Noninvasive evaluation of swallowing sound is an effective way of diagnosing feeding maturation in newborn infants.

AIM: Despite extensive research, there is still controversy regarding the time at which sucking and swallowing functions mature in preterm infants. This study aimed to evaluate maturation using the noninvasive method of swallowing sound. METHODS: We compared 52 preterm infants of between 27 and 36 weeks' gestational age with a control group of 42 healthy full-term infants. Feeding performance was based on swallowing data collected during two-minute audio recordings. The following variables were generated for each evaluation: total number of swallows, total number of rhythmic swallows, total number of resting intervals, average time between resting intervals, average time between swallows, average time between rhythmic swallows, maximum number of rhythmic swallows and volume of milk ingested. The dependency of the variables on postmenstrual age was also investigated. RESULTS: The volume of milk ingested by the preterm infants and the maximum number of rhythmic swallows were positively correlated with postmenstrual age (PMA). The preterm infants reached the 10th percentile of the control infants at 34-35 weeks' PMA and were not significantly different from the control infants at 38-40 weeks' PMA. CONCLUSION: Swallowing sound can be used to assess feeding maturation in preterm infants during neonatal intensive care unit follow-up.

Activation properties of trigeminal motoneurons in participants with and without bruxism.

In animals, sodium- and calcium-mediated persistent inward currents (PICs), which produce long-lasting periods of depolarization under conditions of low synaptic drive, can be activated in trigeminal motoneurons following the application of the monoamine serotonin. Here we examined if PICs are activated in human trigeminal motoneurons during voluntary contractions and under physiological levels of monoaminergic drive (e.g., serotonin and norepinephrine) using a paired motor unit analysis technique. We also examined if PICs activated during voluntary contractions are larger in participants who demonstrate involuntary chewing during sleep (bruxism), which is accompanied by periods of high monoaminergic drive. In control participants, during a slowly increasing and then decreasing isometric contraction, the firing rate of an earlier-recruited masseter motor unit, which served as a measure of synaptic input to a later-recruited test unit, was consistently lower during derecruitment of the test unit compared with at recruitment (ΔF = 4.6 ± 1.5 imp/s). The ΔF, therefore, is a measure of the reduction in synaptic input needed to counteract the depolarization from the PIC to provide an indirect estimate of PIC amplitude. The range of ΔF values measured in the bruxer participants during similar voluntary contractions was the same as in controls, suggesting that abnormally high levels of monoaminergic drive are not continually present in the absence of involuntary motor activity. We also observed a consistent "onion skin effect" during the moderately sized contractions (<20% of maximal), whereby the firing rate of higher threshold motor units discharged at slower rates (by 4-7 imp/s) compared with motor units with relatively lower thresholds. The presence of lower firing rates in the more fatigue-prone, higher threshold trigeminal motoneurons, in addition to the activation of PICs, likely facilitates the activation of the masseter muscle during motor activities such as eating, nonnutritive chewing, clenching, and yawning.

Clinical study on the comparison of masticatory efficiency and jaw movement before and after temporomandibular disorder treatment.

In this clinical study, pre- and post-rehabilitation changes in intraborder mandible movements, chewing cycles, masticatory efficiencies, and borders of the chewing area of patients with unilateral muscular disorders (MD) (n = 20) or unilateral disc derangement disorders (DDD) (n = 20) of temporomandibular disorder (TMD) were observed and compared with healthy individuals with full dentition (n = 20) (48 female, 12 male; mean age: 28). The MD patients received stabilization splints and the DDD patients, anterior positioning splints for six weeks. Symptoms, such as muscle pain, TMJ pain, headache, chewing difficulty, and maximum mouth opening, showed significant improvements after splint therapy for both MD (p = 0.000) and DDD (p = 0.000) patients, but lateral excursion and protrusion were not significantly changed (p > 0.05). Chewing efficacy and chewing cycles improved significantly (p < 0.05) in both the MD (p < 0.05) and DDD (p < 0.05) groups, but only the MD group was comparable to the control group after treatment. Pre- and post-rehabilitation chewing cycles along the frontal plane on both sides in the MD group were similar to the control group. Considering the majority of the improvements in the diagnostic measures, patients with MD and DDD may benefit from occlusal splint therapy.

Masticatory performance and mandibular movement patterns of patients with natural dentitions, complete dentures, and implant-supported overdentures.

