Martin Jean Koch

Mineral Trioxide Aggregate or Calcium Hydroxide Direct Pulp Capping: An Analysis of the Clinical Treatment Outcome

INTRODUCTION The use of mineral trioxide aggregate (MTA) might improve the prognosis of teeth after pulp exposure. The treatment outcome of teeth after direct pulp capping, either with mineral trioxide aggregate (MTA) or calcium hydroxide (controls), was investigated, taking into account possible confounding factors. METHODS One hundred forty-nine patients treated between 2001 and 2006 who received direct pulp capping treatment in 167 teeth met the inclusion criteria. Treatment was performed by supervised undergraduate students (72%) and dentists (28%). Assessment of clinical and radiographic outcomes was performed by calibrated examiners 12-80 months after treatment (median, 27 months). RESULTS One hundred eight patients (122 treated teeth) were available for follow-up (72.5% recall rate). A successful outcome was recorded for 78% of teeth (54 of 69) in the MTA group and for 60% of teeth (32 of 53) in the the calcium hydroxide group. The univariate analysis (generalized estimation equations model [GEE model] showed a significant difference in the success rate (odds ratio [OR], 2.36; 95% confidence interval [CI], 1.05-5.32; P = .04). In the multiple analysis (GEE model), the OR is marginally inside the nonsignificant range (OR, 0.43; 95% CI, 0.19-1.02; P = .05) when conspicuous confounding factors are stabilized (univariate analysis). Multiple analysis showed that teeth that were permanently restored >or=2 days after capping had a significantly worse prognosis in both groups (OR, 0.24; 95% CI, 0.09-0.66; P = .01). CONCLUSIONS MTA appears to be more effective than calcium hydroxide for maintaining long-term pulp vitality after direct pulp capping. The immediate and definitive restoration of teeth after direct pulp capping should always be aimed for.

Connexin 43 gene therapy prevents persistent atrial fibrillation in a porcine model

AIMS Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, and effective treatment of AF still remains an unmet medical need. AF is associated with atrial conduction disturbances caused by electrical and/or structural remodelling. We hypothesized that AF suppresses expression of the gap junction protein connexin (Cx) 43 and that Cx43 gene transfer to both atria would prevent persistent AF. The first aim of this study was to assess whether AF is associated with connexin remodelling in a porcine model. A strategy to suppress persistent AF by gene therapy was then developed and evaluated in vivo. METHODS AND RESULTS AF was induced in domestic pigs via atrial burst pacing, causing a 62.4% reduction in atrial Cx43 protein. Adenoviruses encoding for Cx43 (AdCx43) or green fluorescent protein (AdGFP) were injected into both atria, followed by epicardial electroporation to enhance transgene expression. Combining direct injection of adenoviruses with electroporation achieved GFP reporter gene expression in ∼50% of atrial cells in vivo. AdCx43-treated animals exhibited a 2.5-fold increase in atrial Cx43 protein content and did not develop persistent AF during the observation period of 14 days. In contrast, control animals developed persistent AF within 7.4 ± 0.5 days. Rapid ventricular heart rates during AF led to deterioration of cardiac function in control pigs but not in pigs treated with AdCx43. CONCLUSION Our results highlight the contribution of Cx43 to the pathophysiology of AF and demonstrate the viability of gene therapy for prevention of atrial arrhythmias.

Treatment outcome of mineral trioxide aggregate: repair of root perforations.

INTRODUCTION The use of biocompatible materials like mineral trioxide aggregate (MTA) may improve the prognosis of teeth with root perforations. METHODS The treatment outcome of root perforations repaired between 2000 and 2006 with MTA was investigated. Twenty-six patients received treatment with MTA in 26 teeth with root perforations. Treatment was performed by supervised undergraduate students (29%), general dentists (52%), or dentists who had focused on endodontics (19%). Perforation repair by all treatment providers was performed using a dental operating microscope. Calibrated examiners assessed clinical and radiographic outcome 12 to 65 months after treatment (median 33 months, 81% recall rate). Pre-, intra-, and postoperative information relating to potential prognostic factors was evaluated. RESULTS Of 21 teeth examined, 18 teeth (86%) were classified as healed. None of the analyzed potential prognostic factors had a significant effect on the outcome. CONCLUSIONS MTA appears to provide a biocompatible and long-term effective seal for root perforations in all parts of the root.

