Microhardness of Calcium-enriched Mixture Cement and Covering Glass Ionomers after Different Time Periods of Application.

Introduction: Various studies have recommended using calcium-enriched mixture (CEM) cement in different endodontic treatments, including vital pulp therapy. However, possible reciprocal effects of the covering glass ionomer cement (GIC) on their mechanical properties have not been yet investigated in detail. The current research aimed to experimentally evaluate the surface microhardness of CEM cement and the covering GICs after different application/testing times. Materials and Methods: Using stainless steel moulds (8×4×4 mm), CEM cement samples were prepared (n=120) and randomly divided into 12 experimental groups (n=10). CEM cement with thickness of 4 mm was inserted into the moulds, and the remaining spaces were filled with self-cured or light-cured resin-modified GICs at three-time intervals; immediate, in 15 min and after 24 h. Then, the samples were incubated for one and seven days. Using a Vickers microhardness tester, the microhardness of CEM and GICs was measured. The data were analyzed using two-way ANOVA and Tukey's test, and the significance level was set at 5% (P<0.05). Results: The reciprocal effects of the type/time of application of GICs on the surface microhardness of CEM cement or GICs were statistically significant (P<0.001). The surface microhardness of CEM cement and both covering GICs significantly increased over time and in seven-day samples was significantly higher than in one-day samples (P<0.05). Conclusions: Low surface microhardness of CEM/GICs in short-term (24 h) seems transient; and appears to be compensated over a longer period (i.e. 7-day). Therefore, using GICs adjacent to CEM cement in single-visit restorative treatments may be advocated.

Postendodontic Pain after Pulpotomy or Root Canal Treatment in Mature Teeth with Carious Pulp Exposure: A Multicenter Randomized Controlled Trial.

This equivalence, randomized, clinical trial aimed to compare the postoperative pain of root canal therapy (RCT) with pulpotomy with mineral trioxide aggregate (PMTA) or calcium-enriched mixture (PCEM) in permanent mature teeth. In seven academic centers, 550 cariously exposed pulps were included and randomly allocated into PMTA (n = 188), PCEM (n = 194), or RCT (n = 168) arms. Preoperative "Pain Intensity" (PI) on Numerical Rating Scale and postoperative PIs until day 7 were recorded. Patients' demographic and pre-/intra-/postoperative factors/conditions were recorded/analysed. The arms were homogeneous in terms of demographics. The mean preoperative PIs were similar (P=0.998), the mean sum PIs recorded during 10 postoperative intervals were comparable (P=0.939), and the trend/changes in pain relief were parallel (P=0.821) in all study arms. The incidences of preoperative moderate-severe pain in RCT, PMTA, and PCEM arms were 56.5%, 55.7%, and 56.7%, which after 24 hours considerably decreased to 13.1%, 10.6%, and 12.9%, respectively (P=0.578). The time span of endodontic procedures was statistically different; RCT = 69.73, PMTA = 35.37, and PCEM = 33.62 minutes (P < 0.001). Patients with greater preoperative pain, symptomatic apical periodontitis, or presence of PDL widening suffered more pain (P=0.002, 0.035, and 0.023, resp.); however, other pre-/intra-/postoperative factors/conditions were comparable. Pulpotomy with MTA/CEM and RCT demonstrate comparable and effective postoperative pain relief.

Test-retest & Inter-rater Reliability of Persian Version of Pediatric Balance Scale in Children with Spastic Cerebral Palsy.

OBJECTIVES: Children affected with spastic cerebral palsy suffering a lot of movement and balance difficulties. Balance is one of the essential variables of movement, which facilitates functional skills. The main purpose of this study was inter-rater & test-retest reliability of Pediatric Balance Scale (PBS) in children with spastic cerebral palsy. MATERIALS & METHODS: In this analytical-descriptive research performed in the rehabilitation centers, south of Tehran, Iran in 2016, psychometric method was used. For investigating the inter-rater reliability, two examiners performed the scale simultaneously with 50 children with spastic cerebral palsy. Moreover, to investigate the test-retest reliability, the scale was implemented by one examiner, in two different sessions, among 50 children with spastic cerebral palsy. There was a two-week period between the first and the second session. RESULTS: The inter-rater reliability (ICC=0.99), as well as the test-retest reliability (ICC=0.99), was quite high. Standard Error of Measurement (SEM) was acceptable for either test-retest or inter-rater reliability. CONCLUSION: PBS is appropriate for measuring functional balance in children with spastic cerebral palsy with mild to moderate motor impairment.