The aim of this study was to compare quantitatively the masticatory performance of patients with overdentures supported by two implants, conventional complete dentures, and natural dentitions. Each patient was asked to chew a gelatin cube. The collected remains of the test food (gelatine cube) were fractioned by a sieving procedure and weighed. Maximum mouth opening and masticatory area were measured using kinesiography. There were statistically significant differences among groups with respect to masticatory performance using a 3.15-mm-diameter sieve (P < .001) and 0.5-mm-diameter sieve (P < .001), masticatory area (P = .019), and maximum mouth opening (P < .001). Increasing retention of a mandibular complete denture with two implants improved masticatory performance.

Comparison of alternative adhesive cementation concepts for zirconia ceramic: glaze layer vs zirconia primer.

PURPOSE: Zirconia-based ceramics offer strong restorations in dentistry, but the adhesive bond strength of resin cements to such ceramics is not optimal. This study evaluated the bond strength of silane/adhesive/resin cement and zirconia primer/resin cement combinations on non-glazed and glazed zirconia surfaces before and after aging. MATERIALS AND METHODS: Disk-shaped zirconia ceramic specimens (diameter: 8 mm; thickness: 2 mm) (N = 80, n = 10 per group) were randomly divided into 2 groups. While half of the specimens received one coat of glaze and were later finished by grinding, the other half was only ground using 1200-grit silicone carbide abrasives under water. The glazed specimens were then conditioned with 9.5% HF acid gel for 60 s, rinsed with water for 90 s, and neutralized. The glazed and non-glazed specimens were further divided into two groups. Two resin cements, namely, Variolink II and Multilink Automix were adhered onto the zirconia surfaces with their corresponding adhesive systems. In the Variolink II group, zirconia surfaces were silanized (Monobond-S), and adhesive resin (Heliobond) was applied and photopolymerized. In the Multilink Automix group, one coat of Metal/Zirconia Primer was applied with a microbrush, left to react for 180 s, and dried using oil-free air. Half of the specimens in each cement group were subjected to 5000 thermocycles (5°C to 55°C) and the other half was kept in the dark for 24 h at 37°C prior to testing. Specimens were mounted in the jig of the universal testing machine, and force was applied to the ceramic/cement interface until failure occurred (1 mm/min). After evaluating all debonded specimens under SEM, the failure types were defined as either "adhesive" with no cement left on the zirconia (score 0) or "mixed" with less than half of the cement left on the surface with no cohesive failure of the substrate (score 1). Data were analyzed using three-way ANOVA and Dunnett-T3 post-hoc tests. RESULTS: Application of a glaze layer significantly improved the bond strength in the silane/adhesive/Variolink II group (p < 0.05), but no significant effect was found in the zirconia primer/Multilink Automix group (p > 0.05) (three-way ANOVA). Interaction terms were also significant (p < 0.05) (Dunnett-T3). Thermocycling did not decrease the results significantly in any of the groups (p > 0.05). Failure analysis revealed exclusively adhesive failures (score 0: 40 out of 40) in the non-glazed groups, but predominantly mixed failures (score 1: 34 out of 40) in the glazed groups. CONCLUSION: The silane (Monobond S)/adhesive (Heliobond)/Variolink II resin cement combination benefitted from glazing the zirconia surface, but the zirconia primer/Multilink Automix resin cement combination alone also provided sufficient bond strength to zirconia.

Pilot study of unidirectional E-glass fibre-reinforced composite resin splints: up to 4.5-year clinical follow-up.

OBJECTIVES: This prospective clinical pilot study evaluated the performance of fibre-reinforced-composite resin (FRC) splints on mandibular anterior teeth. METHODS: Between June-2003 and January-2008, 19 patients (7 females, 12 males, 45-72 years old) from a group of consecutive patients who completed periodontal therapy received E-glass FRC splints (everStick Perio, StickTech) in combination with two types of flowable and restorative resin-composites (Filtek Flow, Filtek Supreme, n=11; Tetric Flow, Tetric-Ceram, n=8). Only patients with vital teeth, presenting mobility of grade 3, having at least one canine with no mobility on both sides of the dental arch were assigned for a splint therapy. The patients were recalled for periodical follow-up controls first at 6 months and thereafter annually. The evaluation protocol involved technical failures [chipping, debonding or fracture (tooth/restoration)] and biological failures (caries)]. Periodontal pocket depth (PPD) and clinical attachment level (CAL) were measured 6 months after splinting and annually. Six sites were measured for each natural tooth at the mesiobuccal, buccal, distobuccal, distolingual, lingual and mesiolingual sites. RESULTS: All splints were applied from canine to canine in the mandible. In total, 5 recalls were performed and no drop-out was experienced. One partial debonding of the FRC splint with Tetric Flow/Tetric-Ceram combination was observed after 40 months. No caries was found around any of the splints and no teeth had to be extracted until the final follow up. The splinted teeth were found to be vital in the vitality tests. Overall survival rate was 94.8% (Kaplan-Meier). The survival rate was not significantly affected by the composite type (Filtek-Flow/Filtek Supreme: 100%, Tetric Flow/Tetric Ceram: 96% (p=0.92) [Kaplan-Meier, Log Rank (Mantel-Cox) (CI=95%)]. Hazard ratio for Tetric Flow/Tetric Ceram group was 0.05 (95% CI) and for Filtek Flow/Filtek Supreme group 0.00 (95% CI). Whilst overall PPD measurements of the dentition ranged between 6 and 12 mm, the CAL measurements ranged between 4.9 and 10mm at baseline. The mean PPD for the splinted teeth decreased from 8.9±1.8 mm to 5.2±1.2 mm, and CAL decreased from 7.2±1.6 mm to 4.6±1 mm at the end point. CONCLUSION: Direct tooth splinting with E-glass FRC material performed successfully up to 4.5 years. Periodontal status of the splinted teeth showed decreased PPD and CAL.

