Facility characteristics preferred by older men seeking medical male circumcision services in Kenya: qualitative findings from the 'Tasco' study (May 2014-June 2016).

Primary healthcare facilities are central to the implementation of voluntary medical male circumcision (VMMC) as points of access to integrated health services in line with the Kenya AIDS Strategic Framework II (2020/21-2024/25). Knowledge of factors that explain men's uptake of VMMC and sexual health services at these facilities and preferences of where to get the services remain poorly understood. Using qualitative methodologies, we examined factors that determined facility choice for VMMC services and reasons for preferring the facility among men aged 25-39 years who previously underwent VMMC. The current study draws from focus group discussion interviews with circumcised men and their partners conducted as part of a randomized controlled trial to assess impact of two demand creation interventions in western Kenya. This involved 12 focus group discussions (FGD) with 6-10 participants each. Six FGDs were conducted with circumcised men, and 6 with their sex partners. Thematic issues relevant to a predetermined framework were identified. The themes were organized as follows: service availability, accessibility, affordability, appropriateness and, acceptability. Facility location, physical layout, organization of patient flow, infrastructure, and service provider skills were the outstanding factors affecting the choice of VMMC service outlets by men aged 25-39 years. Additionally, preferences were influenced by individual's disposition, attitudes, knowledge of VMMC services and tacit balance between their own recognized health needs versus desire to conform to social-cultural norms. Facility choice and individual preference are intricate issues, simultaneously involving multiple but largely intra-personal and facility-level factors. The intrapersonal dimensions elicited may also reflect differential responses to strategic communications and demand creation messages with promotion and prevention frames.

Ethical issues evolving from patients' perspectives on compulsory screening for syphilis and voluntary screening for cervical cancer in Kenya.

BACKGROUND: Public health aims to provide universal safety and progressive opportunities to populations to realise their highest level of health through prevention of disease, its progression or transmission. Screening asymptomatic individuals to detect early unapparent conditions is an important public health intervention strategy. It may be designed to be compulsory or voluntary depending on the epidemiological characteristics of the disease. Integrated screening, including for both syphilis and cancer of the cervix, is a core component of the national reproductive health program in Kenya. Screening for syphilis is compulsory while it is voluntary for cervical cancer. Participants' perspectives of either form of screening approach provide the necessary contextual information that clarifies mundane community concerns. METHODS: Focus group discussions with female clients screened for syphilis and cancer of the cervix were conducted to elicit their perspectives of compulsory and voluntary screening. The discussions were audiotaped, transcribed and thematic content analysis performed manually to explore emerging ethics issues. RESULTS: The results indicate that real ethical challenges exist in either of the approaches. Also, participants were more concerned about the benefits of the procedure and whether their dignity is respected than the compulsoriness of screening per se. The implication is for the policy makers to clarify in the guidelines how to manage ethical challenges, while at the operational level, providers need to be judicious to minimize potential harms participants and families when screening for disease in women. CONCLUSIONS: The context for mounting screening as a public health intervention and attendant ethical issues may be more complex than hitherto perceived. Interpreting emerging ethics issues in screening requires more nuanced considerations of individuals' contextual experiences since these may be contradictory to the policy position. In considering mounting screening for Syphilis and cervical cancer as a public heal intervention, the community interests and perspectives should be inculcated into the program. Population lack of information on procedures may influence adversely the demand for screening services by the individuals at risk or the community as a collective agent.

Predictors of mortality and survival probability distribution among patients on tuberculosis treatment in Vihiga County, Kenya.