Top-Down Auditory Plasticity: Acceptable Noise Level Predicts and Reflects the Effect of Perceptual Learning in Experience-Induced Plasticity.

OBJECTIVE: In the auditory system, tinnitus and superior speech perception in noise are examples of negative and positive plasticity that can result from sensory neural hearing loss and life experiences dealing with more complex stimuli and learning, respectively. The main objective of this study was to determine the relationship between acceptable noise level (ANL) values and perceptual learning in individuals exposed to unavoidable occupational noise. MATERIALS & METHODS: Here we document a form of plasticity in top-down auditory pathways through the measurement of the acceptable noise level in 60 adults, 27 females and 33 males, with normal hearing (Amiraalam state Hospital, Tehran, Iran 2016). Individuals were assigned to one of two groups: those with and without the occupational experience of speech perception in noise. RESULTS: The test group had statistically significant lower acceptable noise level and significantly higher background noise level scores compared with the control group. CONCLUSION: Using acceptable noise level, we attributed differences in individuals' abilities to tolerate varying amounts of background noise and speech perception in noise function to the auditory efferent system. Working in crowded locations due to job nature can influence differences in speech perception in noise function.

The Effect of the Timing of Umbilical Cord Clamping on Hemoglobin Levels, Neonatal Outcomes and Developmental Status in Infants at 4 Months Old.

OBJECTIVES: Delayed umbilical cord clamping (DCC) increases blood transfer to newborns. Hence we investigated the effect of the timing of DCC on hemoglobin levels, neonatal outcomes and developmental status in infants at four months old. MATERIALS & METHODS: This clinical trial examined infants born to 400 pregnant women immediately upon birth and at the age of four months in Isfahan, central Iran in 2016. A table of random numbers was used to randomly allocate the newborns to intervention group with a 90-120-sec delay in umbilical cord clamping and the control group with a clamping delay of below 60 sec, and blood samples were taken from their umbilical cords. The Ages and Stages Questionnaire was used to evaluate the infants' developmental status. RESULTS: Umbilical cord hemoglobin was significantly higher in the intervention group compared to in the controls (P=0.024). No significant differences were observed between the two groups in terms of neonatal complications except neonatal jaundice was significantly more common in the intervention group (P=0.025), although the need for phototherapy was not different between the groups. Overall, no significant differences were observed between the two groups in terms of developmental status at four months old; however, the infants had better problem-solving skills in the DCC group (P=0.015). CONCLUSION: Despite elevating hemoglobin, DCC has no effects on infant development except in terms of problem-solving skills. Further studies are recommended on the effects of DCC on infant development.

Effect of Ingested Liquids on Color Change of Composite Resins.

OBJECTIVES: Color change of composite restorations is well known to dentists. However, the effect of commonly consumed drinks on discoloration of composite resins has yet to be determined. This study sought to assess the color change of a nanofilled (Premise) and a flowable composite resin (Premise flowable) following simulated consumption of tea, cola, iron drops and multivitamin syrup. MATERIALS AND METHODS: Forty disk-shaped specimens (7 mm in diameter and 2 mm thick) were fabricated from each composite resin. The baseline color values were measured according to the CIE L*a*b* system using digital imaging. The specimens of each restorative material were randomly divided into five groups (eight each) according to the storage media namely tea, cola, iron drops, multivitamin syrup or distilled water (control). The specimens were immersed in staining solutions for three hours daily over a 40-day test period. Following this, the color change values (ΔE*) were calculated. For statistical analyses, the color differences were analyzed using two-way ANOVA and Tukey's test (P< 0.05). RESULTS: There was no significant difference in ΔE* values between the two types of composite resins (P>0.05). In both composite materials, the difference among the solutions was not significant (P>0.05). CONCLUSION: Under the tested experimental conditions, both restorative materials were susceptible to discoloration by all four staining solutions. The color change values were not related to the solution or the type of material used.