Bonded orthodontic retainer and fixed partial denture made with fiber reinforced composite resin.

Retention is the phase of orthodontic treatment which maintains teeth in their orthodontically corrected positions, following the cessation of active orthodontic tooth movement. Development of resin-impregnated, fiber-reinforced composite materials has provided the potential to develop new approaches for stabilizing teeth and replacing teeth conservatively. This case report describes the rehabilitation of a patient with orthodontic and prosthetic problems. The long-term behavior of glass fibers splint must be evaluated in clinical studies.

Oxidative stress-mediated myocardiotoxicity of ciprofloxacin and ofloxacin in juvenile rats.

In this study, evaluation of the myocardiotoxic effect potential of ciprofloxacin and ofloxacin in juvenile rats and the role of oxidative stress in heart toxicity was conducted. Doses (25 and 50 mg/kg) of each drug were administered to the rats for 1 week. Serum biochemical cardiotoxicity parameters and tissue malondialdehyde and nitric oxide levels were measured. All measured parameters were found elevated in the drug-treated rats, being the highest in the 50-mg/kg ofloxacin-treated rats. Ciprofloxacin and ofloxacin may cause myocardiotoxicity by inducing the oxidative stress in the heart, and nitric oxide is partly responsible for this toxicity.

Dental malpractice cases in Turkey during 1991-2000.

OBJECTIVES: Doctors can face punitive and legal consequences if patients are not satisfied with the medical treatment. The purpose of this study is to provide a database for dental malpractice cases in Turkey. METHODS: This study is based on the decisions of High Health Council (HHC) in medical malpractice cases. Between 1991 and 2000, 1548 decisions were made by the HHC. 14 (0.9%) of these decisions were related to dentistry. This study examines the 8 decisions under which the dentists are found to be at fault. RESULTS: As three of these cases are based on the same facts they are examined together. Of the dentists consulted on 11 decisions, nine were male and two were female. In four cases the HHC gave its expert opinion before the trial, in five cases during criminal trial and in two cases during compensation trial. In five cases patients received surgical treatment, in four cases prosthetic treatment and in two cases endodontic treatment. Nine of these treatments were carried out at private dental practice. In eight reported decisions negligence and inadequate treatment were identified. Most of negligence was caused during surgical intervention. In two cases, treatments resulted in death. CONCLUSIONS: Like all other medical staff dentists are under the obligation to comply with the legal rules in the country they practice. They also have to consider ethical principles as well as the acceptable standards and protocols of diagnosis and treatment.

Effect of different bonding agents on shear bond strengths of composite-bonded porcelain to enamel.

