Angelika Callaway

In vitro analysis of the cytotoxicity and the antimicrobial effect of four endodontic sealers

IntroductionThe aim of this study was to investigate in vitro the cytotoxicity and antibacterial properties of four different endodontic sealers using human periodontal ligament fibroblast cell proliferation and visual analysis of growth inhibition.MethodsA silicone (GuttaFlow), silicate (EndoSequence BC), zinc oxide eugenol (Pulp Canal Sealer EWT) and epoxy resin (AH Plus Jet) based sealer were incubated with PDL fibroblasts (104 cells/ml, n = 6) up to 96 h. Cell proliferation (RFU) was determined by means of the Alamar Blue assay. Cell growth and morphology was visualized by means of fluorescent dyes. Possible antibacterial properties of the different sealers were visualized by means of SEM (Enterococcus faecalis; Parvimonas micra).ResultsFibroblast proliferation depended on sealer and cultivation time. After 72 and 96 h GuttaFlow and EndoSequence BC showed relatively non-cytotoxic reactions, while Pulp Canal Sealer EWT and AH Plus Jet caused a significant decrease of cell proliferation (p < 0.001). Visualization of cell growth and morphology with various fluorescent dyes supplemented the results. No antibacterial effect of EndoSequence BC to P. micra was found, whereas GuttaFlow showed a weak, Pulp Canal Sealer EWT and AH Plus Jet extensive growth inhibition. Also, no antibacterial effect of GuttaFlow, EndoSequence BC or AH Plus Jet to E. faecalis could be detected.ConclusionsThese in vitro findings reveal that GuttaFlow and EndoSequence BC can be considered as biocompatible sealing materials. However, prior to their clinical employment, studies regarding their sealing properties also need to be considered.

Comparison between scaling-root-planing (SRP) and SRP/photodynamic therapy: six-month study

IntroductionThe purpose of this long-term clinical study was to examine the additional efficacy of photodynamic therapy (PDT) to scaling and root planing (SRP) in patients with chronic periodontal disease.MethodsA total of 22 patients (mean age: 59.3 ± 11.7 years) with chronic periodontal disease and four teeth with probing depth ≥ 5 mm were enrolled in the study. Inclusion criteria were: no systemic disease, no smoking, no pregnancy and no long-term medication. Beside the anamnesis, the following clinical parameters were assessed at baseline (one week before therapy), and one, three and six months after the therapy: bleeding on probing (BOP), plaque index (PI) probing depth (PD), and clinical attachment loss. All measurements were done by the same examiner with a fixed periodontal probe (PCP 12, Hu-Friedy) at six measurements/tooth. In each patient, two teeth were treated with SRP alone and two teeth with SRP and PDT (Periowave, Ondine Biopharma, Vancouver, Canada). The nonparametric Wilcoxon test for paired samples was used for comparison of the effect of the two treatments (p ≤ 0.05).ResultsAfter both types of treatment, the number of teeth positive for BOP declined. At baseline, the CAL measured 7.2 ± 1.2 mm (SRP) or 8.1 ± 1.3 mm (SRP/PDT); one, three and six months after both types of treatment an improvement was observed. At baseline, the probing depth was 5.9 ± 0.8 mm (SRP) or 6.4 ± 0.8 mm (SRP/PDT); after six months, an improvement of 2.4 ± 0.6 mm (SRP) or 2.9 ± 0.8 mm (SRP/PDT) was found. The greater reduction of the PD, achieved by a combination of SRP/PDT, was statistically significant after six months (p = 0.007).ConclusionThis clinical study demonstrates that SRP in combination with PDT seems to be effective and is therefore suitable as an adjuvant therapy to the mechanical conditioning of the periodontal pockets in patients with chronic periodontal diseases.

