Mitigating the Effect of Pain Severity on Activity and Disability in Patients with Chronic Pain: The Crucial Context of Acceptance.

OBJECTIVE: The purpose of this study was to examine the effect of pain severity on activity levels and physical disability in the context of high pain acceptance. We hypothesized that pain acceptance moderates the effect of pain severity on general activity and physical disability, such that at higher levels of acceptance, the deleterious effect of pain is mitigated. METHODS: Two hundred seven patients with chronic pain were recruited from three clinics in a large southwestern military treatment facility. Participants completed an anonymous self-report battery of standardized measures, including the Chronic Pain Acceptance Questionnaire, modified Oswestry Disability Index, and Pain Severity and General Activity subscales of the West Haven-Yale Multidimensional Pain Inventory. RESULTS: Chronic pain acceptance was found to significantly moderate relations between pain severity and general activity (b = 0.0061, t(198) = 2.75, P = 0.007, 95% confidence interval [CI] = 0.002 to 0.011) and pain severity and disability (b = 0.036, t(193) = -2.564, P = 0.011, 95% CI = -0.063 to -0.008). In the context of higher acceptance, the negative effect of pain on activity and disability appeared reduced. Conversely, in the context of low acceptance, the effect of pain on disability appeared accentuated at all levels of pain severity. CONCLUSIONS: Higher acceptance mitigated both activity level and disability in a military-affiliated clinical sample of patients with chronic pain. Results further establish the role of acceptance in relation to functioning in a unique sample of people with chronic pain. These findings have implications for understanding and enhancing functioning in chronic pain populations.

Effect of needle design on pain from dental local anesthetic injections.

The purpose of this randomized, double-blind clinical study was to evaluate the effectiveness of a larger-bore compared with a standard-bore dental local anesthetic needle of the same gauge in reducing pain during inferior alveolar (IA) and long buccal (LB) nerve block injections. Twenty active duty military or Department of Defense beneficiaries undergoing dental treatment were anesthetized using a split-mouth design with 4 anesthetic dental injections. Both sides of the mouth received IA nerve block and LB nerve injections, one using the 27-gauge large-bore Septoject XL needle and other using a 27-gauge standard-bore Septoject needle. Patients rated the pain experienced with each method using a visual analogue scale (VAS). The IA injection mean VAS score and standard deviation were 38.9 ± 22.7 mm and 37.1 ± 22.4 mm, respectively, for the larger and standard-bore needles. The LB injection mean VAS score and standard deviation were 33.5 ± 22.8 mm and 35.1 ± 19.6 mm, respectively, for the larger and standard-bore needles. The data were analyzed with a paired t test (α = .05). No significant difference was found between the IA (P = .70) or LB injections (P = .73). The use of a larger-bore 27-gauge needle did not reduce pain on injection compared with the standard-bore 27-gauge needle.

Physical properties of a new sonically placed composite resin restorative material.

A new nanohybrid composite activated by sonic energy has been recently introduced as a single-step, bulk-fill restorative material. The purpose of this study was to compare the physical properties of this new composite to various other composite restorative materials marketed for posterior or bulk-fill placement. The following physical properties were examined: depth of cure, volumetric shrinkage, flexural strength, flexural modulus, fracture toughness, and percent porosity. A mean and standard deviation were determined per group. One-way ANOVA and Tukey's post hoc tests were performed per property (α = 0.05). Percent porosity was evaluated with a Kruskal-Wallis/Mann-Whitney test (α = 0.005). Significant differences were found between groups (P < 0.001) per test type. Compared to the other composite restorative materials, the new nanohybrid composite showed low shrinkage and percent porosity, moderate fracture toughness and flexural modulus, and high flexural strength. However, it also demonstrated a relatively reduced depth of cure compared to the other composites.

Effects of cyclic loading and toothbrush abrasion on cervical lesion formation.

This study sought to determine the effect of cyclic loading and toothbrush abrasion (with and without abrasive slurries) on cervical lesion formation. The roots of extracted human third molars were embedded in acrylic resin, leaving 2 mm of root structure and crowns exposed. Teeth were divided into 6 groups (n = 10) with the following treatments: no treatment (control), cyclic load in distilled water, brushing with distilled water, cyclic load followed by brushing with distilled water, brushing with toothpaste slurry, and cyclic load followed by brushing with toothpaste slurry. Cyclic loading and toothbrushing machines subjected the teeth to 1.6 million cyclic loads and 30,000 brushing strokes, the equivalent of 4 years of function and brushing for an average patient. The teeth were scanned with a 3-dimensional optical profilometer to determine the volumetric loss of tooth structure. Load cycling had no significant effect on cervical tooth loss. Brushing with toothpaste resulted in significantly greater cervical tooth loss than brushing with water, which in turn was significantly greater than no treatment at all.

Volumetric wear of various orthotic appliance materials.

The purpose of this study was to compare the resistance to wear of six commonly used orthotic appliance materials. These materials were: SR Ivocap (Ivoclar Vivadent, Inc., Amherst, NY), Eclipse (Dentsply International, York, PA), ProBase (Ivoclar Vivadent), Valplast (Valplast International Corp., Oceanside, NY), Impak (CMP Industries LLC, Albany, NY), and Clearsplint (Astron Dental Corp., Lake Zurich, IL). Twelve cylindrical specimens of each material were fabricated per manufacturer instructions. Occlusal wear was simulated in a custom-made wear simulator with each specimen receiving four wear scars in a two-body wear simulation using a 1.5 mm tungsten-carbide tipped stylus at 40 newtons for 2500 cycles at 1 Hz, while immersed in 37 degrees C distilled water (n = 48). The specimens were evaluated before and after wear testing using a three-dimensional (3D) noncontact profilometer (Proscan 2000, Scantron Corp., Eagan, MN). A mean change in volume was determined for each orthotic material. Results found that Clearsplint material displayed the greatest amount of volume loss/wear, while SR Ivocap, Eclipse, and ProBase materials had the least amount of wear. Valplast and Impak performed more moderately. Based upon this wear knowledge, practitioners are able to more reliably choose the appliance material necessary for their various patients.