Background: Tuberculosis (TB) related mortality remains a serious impediment in ending TB epidemic. Objective: To estimate survival probability and identify predictors, causes and conditions contributing to mortality among TB patients in Vihiga County. Methods: A cohort of 291 patients from 20 purposively selected health facilities were prospectively considered. Data was obtained by validated questionnaires through face-to-face interviews. Survival probabilities were estimated using Kaplan-Meier method while Cox proportional hazard model identified predictors of TB mortality through calculation of hazard ratios at 95% confidence intervals. Mortality audit data was qualitatively categorized to elicit causes and conditions contributing to mortality. Results: 209 (72%) were male, median age was 40 (IQR=32-53) years while TB/HIV coinfection rate was 35%. Overall, 45 (15%) patients died, majority (78% (log rank<0.001)) during intensive phase. The overall mortality rate was 32.2 (95% CI 23.5 - 43.1) deaths per 1000 person months and six months' survival probability was 0.838 (95% CI, 0.796-0.883). Mortality was higher (27%) among HIV positive than HIV negative (9%) TB patients. Independent predictors of mortality included; comorbidities (HR = 2.72, 95% CI,1.36-5.44, p< 0.005), severe illness (HR=5.06, 95% CI,1.59-16.1, p=0.006), HIV infection (HR=2.56, 95% CI,1.28-5.12, p=0.008) and smoking (HR=2.79, 95% CI,1.01-7.75, p=0.049). Independent predictors of mortality among HIV negative patients included; comorbidities (HR = 4.25, 95% CI; 1.15-15.7, p = 0.03) and being clinically diagnosed (HR = 4.8, 95% CI; 1.43-16, P = 0.01) while among HIV positive; they included smoking (HR = 4.05, 95% CI;1.03-16.0, P = 0.04), severe illness (HR = 5.84, 95% CI; 1.08-31.6, P = 0.04), severe malnutrition (HR = 4.56, 95% CI; 1.33-15.6, P = 0.01) and comorbidities (HR = 3.04, 95% CI; 1.03-8.97, p = 0.04). More than a half (52%) of mortality among HIV positive were ascribed to advanced HIV diseases while majority of (72%) of HIV negative patients died to TB related lung disease. Conditions contributing to mortality were largely patient and health system related. Conclusion: Risk of TB mortality is high and is attributable to comorbidities, severe illness, HIV and smoking. Causes and conditions contributing to TB mortality are multifaceted but modifiable. Improving TB/HIV care could reduce mortality in this setting.

Determinants of tuberculosis treatment interruption among patients in Vihiga County, Kenya.

BACKGROUND: Despite robust Tuberculosis (TB) program with effective chemotherapy and high coverage, treatment interruption remains a serious problem. Interrupting TB treatment means that patients remain infectious for longer time and are at risk of developing drug resistance and death. This study was conducted to identify and describe predictors of TB treatment interruption. METHODS: A cohort of 291 notified TB patients from 20 selected health facilities in Vihiga County were enrolled in to the study and followed up until the end of treatment. Patient characteristics that potentially predict treatment interruption were recorded during treatment initiation using structured questionnaires. Patients who interrupted treatment were traced and reasons for stoppage of treatment recorded. Kaplan Meier method was used to estimate probabilities of treatment interruption by patient characteristics and determine time intervals. The Log rank test for the equality of survival distributions analyzed significance of survival differences among categorical variables. For multivariable analysis, Cox proportional hazard model, was fitted to identify predictors of TB treatment interruption through calculation of hazard ratios with 95% Confidence Intervals (CIs). For variable analysis, statistical significance was set at P ≤ 0.05. Reasons for treatment interruption were categorized according to most recurrent behavioral or experiential characteristics. RESULTS: Participants' median age was 40 years (IQR = 32-53) and 72% were male. Of the 291 patients, 11% (n = 32) interrupted treatment. Incidences of treatment interruption significantly occurred during intensive phase of treatment. Independent predictors of treatment interruption included alcohol consumption (HR = 9.2, 95% CI; 2.6-32.5, p < 0.001), being female (HR = 5.01, 95% CI; 1.68-15.0, p = 0.004), having primary or lower education level (HR = 3.09, 95% CI; 1.13-8.49, p < 0.029) and having a treatment supporter (HR = 0.33, 95% CI; 0.14-0.76, p = 0.009). Reasons for interrupting treatment were categorized as: alcoholism, feeling better after treatment initiation, associated TB stigma, long distance to health facility, lack of food, perception of not having TB and pill burden. CONCLUSION: TB treatment interruption was high and largely associated with patients' socio-demographic and behavioral characteristics. These multidimensional factors suggest the need for interventions that not only target individual patients but also environment in which they live and receive healthcare services.