Influence of Bleaching Agents on Surface Roughness of Sound or Eroded Dental Enamel Specimens

PURPOSE The aim of the present in vitro study was to assess the effect of bleaching agents on eroded and sound enamel specimens. MATERIALS AND METHODS Enamel specimens prepared from human permanent anterior teeth were incubated with different bleaching agents containing active ingredients as 7.5 or 13.5% hydrogen peroxide or 35% carbamide peroxide, ranging in pH from 4.9 to 10.8. The effect of the tooth whitening agents on surface roughness was tested for sound enamel surfaces as well as for eroded enamel specimens. To provoke erosive damage, the enamel specimens were incubated for 10 hours with apple juice (pH = 3.4). Afterwards, pretreated and untreated dental slices were incubated with one of the bleaching agents for 10 hours. The surface roughness (R(a)) of all enamel specimens (N = 80) was measured using an optical profilometric device. A descriptive statistical analysis of the R(a) values was performed. RESULTS The study demonstrated that exposure to an acidic bleaching agent (pH = 4.9) resulted in a higher surface roughness (p = 0.043) than treatment with a high peroxide concentration (pH = 6.15). If the enamel surface was previously exposed to erosive beverages, subsequent bleaching may enhance damage to the dental hard tissue. CONCLUSION Bleaching agents with a high concentration of peroxide or an acidic pH can influence the surface roughness of sound or eroded enamel.

Diversity of Lactobacillus species in deep carious lesions of primary molars

AIM: This was to determine the prevalence of Lactobacilli (LB) species in different stages of caries progression and are considered as secondary invaders of existing carious lesions and specialists for caries progression. METHODS: Carious dentine samples were collected from 70 primary molars (M) during step-wise (S1, S2: n = 35 M) or one-step (O1: n = 35 M) caries treatment and after 11 months of temporary restorations (S3, O2). LB were identified by selected physiological and biochemical characteristics, ratio of lactic acid isomers, electrophoretic mobilities of lactic acid dehydrogenases, and shotgun mass mapping by MALDI mass spectrometry. RESULTS: LB were isolated from 46% of soft dentine samples (S1). The prevalence of LB from hard dentine collected during caries excavation (O1) reached 34%, after 8 weeks of temporary filling (S2) 11%, and 9% each after 11 months of temporary restoration (S3, O2). The mean total bacterial counts (cfu) of soft dentine (S1) were 3.6 × 105. From hard dentine during caries excavation (O1 ) 4.4×104 cfu were calculated, at S2 3.7 × 103 cfu, at S3 0.1 × 103 cfu, and at O2 1.8 × 103 cfu. The percentages of LB in the cfu for LB positive dentine samples were for S1 / S2 / S3 / O1 / O2: 60% (16 M)/34% (4 M)/54% (3 M)/57% (9 M), and 64% (3 M). Five LB species were identified from carious dentine: L. paracasei subsp. paracasei, L. paracasei subsp. tolerans, L. rhamnosus, L. gasseri, and L. alimentarius. CONCLUSIONS: While L. rhamnosus and L. paracasei subsp. paracasei occurred in all caries progression stages, the other species were found only sporadically. L. paracasei subsp. paracasei and L. rhamnosus might be the specialists of the LB in carious progression.

Prolonged in vitro exposure to white wines enhances the erosive damage on human permanent teeth compared with red wines

The aim of this in vitro study was to determine and compare the erosive potentials of red and white wines, exerted on enamel surfaces prepared from extracted human permanent teeth. European wines (50 red, 50 white wines) from different regions were purchased, and the pH values were measured. Eight wines with different pH values were selected. Enamel samples with an average surface area of 25 mm(2) were prepared from 25 extracted permanent teeth from male and female patients aged 40 to 65 years and incubated with wines for up to 24 hours; the amounts of released calcium were determined colorimetrically, and mean surface roughness was measured with a profilometer. A quantitative elemental analysis for Ca was carried out in various depths (5-50 microm), using an electron probe microanalyzer. Incubation of the enamel surfaces with different wines caused a time-dependent release of calcium. After 24 hours, white wines caused a significantly higher (P = .003) Ca release (range: 8.74-28.56 mg dL(-1) 25 mm(-2)) than red wines (range: 4.85-19.43 mg dL(-1) 25 mm(-2)), whereas the values for surface roughness were similar (white wines: 2.67 +/- 0.92 microm; red wines: 2.64 +/- 0.66 mum). Incubation with white wines resulted in a higher loss of Ca down to a depth of 60 microm. In this study, it was demonstrated that white wines have higher erosive potentials than red wines. Within the limits of this in vitro study, it can be predicted that a frequent consumption of white wines might lead to severe dental erosion.

