered for these patients. Data support the use of interferon and the improved efficacy of pegylated interferon formulations for treatment of chronic HCV infection in ESRD patients, although tolerability continues to be troublesome. The newest and most promising data regarding the treatment of HCV in ESRD involve the combination of reduced dose ribavirin with interferon or pegylated interferon suggesting similar enhancements in sustained virologic response (SVR) as seen in non-ESRD patients, but caution is advised, as all studies to date used ribavirin plasma concentration monitoring in patient with ESRD. Finally, with regard to postrenal transplant treatment of HCV infection, there is no evidence to support treatment with interferon-based therapy and pretransplant treatment remains the best option whenever possible.

Computer-assisted learning and simulation lab with 40 DentSim units

There are an increasing number of studies about the computer-assisted dental patient simulator DentSim (DenX, Israel), by which dental students can acquire cognitive motor skills in a multimedia environment. However, only a very few studies have been published dealing with efficient ways to use and to manage a computer-assisted dental simulation lab with 40 DentSim units. The current approach and optimization steps of the College of Dentistry at the University of Tennessee Health Science Center were evaluated based on theoretical and practical tests and by questionnaires (partial 5-point Likert scale). Half of the D1 (first-year) students (2004/05) already had experience with computer-assisted learning at their undergraduate college and most of the students even expected to be taught via computer-assisted learning systems (83.5%) at the dental school. 87.3% of the students working with DentSim found the experience to be very interesting or interesting. Before the students carried out the preparation exercises, they were trained in the skills they needed to work with the sophisticated technology, eg, system-specific operation skills (66.6% attained maximal reachable points) and information searching skills (79.5% attained maximal reachable points). The indirect knowledge retention rate / incidental learning rate of the preparation exercises in the sense of computer-assisted problem-oriented learning regarding anatomy, preparation procedures, and cavity design was promising. The wide- ranging number of prepared teeth needed to acquire the necessary skills shows the varied individual learning curves of the students. The acceptance of, and response to, additional elective training time in the computer-assisted simulation lab were very high. Integrating the DentSim technology into the existing curriculum is a way to improve dental education, but it is also a challenge for both teachers and the students. It requires a shift in both curriculum and instructional goals that have to be reevaluated and optimized continuously.

Evaluation of two different teaching concepts in dentistry using computer technology

The common teaching goal of two different phantom head courses was to enable the students to provide an all-ceramic restoration by the means of computer technology. The aim of this study was to compare these two courses with regard to the different educational methods using identical computer software. Undergraduate dental students from a single year were randomly assigned to two different courses. One course was a conventional teacher-centred course [TRAD]. The other course contained problem-based learning (PBL) oriented structured modules [HYBRID]. The students completed an evaluation based on a 25 item seven-point Likert scale. Two independent evaluators assessed the practical work. Differences between TRAD and HYBRID were tested for significance using the Mann-Whitney U-test (at p < or = 0.05). Both courses were rated as demanding. The HYBRID group rated those items significantly better, which focused on course atmosphere and student-teacher relationship. The TRAD group felt that their course was more satisfying. Practical results of the two groups did not differ significantly. Within the limits of the study it was revealed, that the HYBRID group was less satisfied with the own success although the learning conditions were rated better. This could be interpreted in two ways: (1) the PBL oriented course lead the students to more self skepticism to their own work or (2) due to increased intellectual demands and the lack of detailed guidelines the course was felt as more burdening.

Dentist-time expenditure for two different adhesive all-ceramic systems

OBJECTIVES

The purpose of this clinical investigation was to compare a chair-side adhesive all-ceramic system to a laboratory processed adhesive all-ceramic system with respect to quality and time expenditure for the dentist.

METHODS

The same dentist treated 10 patients, who were each to receive two large posterior single tooth restorations of similar location and extent. One restoration was made in the laboratory by using the IPS Empress system [LAB], the other one was done chair-side by utilizing the Cerec system [CHAIR]. The time expenditure was measured for [LAB] and [CHAIR] and compared by the Wilcoxon signed rank test. The restorations were also evaluated according to the USPHS criteria.

