Evaluation of fissure sealing with a diluted composite sealant and an UV-light polymerized sealant after 36 months' observation

abstract – The idea of fissure sealing has found wide acceptance in caries prevention. The present investigation was initiated to evaluate the retention of a diluted composite material used as a fissure sealant, compared with the retention of an UV-light polymerized sealant. After an observation period of 3 years, it seems justified to assume that a diluted composite sealant is a fully acceptable alternative to an UV-light polymerized sealant, and the former material seemed to have some advantages: a simpler polymerization procedure, an apparently better wear resistance due to ceramic filler particles, and an easier recognition because of a slight discoloration.     

Effect of 2-years' use of chlorhexidine-containing dentifrices on plaque, gingivitis, and caries

abstract — Chlorhexidine digluconate in 0.1% and 0.4% concentrations was added to dentifrices to evaluate its effect on plaque formation, gingival conditions and caries in 73 dental students over a 2-year period. No differences were found in the P1 I and the G I indices between the active and the placebo dentifrices, but a possible effect on caries was demonstrated. Discolorations of anterior teeth and fillings were the only side effects observed.     

In vitro caries related to marginal leakage around composite resin restorations

The histology of caries-like lesions around composite resin restorations with and without marginal leakage has been studied. The lesions were generated from bacterial plaque growing in an in vitro system. Marginal leakage was prevented by an acid etch technique. Ground sections of the experimental teeth were studied by polarized light and microradiography. The caries lesions penetrated along conventional class V restorations with marginal leakage while restorations bonded to an acid etched enamel surface totally prevented this ingrowth.     

Overdosage of Piroxicam

Abstract A 54-year-old woman took an overdose of 1 800 mg piroxicam. She complained of nausea and abdominal pain. Endoscopy revealed multiple superficial ulcerations in the pyloric antrum and the first part of duodenum. There were no symptoms or signs from other organ system and recovery was uneventful. The highest serum concentration was 241.6 mg/1, which is about 30 times the usual therapeutic level of 5–10 mg/1.     

Chlorhexidine as a denture disinfectant in the treatment of denture stomatitis

abstract – In a double-blind study conducted on 53 wearers of complete dentures, application of 2 % chlorhexidine gluconate to the fitting surface of the maxillary denture for 2 weeks was found to produce a significant amelioration of inflamed tissues beneath the denture. Mycelium was eliminated in 90 % of the patients, as evaluated by palatal smears. Five weeks after the treatment was terminated the candida infection of the palatal mucosa was re-established in all but one of the patients, probably because disinfection of the maxillary denture did not effect a complete suppression of candida growth, neither in the palate nor in other sites of the oral cavity. It is concluded that chlorhexidine gluconate is an appropriate alternative to specific antimycotic drugs for the treatment of palatal can didiasis. However, until conclusive evidence has been produced that prolonged mouth-rinsing with chlorhexidine is biologically acceptable, it should be used primarily as a denture disinfectant, whereas specific antimycotic drugs should be used to eradicate candida residing on the oral mucosa.     

Reperfusion Arrhythmias: Role of Early Afterdepolarizations Studied by Monophasic Action Potential Recordings in the Intact Canine Heart During Autonomically Denervated and Stimulated States

Reperfusion Arrhythmias and Afterdepolarizations. Introduction: The precise mechanism of reperfusion arrhythmias is not established. The role of early afterdepolarizations (EADs) and triggered activity in the genesis of reperfusion ventricular arrhythmia was investigated. Methods and Results: Monophasic action potentials (MAPs) were recorded in the canine heart using Ag-AgCl contact electrodes from the left and right ventricular endocardium and the left ventricular epicardial border zone during 10 minutes of occlusion of the proximal left anterior descending coronary artery followed by 2 minutes of reperfusion. Ventricular arrhythmias during ischemia and reperfusion were studied in three autonomically varied groups. Group 1 (n = 8) had intact autonomic neural innervation; group 2 (n =8) had bilateral transection of ansae subclavii and vagi; and group 3 (n =8) underwent bilateral transaction of ansae subclavii and vagi with bilateral ansae subclavii stimulation during reperfusion. Ventricular fibrillation (VF) on reperfusion occurred in 2, 3, and 5 animals in the innervated, denervated, and sympathetically stimulated groups, respectively. Rapid ventricular tachycardia during ansae subclavii stimulation, antecedent to VF, occurred in 4 of 5 episodes in the sympathetically stimulated group. The frequency of premature ventricular complexes, couplets, and triplets on reperfusion was not significantly different among the three groups. Phase 2 or phase 3 EADs were noted during the acute ischemic phase in 6 of 8, 7 of 8, and 7 of S animals in the three groups, respectively (and persisted during reperfusion in the majority). Thus, these EADs were not a de novo phenomenon during reperfusion. Of the 72 MAP recording sites, only one demonstrated de novo phase 2 EADs during reperfusion. EADs disappeared during reperfusion in 6 animals (prior to the onset of VF in 4), and 5 dogs developed reperfusion VF without EADs being recorded. There was no direct correlation between tbe presence of EADs during repertusion and the development of VF. The prevalence and onset of reperfusion VT was not significantly different in tbe presence of sympathetic stimulation. Conclusion: This study demonstrates that EADs can be recorded in the majority of dogs during both ischemia and reperfusion and do not appear to be a major mechanism responsible for reperfusion ventricular tachycardia and VF.     