Enamel hypoplasia of primary teeth in chronic renal failure

Abstract Chronic renal failure (CRF) in the first years of life is associated with developmental defects of enamel in the permanent dentition. We investigated if CRF also affects the primary (deciduous) dentition. Thirty-one children with CRF on conservative treatment (n=12) or on renal replacement therapy (n=19) underwent dental inspection. In addition, 18 CRF children provided an exfoliated deciduous tooth for microscopic examination. Enamel defects were detected in a total of 12 children (31%), either clinically or microscopically. Of the 7 children affected clinically, 6 (19% of all examined) presented localized hypoplasia of the primary canines, which was found only in 3% of healthy control children: 1 patient had generalized pitted enamel hypoplasia. By microscopy, 5 of 10 primary canines examined showed enamel hypoplasia localized exclusively in enamel formed after birth. The ”birth line,” a visible structure within the primary enamel, was always present, which excludes a prenatal onset of the defects. Of the 12 patients with an enamel defect, 9 had a documented onset of CRF within the first 7 weeks of life. We conclude that renal disease leading to CRF may affect enamel formation of primary teeth in early postnatal life, resulting in lesions different from those observed in the secondary dentition.

Clinical evaluation of Helioseal F fissure sealant.

Abstract Unfilled resins are commonly in use as sealant material. In addition, there are filled sealants available. Helioseal F is a newly developed filled material with fluoride release. In this clinical trial, Helioseal F has been evaluated in one lower molar versus Delton opaque as an unfilled control in lower molars. After 12 months there were no significant differences in retention, porosities, and the number of clinically unacceptable margins between the materials. The complete retention was 30 out of 31 examined teeth for Delton and 28 out of 31 for Helioseal F. After 1 year of clinical testing, these results indicate that a sealant containing fluoride-releasing particles did not show a significant difference in retention rate compared to an unfilled conventional sealant. However, long-term results concerning marginal adaptation should be evaluated.

Caries prevalence in 11- to 14-year old migrant children in Germany

SummaryObjectives:To assess whether immigration stage is associated with higher prevalence of dental caries among schoolchildren in Heidelberg, Germany.Methods:A cross-sectional dental examination on 570 schoolchildren, aged 11 to 14 years, in schools with high proportions of immigrant pupils (49.5%) was performed. Carious, missing and filled permanent teeth were recorded for each child, so that mean DMFT values could be calculated. The pupils were classified into three groups: M0 (children and their parents were born in Germany), M1 (children who were born in Germany but whose parents were born outside of Germany), and M2 (children and their parents were born outside of Germany).Results:The mean DMFT values in M1 and M2 were close, and both were significantly higher than the corresponding values in M0. The proportions of caries-free children in M0, M1 and M2 were 63.7%, 40.3% and 42.3%, respectively.Conclusion:In Germany, migrant children have a poorer dental health status than native children coming from the same low socio-economic classes. Risk-oriented public health policies with appropriate prevention programs must be developed for these children.

Effect of cavity preparation instruments (oscillating or rotating) on the composite–dentin interface in primary teeth

OBJECTIVES To evaluate the effect of preparation of instruments on the interfacial integrity between cavity wall and composite restoration. METHODS Two class II slot preparations were done in 10 primary teeth either with SonicSys or with a conventional bur. The cavities were filled using an adhesive system. One layer of a flowable composite and one layer of a condensable composite were applied. The specimens were analyzed by confocal laser scanning microscopy. RESULTS In the SonicSys group the mean thickness of the hybrid layer was 6.12 (0.60) microm; in the control group it was 6.04 (0.63) microm. The difference was not statistically significant. Two fractures were observed in one tooth of each group. These were located only in the enamel. The cavity margins were beveled in all specimens. SIGNIFICANCE Compared to conventional preparations, cavity preparation with SonicSys has no deleterious effect on the integrity of the interface.