In vivo acid etching effect on bacteria within caries-affected dentin.

Acid etching procedures may disrupt residual bacteria and contribute to the success of incomplete caries removal followed by adhesive restoration. This study evaluated the in vivo effect of acid etching on cariogenic bacterial activity within affected dentin after minimally invasive treatment of caries lesions. Twenty-eight carious permanent teeth received standardized selective caries removal and random acid etch treatment (E) or not (NE) prior to adhesive restoration. Baseline and 3-month dentin biopsies were collected. The number of bacteria and activity of total bacterial cells and Streptococcus mutans were determined by quantitative PCR and RT-PCR. No statistically significant differences were observed in total bacterial number and activity between E and NE treatments (p > 0.3008). For NE, however, the residual S. mutans bacterial cells were reduced (p = 0.0027), while the activity per cell was significantly increased (p = 0.0010) after reentry at 3 months after restoration. This effect was not observed in group E. Although no significant differences were found between groups, this study suggests that acid etching of affected dentin prior to adhesive restoration may directly or indirectly have an inhibitive effect on the activity of residual cariogenic bacteria. Further research is required to investigate this potential effect.

Overcoming the barriers experienced in conducting a medication trial in adults with aggressive challenging behaviour and intellectual disabilities.

BACKGROUND: Aggressive challenging behaviour in people with intellectual disability (ID) is frequently treated with antipsychotic drugs, despite a limited evidence base. METHOD: A multi-centre randomised controlled trial was undertaken to investigate the efficacy, adverse effects and costs of two commonly prescribed antipsychotic drugs (risperidone and haloperidol) and placebo. RESULTS: The trial faced significant problems in recruitment. The intent was to recruit 120 patients over 2 years in three centres and to use a validated aggression scale (Modified Overt Aggression Scale) score as the primary outcome. Despite doubling the period of recruitment, only 86 patients were ultimately recruited. CONCLUSIONS: Variation in beliefs over the efficacy of drug treatment, difficulties within multidisciplinary teams and perceived ethical concerns over medication trials in this population all contributed to poor recruitment. Where appropriate to the research question cluster randomised trials represent an ethically and logistically feasible alternative to individually randomised trials.

Patient-level cost of home- and facility-based child pneumonia treatment in Suba Sub County, Kenya.

BACKGROUND: Globally, pneumonia accounted for 16% of deaths among children under 5 years of age and was one of the major causes of death overall in 2018. Kenya is ranked among the top 15 countries with regard to pneumonia prevalence and contributed approximately 74% of the world's annual pneumonia cases in 2018. Unfortunately, less than 50% of children with pneumonia receive appropriate antibiotics for treatment. Homa-Bay County implemented pneumonia community case management utilizing community health workers, as recommended by the World Health Organization (WHO), in 2014. However, since implementation of the program, the relative patient-level cost of home-based and facility-based treatment of pneumonia, as well as the main drivers of these costs in Suba Subcounty, remain uncertain. Therefore, the main objective of this study was to compare the patient-level costs of home based treatment of pneumonia by a community health worker with those of health facility-based treatment. METHODS AND FINDINGS: Using a cross-sectional study design, a structured questionnaire was used to collect quantitative data from 208 caregivers on the direct costs (consultation, medicine, transportation) and indirect costs (opportunity cost) of pneumonia treatment. The average household cost for the community managed patients was KSH 122.65 ($1.29) compared with KSh 447.46 ($4.71), a 4-fold difference, for those treated at the health facility. The largest cost drivers for home treatment and health facility treatment were opportunity costs (KSH 88.25 ($ 0.93)) and medicine costs (KSH 126.16 ($ 1.33)), respectively. CONCLUSION: This study demonstrates that the costs incurred for home-based pneumonia management are considerably lower compared to those incurred for facility-based management. Opportunity costs (caregiver time and forgone wages) and the cost of medication were the key cost-drivers in the management of pneumonia at the health facility and at home, respectively. These findings emphasize the need to strengthen and scale community case management to overcome barriers and delays in accessing the correct treatment for pneumonia for sick children under 5 years of age.