STATEMENT OF PROBLEM: The use of bonding agents in the luting procedure for porcelain laminate restorations to enamel is not clear. PURPOSE: This study evaluated the shear bond strength differences between an enamel-luting composite and a heat-pressed ceramic with 6 different bonding systems. MATERIAL AND METHODS: Seventy standardized heat-pressed IPS Empress ceramic discs (4-mm diameter, 3-mm height) were prepared. A vertical planar enamel-bonding surface was prepared on the buccal or lingual enamel of 70 freshly extracted sound human molars and premolars. The teeth were oriented to maintain a parallel relationship between the bonding plane and the shear loading axis of a universal testing machine. Tooth specimens were divided into 7 groups (n=10) comprising equal numbers of molars and premolars. The enamel surfaces of specimens in groups 1 through 6 were prepared with 1 of 6 bonding agents (Scotchbond Multi Purpose Plus, Heliobond, PQ1, SE Bond, Prime&Bond NT, and Prompt L-Pop). Finally, the specimens were luted to the ceramic discs with the composite cement (Opal Luting Composite). Ceramic discs in the seventh group (Control) were luted to the etched enamel with the composite cement without using bonding material. Enamel-ceramic specimens were kept in distilled water at room temperature for 30 days after cementation. All specimens were shear loaded axially in a universal testing machine with a crosshead speed of 0.05 mm/min until fracture. Shear bond strength was measured and recorded for each group in MPa. To determine the statistical significance of the differences between the mean shear bond strength values, a 1-way analysis of variance was used (alpha=.05). Post-hoc multiple comparisons were made with Duncan's multiple range analysis. Fractured surfaces of each specimen were also inspected with a stereomicroscope to evaluate failure modes. RESULTS: A 1-way analysis of variance revealed significant differences between the test groups (P=.00). Bond strength values (MPa) from the highest to the lowest were as follows: Prompt L-Pop, 25.46 +/- 5.6; Prime&Bond NT, 18.99 +/- 4.93; Heliobond, 17.28 +/- 4.0; SE Bond, 16.21 +/- 2.6; PQ1, 15.60 +/- 2.8; Scotchbond MPP, 14.82 +/- 2.4; and Control, 10.55 +/- 1.6. Duncan's multiple range post hoc analysis exhibited significant differences between the control group and the adhesive bonding agent groups (P<.05). There were also significant differences between the bonding agent groups (P<.05). Prompt L-Pop showed the highest bond strength values. CONCLUSION: Within the limitations of this study, bonding agents appear to have a strengthening effect on the shear bond strengths of the enamel/composite/porcelain interface of the materials tested. Bonding agents used in this study showed similar bond strength values except for Prompt L-Pop, which demonstrated the highest bond strength values.

In vivo and in vitro evaluation of occlusal indicator sensitivity.

STATEMENT OF PROBLEM: Indicators used to locate and eliminate occlusal disharmonies have not demonstrated specific sensitivity and reliability. PURPOSE: The sensitivity and reliability of articulating papers, foils, silk strips, and T-Scan systems used as occlusal indicators were investigated. The effect of saliva on the materials also was determined. MATERIAL AND METHODS: In the in vitro part of the study, a test model (mounted in an articulator and in a universal testing machine) was established with the use of maxillary and mandibular dentate casts. Articulating papers, foils, silk strips, and the T-Scan system were used to examine the loss of sensitivity of the recording materials after 3 consecutive strokes. The differences in the contact points of the test model determined by each of the recording materials were evaluated both in the articulator and in a universal testing machine. In the in vivo part of the study, occlusal contact recordings of 3 subjects were made before and after drying their mouths. The significance of the differences between the strokes repeated more than once was evaluated with the Friedman 2-way analysis of variance and Kruskal-Wallis tests. To examine the effect of the oral environment, the Wilcoxon matched-pairs signed-ranks test was applied. In all statistical analyses, the level of significance was alpha=.05. RESULTS: The results demonstrated significant differences in the sensitivity of the recording materials tested (P<.001). The sensitivity of all recording materials decreased after multiple use (P<.001), and the loss of recording accuracy was significant (P<.001). All recording materials except the T-Scan were affected by the presence of saliva (P<.01). CONCLUSION: Within the limitations of this study, the results indicated that multiple use of the recording materials tested may lead to inaccurate occlusal analysis results. It is recommended that the recording materials be used only once and that the teeth be dry during occlusal analysis.

Alternative method for connecting a removable gingival extension and fixed partial denture: a clinical report.

In terms of esthetics and hygiene, defects in the alveolar ridge can complicate the design and fabrication of fixed partial dentures. When missing anterior teeth are restored, it may be difficult to achieve a satisfactory appearance without the correction of soft tissue and alveolar defects. When surgical intervention is not an option, a removable gingival extension and fixed prosthesis may be considered. This clinical report describes the use of a custom-made pin system (rather than intra- or extra-coronal attachments) to esthetically connect a removable gingival extension to a fixed partial denture.

Prosthetic rehabilitation of extremely worn dentitions: case reports.

The stomatognathic system is a complicated structure, and patients usually adapt to their existing vertical dimension of occlusion. Therefore, prosthetic rehabilitation of decreased vertical dimension of occlusion should be considered only when dictated by esthetic or functional requirements. If the loss of vertical dimension is significant, provisional prostheses should be used before the final prosthesis to prevent tension or pain in the temporomandibular joints and the muscles as the patient adapts to the new dimensions. Acrylic resin provisional prostheses were used for three patients before the final prosthesis was fabricated with the restored vertical dimension of occlusion. The period of use varied, depending on the patient's individual adaptive ability. The important aspect is to find the most comfortable position for the patient.