RESULTS

The mean time expenditure for the dentist with low-level assistance was 111:03 min [S.D.+/-24:09 min] for [LAB] and 115:31 min [S.D.+/-15:54 min] for [CHAIR]. Time expenditure with medium level assistance for the operator was 100:53 min [S.D.+/-23:59] for [LAB] and 105:50 [S.D.+/-15:28] for [CHAIR]. Assuming a high level of assistance, the mean time values were 53:11 min [S.D.+/-14:29] for [LAB] and 54:29 min [S.D.+/-09:21] for [CHAIR]. The baseline investigation according to the modified USPHS criteria did not reveal any differences between [CHAIR] and [LAB].

CONCLUSION

There were no statistical significant differences with respect to time expenditure or quality between [LAB] and [CHAIR] in this study.

Induction sirolimus and delayed graft function after deceased donor kidney transplantation in the United States

BACKGROUND/AIMS

Previous studies have reported a link between the use of induction sirolimus (INDSRL) and delayed graft function (DGF) after kidney transplantation. However, none have had sufficient power to adjust for all factors known to be associated with DGF.

METHODS

We conducted a retrospective cohort study of US deceased donor kidney transplantation recipients in the United States Renal Data System (USRDS) from January 1, 2000 to May 31, 2001. Logistic regression analysis was used to model adjusted odds ratios (AOR) for the development of DGF, adjusted for other factors previously reported to be associated with DGF.

RESULTS

Among 8,319 patients meeting inclusion criteria, 361 patients received INDSRL, of whom 98 (27.1%) had DGF, compared to 22.5% among patients who did not receive INDSRL. In multivariate analysis, INDSRL was associated with an increased risk of DGF, with an adjusted odds ratio of 1.42 (95% CI: 1.07-1.90). Other factors associated with DGF were similar to those previously reported. INDSRL was not significantly associated with graft loss at 1 year in Cox regression.

CONCLUSIONS

INDSRL was independently associated with DGF in US deceased donor kidney transplantation recipients, adjusted for all other factors previously shown to be associated with DGF.

Effect of four intermediate layer treatments on microleakage of Class II composite restorations

This in vitro study examines the marginal sealing ability of four different intermediate materials applied before placement of a condensable composite. Class II preparations were made with gingival margins placed 1.0 mm apical to the cementoenamel junction of 60 extracted teeth, randomly assigned to five groups of 12. Following restoration, teeth were thermocycled, soaked in 0.5% basic fuchsin, and sectioned longitudinally. The resin-modified glass ionomer cement demonstrated significantly less microleakage than the use of a dentin bonding agent alone or in combination with flowable composite, flowable compomer, or autoploymerizing composite (p < 0.05, Dunn's test). This study supports the use of the glass ionomer open sandwich technique in deep Class II direct composite restorations.

Retain or extract: the decision process

It is difficult to give up attempts to save a tooth and decide to extract. Sometimes the decision is easy because experience allows the dentist to evaluate the patient and the situation and make an educated prognosis for the tooth. The thought process is extremely involved and many variables must be taken into consideration, some of which the dentist has very little control over. The process was much less involved when there were fewer options available to the patient and the dentist. Teeth in themselves are very rarely hopeless; it is the desires of the patient, the expertise of the dentist, and the conditions of the oral environment that lead to a hopeless prognosis. A tooth can be moved to another place in the mouth or even into another patient's mouth, and the treatment decision changes, making it not as hopeless. The wish of the patient is usually the final, determining factor for how treatment is carried out. Patients make the decision whether to spend their time and money to save the tooth with extraordinary effort or whether to cut their losses and give up on the tooth.

A clinical comparison of two bleaching systems

Recent improvements in the in-office techniques for bleaching teeth have reduced chair time, simplified the procedure and reduced the potential for pulpal inflammation and other side effects. Home bleaching has become very popular, but many patients will still prefer the faster, in-office procedure done by their dentist. This comparison of two 35 percent hydrogen peroxide products confirms that these procedures are effective and should be a part of any practice providing esthetic improvements for its patients.

The injection procedure as a source of stress for dentists

A questionnaire was mailed to 3,000 practicing dentists to inquire about their physical and psychological responses to injecting local anesthesia; 711 dentists completed questionnaires (a 24 percent response rate). Six percent of respondents considered their thoughts and feelings associated with injection to be a serious problem; two percent reported no negative reactions to this aspect of clinical practice. Reported reactions to various anesthetic procedures were compared, and the various responses are discussed. Injection of local anesthesia, rarely discussed in the literature, contributes significantly to overall stress of dentists, but not all dentists.