Voluntary medical male circumcision scale-up in Nyanza, Kenya: evaluating technical efficiency and productivity of service delivery.

BACKGROUND: Voluntary medical male circumcision (VMMC) service delivery is complex and resource-intensive. In Kenya's context there is still paucity of information on resource use vis-à-vis outputs as programs scale up. Knowledge of technical efficiency, productivity and potential sources of constraints is desirable to improve decision-making. OBJECTIVE: To evaluate technical efficiency and productivity of VMMC service delivery in Nyanza in 2011/2012 using data envelopment analysis. DESIGN: Comparative process evaluation of facilities providing VMMC in Nyanza in 2011/2012 using output orientated data envelopment analysis. RESULTS: Twenty one facilities were evaluated. Only 1 of 7 variables considered (total elapsed operation time) significantly improved from 32.8 minutes (SD 8.8) in 2011 to 30 minutes (SD 6.6) in 2012 (95%CI = 0.0350-5.2488; p = 0.047). Mean scale technical efficiency significantly improved from 91% (SD 19.8) in 2011 to 99% (SD 4.0) in 2012 particularly among outreach compared to fixed service delivery facilities (CI -31.47959-4.698508; p = 0.005). Increase in mean VRS technical efficiency from 84% (SD 25.3) in 2011 and 89% (SD 25.1) in 2012 was not statistically significant. Benchmark facilities were #119 and #125 in 2011 and #103 in 2012. Malmquist Productivity Index (MPI) at fixed facilities declined by 2.5% but gained by 4.9% at outreach ones by 2012. Total factor productivity improved by 83% (p = 0.032) in 2012, largely due to progress in technological efficiency by 79% (p = 0.008). CONCLUSIONS: Significant improvement in scale technical efficiency among outreach facilities in 2012 was attributable to accelerated activities. However, ongoing pure technical inefficiency requires concerted attention. Technological progress was the key driver of service productivity growth in Nyanza. Incorporating service-quality dimensions and using stepwise-multiple criteria in performance evaluation enhances comprehensiveness and validity. These findings highlight site-level resource use and sources of variations in VMMC service productivity, which are important for program planning.

Decision making in psychiatric civil commitment: an experimental analysis.

OBJECTIVE: Legislation in Canada and the United States that was intended to decrease the use of civil commitment has resulted in a paradoxical increase in involuntary hospital admissions. To elucidate the reasons for this increase, this study was designed to assess the relative importance of various factors involved in the decision to commit a patient. METHOD: All psychiatrists in Ontario were sent a questionnaire asking them to make commitment decisions based on hypothetical case vignettes. Four factors were systematically varied in the vignettes: the patients' legal commitability, clinical treatability, alternative resources, and psychotic symptoms. Completed questionnaires, with three vignettes each, were returned by 495 respondents. RESULTS: All four variables were statistically significant in the expected direction; legal commitability (i.e., dangerousness to self and/or others, inability to care for self) and presence of psychotic symptoms accounted for the majority of the variance in the final decision to commit. CONCLUSIONS: These results suggest that psychiatrists in Ontario rely primarily on legally mandated factors (i.e., psychosis and dangerousness) in making their decisions to commit, although a considerable amount of individual variation is also evident.

Self-report ratings and informants' ratings of personalities of depressed outpatients.