Marginal leakage with different composite restorative materials in vitro

In this preliminary study the degree of marginal leakage was assessed for different cavity designs using both ultra violet-curing and self-curing composite restorative materials and sealants. Butt joint restorations placed in etched and sealant primed cavities failed to prevent leakage. Both saucer-shaped and funnel-shaped cavities and cavities with rounded margins were able to prevent leakage when the restorations were bonded to etched and sealant primed peripheral enamel. Further, less than 1 mm of gingival enamel available for bonding seemed to be sufficient in most instances to prevent leakage.     

Correlation between Laser Fluorescence Readings and Volume of Tooth Preparation in Incipient Occlusal Caries In Vitro

Objective:  This study evaluated the correlation between laser fluorescence readings and the extent of incipient occlusal caries as measured by the volume of tooth preparation in vitro.
Materials and Methods:  One hundred and three permanent molars and premolars containing incipient occlusal pit-and-fissure caries and sound occlusal surfaces (1/4 of the sample, control) were selected. DIAGNOdent (KaVo Dental Corporation, Lake Zurich, IL, USA) readings were obtained according to manufacturer instructions. Caries was removed with 1/4 round burs in high speed. The volume of tooth preparation was measured using a surrogate measure based on the amount of composite needed to fill the preparations. Sensitivity and specificity using different cutoff values were calculated for lesions/preparations extending into dentin. The results were analyzed statistically.
Results:  The Pearson correlation for preparation volume and DIAGNOdent reading measurements was low ( r  = 0.285). Sensitivity and specificity of DIAGNOdent for detection of dentinal lesions were 0.83 and 0.60, and 0.66 and 0.73 for the cutoff values of 20 and 30, respectively.
Conclusions:  Within the limitations of this study, laser fluorescence measured with DIAGNOdent does not correlate well with extent of carious tooth structure in incipient occlusal caries.

CLINICAL SIGNIFICANCE

Clinicians should not rely only on DIAGNOdent readings to determine the extension of incipient occlusal caries.
( J Esthet Restor Dent 22:31–41, 2010)     

Image‐Integration of Intraprocedural Rotational Angiography‐Based 3D Reconstructions of Left Atrium and Pulmonary Veins into Electroanatomical Mapping: Accuracy of a Novel Modality in Atrial Fibrillation Ablation

DynaCT Cardiac Integration into Electroanatomical Mapping. Introduction: Exact visualization of complex left atrial (LA) anatomy is crucial for safety and success rates when performing catheter ablation of atrial fibrillation (AF). The aim of our study was to validate the accuracy of integrating rotational angiography‐based 3‐dimensional (3D) reconstructions of LA and pulmonary vein (PV) anatomy into an electroanatomical mapping (EAM) system. Methods and Results: In 38 patients (62 ± 8 years, 25 females) undergoing catheter ablation of paroxysmal (n = 19) or persistent (n = 19) AF, intraprocedural rotational angiography of LA and PVs was performed. The subsequent 3D reconstruction and segmentation of LA and PVs was transferred to the EAM system and registered to the EAM. The distances of all EAM points to corresponding points on the LA syngo® DynaCT Cardiac surface were calculated. Segmentation of LA with clear visualization of adjacent structures was possible in all patients. Also, the integrated segmentation of the LA was used to guide the encirclement of ipsilateral veins, which resulted in PV isolation in all patients. Integration into the 3D mapping system was achieved with a distance error of 2.2 ± 0.4 mm when compared with the EAM surface. Subgroups with paroxysmal and persistent AF showed distance errors of 2.3 ± 0.3 mm and 2.1 ± 0.4 mm, respectively (P = n.s.). Conclusion: Intraprocedural registration of LA and PV anatomy by contrast enhanced rotational angiography was feasible and accurate. There were no differences between patients with paroxysmal or persistent AF. Therefore, integration of rotational angiography‐based reconstructions into 3D EAM systems might be helpful to guide catheter ablation for AF. (J Cardiovasc Electrophysiol, Vol. 21, pp. 278–283, March 2010)