Formaldehyde Release from Ground Root Canal Sealer In Vitro

The formaldehyde release from three different ground root canal sealer materials was examined. Ten specimens each of AH26, Amubarut, and N2 were stored under dry conditions for 6 months. An amount of approximately 100 to 200 mg ground material was obtained from each sample by using a round bur and stored for 10 min in distilled water. The formaldehyde concentration of the immersion water was determined by high-performance liquid chromatography. The mean formaldehyde release per mg material was 6.6 (+/-2.5) microg for AH26 and 8.3 (+/-1.0) microg for Amubarut. A lower formaldehyde release was detectable by our method from the N2 samples (0.3 +/- 0.1 microg/g; p < 0.0001). In conclusion formaldehyde release from ground root canal material is low, although a risk of an allergic reaction in susceptible patients cannot be excluded.

The new selective IKs–blocking agent HMR 1556 restores sinus rhythm and prevents heart failure in pigs with persistent atrial fibrillation

AbstractBackgroundAntiarrhythmic drugs for treatment of atrial fibrillation in patients with heart failure are limited by proarrhythmia and low efficacy. Experimental studies indicate that the pure IKs blocking agents chromanol 293b and HMR 1556 prolong repolarization more markedly at fast than at slow heart rates and during β–adrenergic stimulation. These properties may overcome some of the above quoted limitations.Methods and resultsTen domestic swine underwent pacemaker implantation (PM) and atrial burst pacing to induce persistent AF. Four days after onset of persistent AF, pigs were randomized to HMR 1556 (30 mg/kg, p.o., 10 days) or placebo. All animals receiving HMR 1556 converted to SR (5.2 ± 1.9 days), whereas placebo pigs remained in AF. Pigs treated with placebo developed high ventricular rates (297 ± 5 bpm) and severe heart failure, whereas pigs treated with HMR 1556 remained hemodynamically stable. Left ventricular ejection fraction on the day of euthanization was significantly lower in the placebo compared to the HMR 1556 group (30 ± 4% vs. 69 ± 5%, p < 0.005). Similar results were seen with epinephrine levels (placebo 1563 ± 193 pmol/l vs. HMR 613 ± 196 pmol/l, p < 0.05). Right atrial monophasic action potentials were significantly longer in the HMR 1556 compared to the placebo group (230 ± 7 ms vs. 174 ± 13 ms, p < 0.05).ConclusionsThe new IKs blocker HMR 1556 efficiently and safely restores SR and prevents CHF in a model of persistent AF. Restoration of SR is most likely linked to a marked prolongation of atrial repolarization even at high heart rates.

Double-blind Study on Materials Testing with Applied Kinesiology

Applied Kinesiology (AK) is a scientifically unproven method used in complementary medicine to recognize the (in)tolerance of dental materials. Test-retest reliability of AK was examined. The working hypothesis was the assumption that the reliability of AK would not exceed random chance. Two dentists qualified in AK examined 112 volunteers to determine individual (in)tolerance toward two dental composite materials. After the first examination, 31 subjects were excluded from further testing. At the end of the open test phase, 34 of 81 participants had been classified as “tolerant”, and seven as “intolerant” to both materials. The remaining 40 individuals showed a combination of either tolerant (to material I)/intolerant (to material II), or the reverse (n = 20 each). Retrieval rate was tested under blind conditions. In 14 cases, the results of the open and blinded tests matched, whereas in 26 cases they did not (95% confidence interval, 21%-52%; p = 0.98). This outcome confirmed our working hypothesis.