OBJECTIVE: This study sought to determine whether personality traits of depressed patients could be assessed similarly by informants and self-reports of the patients themselves. METHOD: Forty-six depressed outpatients completed the self-report (first-person) version of the Revised NEO Personality Inventory and nominated informants who knew them well to complete the third-person version of that instrument. RESULTS: Agreement between the self-ratings and informants' ratings on the five factors of the inventory--neuroticism, extraversion, openness-to-experience, agreeableness, and conscientiousness--was high. The only significant difference between the self-ratings and informants' ratings was on the extraversion scale, where the patients rated themselves as significantly more introverted than did the informants. CONCLUSIONS: Informants' ratings of personality are similar to self-report ratings of depressed patients. Depressed mood may not influence the self-report of personality traits.

Antidepressant-induced sexual dysfunction during treatment with moclobemide, paroxetine, sertraline, and venlafaxine.

BACKGROUND: Recent reports suggest that adverse effects on sexual function occur in up to 50% of patients who are treated with selective serotonin reuptake inhibitor (SSRI) antidepressants. Previously cited low rates were more likely a function of underreporting than underoccurrence. There is less evidence about rates of dysfunction with serotonin-norepinephrine reuptake inhibitor (SNRI) and reversible inhibitor of monoamine oxidase A (RIMA) antidepressants. The purpose of this report is to evaluate disturbances in sexual drive/desire and arousal/orgasm in 107 patients who met criteria for major depressive disorder and received treatment with either moclobemide, paroxetine, sertraline, or venlafaxine. METHOD: All consenting eligible patients who met DSM-IV criteria for major depressive disorder completed the Sexual Functioning Questionnaire, version 1 (SFQ) and were assessed using the 17-item Hamilton Rating Scale for Depression (HAM-D) prior to and after 8 or 14 weeks of antidepressant therapy. Analyses were carried out to examine the effect of gender, drug type, pretreatment level of sexual dysfunction, and drug response on reported sexual dysfunction. RESULTS: Compared with women, men experienced a significantly greater level of drug-related impairment in drive/desire (p < .05), whereas there were no statistically significant differences in levels of arousal/orgasm impairment between men and women. The reported impairment in drive/desire items for men ranged from 38% to 50% and from 26% to 32% for women. No differences were found across the 4 antidepressants in men, whereas in women, rates of dysfunction were generally higher with sertraline and paroxetine, but only significantly so in comparison with moclobemide on some measures (p < .03). Rates of sexual dysfunction with venlafaxine tended to fall between those of SSRIs and the RIMA agent. An unexpected relationship was found between favorable drug response and a decreased level of drug-induced sexual dysfunction. CONCLUSION: Antidepressant-induced sexual dysfunction occurs in approximately 30% to 70% of patients who are treated with sertraline or paroxetine. Lower rates are reported with moclobemide and venlafaxine. Clinicians should evaluate the various aspects of sexual dysfunction before and during antidepressant therapy.

MALDI-TOF MS analysis of a library of polymerizable cyclodextrin derivatives.

Polymerizable cyclodextrin derivatives (PCDs) have been proposed as candidates for use in dental therapeutics (Bowen, 1996; Bowen and Reed, 1997). Here, PCD "libraries" were synthesized by quasi-random reactions of 6 moles of methacrylic anhydride plus 6 moles of cyclic glutaric anhydride per mole of beta-cyclodextrin (BCD) in solution. BCD has 21 reactive sites on each of its molecules. These proportions were based on probability calculations, which predicted that the products should have a minimum of 2 polymerizable substituents and acidic ligand groups on practically every one of the diverse product molecules. Matrix-assisted laser desorption/ionization (MALDI) time of flight (TOF) mass spectrometry (MS) gave valuable information regarding the masses of molecular ions representing the molecules that made up the PCD libraries. For the MALDI-TOF MS analyses, small samples were analyzed by the successive application of 3 solutions to the sample holder: the matrix in acetone, the products in water, and sodium trifluoroacetate in water. The resulting spectra had > 40 envelopes of mass peaks above background. The ionic-abundance peak heights had quasi-Gaussian configurations, with central peaks having masses in the neighborhood of 2000 g/mol (Daltons). Regardless of structural permutations within each peak, the range of these peaks was between about 1500 g/mol and 2900 g/mol. This range of masses was in accord with, but perhaps somewhat more narrow than, that predicted by the statistical method, which was based on equal reactivity of all hydroxyl groups. Analysis by MALDI-TOF MS gave valuable data regarding the masses, structures, and characteristics of the products formed and provided unanticipated information to facilitate improvements in future PCD syntheses.

Personality and symptom profiles of the angry hostile depressed patient.

Fava, Rosenbaum, McCarthy, Pava, Steingard and Bless (1991) have recently proposed the existence of a subtype of depressed patients who experience anger attacks. The aim of this study was to assess if depressed patients categorized as high angry hostile have symptoms and personality profiles distinct from depressed patients categorized as low angry hostile. From a sample of 125 depressed outpatients, 26 patients were classified as high angry hostile and 25 patients as low angry hostile. The symptom profiles of these tow groups were remarkably similar, with the high angry hostile patients exhibiting more interpersonal sensitivity. The high angry hostile patients were rated as less interpersonally agreeable and less conscientious than low angry hostile patients. These results provide only partial support for the angry hostile subtype of depression.

Sexual dysfunction before antidepressant therapy in major depression.

BACKGROUND: Decreased sexual interest and function both occur as a consequence of antidepressant medication use, and are especially associated with serotonin reuptake inhibitors (SRIs). However, few investigators have reported the base rate for disturbances in sexual desire, arousal and orgasm or ejaculation in patients with major depression (MD) prior to antidepressant treatment. The purpose of this report is to define the frequency of sexual dysfunction (SD) in 134 patients with MD and examine the relationship between SD and demographic, clinical and personality variables. METHOD: A consecutive series of 55 male and 79 female MD patients diagnosed by SCID-DSM IV assessment completed a series of psychometric measures including a Sexual Function Questionnaire, which asked about change in sexual interest and function as well as sexual activity during the preceding month. RESULTS: Only 50% of women and 75% of men reported sexual activity during the preceding month. Over 40% of men and 50% of women reported decreased sexual interest. Reduced levels of arousal were more common in both men and women (40-50%) than ejaculatory or orgasm difficulties (15-20%). In women, problems with arousal and orgasm correlated with higher neuroticism and lower extraversion. There was no relationship between SD and personality measures in men. While age at onset of depression and number of prior episodes showed a modest correlation with SD measures, there were no correlations with severity of depression or specific symptoms clusters. LIMITATIONS AND CONCLUSIONS: Although limited by a relatively small sample of drug free patients with MD, and by the absence of a non-depressed comparison sample, these results emphasize the importance of factors beyond specific drug effects in the assessment of antidepressant related sexual dysfunction.

Bipolar disorder, unipolar depression and the Five-Factor Model of personality.

We examined differences between personality characteristics of euthymic bipolar disorder patients (BD) (n = 34) and recovered unipolar depressed patients (UD) (n = 74) using the taxonomy of the Five-Factor Model of personality (FFM) as measured by composite scales derived from the NEO Personality Inventory (NEO PI) and the revised NEO PI (NEO PI-R). Euthymic BD patients scored significantly higher on the Openness (O) dimension and the Positive Emotions facet of the E dimension than did recovered UD patients. For O, euthymic BD patients scored higher on the Feelings facet. These results suggest not only that euthymic BD patients are more likely to experience positive affects than recovered UD patients, but also that euthymic BD patients are more receptive to their positive and negative feelings than are recovered UD patients.

Differential pharmacological treatment response in high angry hostile and low angry hostile depressed patients: a retrospective analysis.

Fava et al., Am. J. Psychiatry 150 (1993)1158-1163, have recently proposed the existence of a sub-type of depressed patients who experience anger attacks. These investigators hypothesized that patients who experience anger attacks will respond better to a specific selective serotonin reuptake inhibitor (SSRI) medication than will depressed patients who do not experience anger attacks. Using a non-randomized, archival treatment methodology, 158 patients were classified as either high angry hostile (n = 83) or low angry hostile (n = 75). These patients had been treated with either a primarily noradrenergic reuptake inhibitor (desipramine) a SSRI (sertraline or paroxetine), or the combined serotonin and norepinephrine reuptake inhibitor (SNRI), venlafaxine. A 2 (high angry hostile/low angry hostile) x 3 (medication type) analysis of variance (ANOVA) was non-significant, indicating no differential treatment effects.

Sirenomelia: urological abnormalities in a surviving mermaid.

We report on a surviving four-year-old female with sirenomelia. She was born with the features of fused lower extremities, imperforate anus, colon atresia, pelvic and sacral dysplasia. Despite these severe anomalies, she had functional renal units. Maldevelopment of the genitourinary tract in patients with severe variant of caudal regression syndrome is usually incompatible with life. The case report includes the most current imaging studies of her unusual pelvic anomalies which poses a reconstructive challenge to the pediatric surgeon.

Determination of double bond conversion in dental resins by near infrared spectroscopy.

OBJECTIVES: This study determined the validity and practicality of near infrared (NIR) spectroscopic techniques for measurement of conversion in dental resins. METHODS: Conversion measurements by NIR and mid-IR were compared using two techniques: (1) The conversion of 3mm thick photopolymerized Bis-GMA/TEGDMA resin specimens was determined by transmission NIR. Specimens were then ground and reanalyzed in KBr pellet form by mid-IR. (2) As further verification, thin resin films were photocured and analyzed by mid-IR. Multiple thin films were then compressed into a thick pellet for examination by NIR. RESULTS: Conversion values obtained by NIR and mid-IR techniques did not differ significantly. A correction for changing specimen thickness due to polymerization shrinkage was applied to NIR conversion measurements since an internal standard reference peak was not employed. Sensitivity of the NIR technique was superior to those based on the mid-IR. SIGNIFICANCE: The nondestructive analysis of conversion in dental resins by NIR offers advantages of convenience, practical specimen dimensions and precision compared with standard mid-IR analytical procedures. Because glass is virtually transparent in the NIR spectrum, this technique has excellent potential for use with filled dental resins as well.

The effect of two initiator/stabilizer concentrations in a metal primer on bond strengths of a composite to a base metal alloy.

This study examined the effect of three additives, amine, peroxide and stabilizer, in two concentrations in a metal primer on the adhesion between a cast metal alloy and a resin composite using a 23 factorial statistical design. The additives, benzoylperoxide (BPO) used at 1% or 2% w/w and N,N-dimethyl-p-toluidine (DMPT) at 0.5% or 1.8% w/w are polymerization initiators. The third additive, butylated hydroxytoluene (BHT) at 0.01% or 0.03% w/w, is used as a stabilizer. BPO and BHT were dissolved in an acetone solution containing 20% of the adhesive resin pyromellitic glyceroldimethacrylate (PMGDM). DMPT was in a separate acetone solution. Equal portions of each solution were mixed and applied to a sandpaper-abraded, air-blasted nickel-chrome alloy. Bonding resin and composite were applied over the primer and stored overnight in water. Bond strengths were determined by shearing the composite from the metal at a cross head speed of 0.5 mm/min. Increasing the concentration of BPO caused a statistically significant increase in bond strength. A 3-way analysis of variance (ANOVA) at p<0.05 showed that, of the interactions, only the one between DMPT and BPO was significant, with lower concentrations of DMPT being less sensitive to changes in BPO concentration.