Dental age assessment in 6- to 14-year old German children: comparison of Cameriere and Demirjian methods

BackgroundThe aim of the study was to compare two frequently used dental age estimation methods for accuracy.MethodsA total of 479 panoramic radiographs in age groups 6–14 years from a German population were evaluated. The dental age of 268 boys and 211 girls was assessed by means of the method of Demirjian (1973) and Cameriere (2006) and compared with their actual chronological age.ResultsDemirjan’s method showed an overestimation of dental age compared to chronological age in all age groups for boys (mean difference −0.16, p = 0.010, range −0.35 to 0.09), age group 9 showed an underestimation. Using the same method for girls (mean difference −0.18, p = 0.008, range −0.45 to 0.13), an overestimation could also be shown in all age groups except for age groups 8 and 13. Results for Cameriere’s method showed for boys (mean difference 0.07, p = 0.314, range −1.38 to 3.83) in age groups 6 to 11 an overestimation, but in age groups 12 to14 an underestimation. The results for girls (mean difference 0.08, p = 0.480, range −1.55 to 4.51) showed an overestimation for age groups from 6 to 10, and an underestimation in age groups 11 to 14.ConclusionsThe comparison shows an advantage of Demirjian’s method for both genders. While Cameriere’s method showed a higher inaccuracy in all age groups, Demirjian’s method showed more appropriate results for dental age estimation of the investigated German population. To avoid errors in forensic age estimation and to prevent misidentifications for defendants in criminal processes, further studies of more precise methods for age estimation for the German population are required.

Hypnosis and Local Anesthesia for Dental Pain Relief-Alternative or Adjunct Therapy?-A Randomized, Clinical-Experimental Crossover Study.

Abstract This prospective randomized clinical crossover trial was designed to compare hypnosis and local anesthesia for experimental dental pain relief. Pain thresholds of the dental pulp were determined. A targeted standardized pain stimulus was applied and rated on the Visual Analogue Scale (0–10). The pain threshold was lower under hypnosis (58.3 ± 17.3, p < .001), maximal (80.0) under local anesthesia. The pain stimulus was scored higher under hypnosis (3.9 ± 3.8) than with local anesthesia (0.0, p < .001). Local anesthesia was superior to hypnosis and is a safe and effective method for pain relief in dentistry. Hypnosis seems to produce similar effects observed under sedation. It can be used in addition to local anesthesia and in individual cases as an alternative for pain control in dentistry.

Influence of different biomaterials on the viability of Aggregatibacter actinomycetemcomitans

OBJECTIVES The aim of the present in vitro study was to evaluate the effects of different biomaterials used for regenerative periodontal surgery on the growth of the periodontopathogen Aggregatibacter actinomycetemcomitans. METHODS Three commercially available biomaterials of synthetic origin (hydroxyapatite/beta-tricalcium phosphate, nanostructured hydroxyapatite paste, oily calcium hydroxide suspension), a bovine-derived xenograft as well as an enamel matrix derivative (EMD) were added in different concentrations to calibrated suspensions of A. actinomycetemcomitans ATCC 43718/33384 (serotype b/c). Equal aliquots (0.1 ml) for the viability assay were taken after 5 min, 1h, 3h, 8h and 24h, plated on blood agar and incubated in an anaerobic environment for 48 h at 37°C. Viable cell counts were expressed as colony forming units (cfu)/0.1 ml. RESULTS The results demonstrated that none of the investigated biomaterials could inhibit the growth of A. actinomycetemcomitans serotype b. A marked growth reduction of A. actinomycetemcomitans serotype c was observed in the presence of oily calcium hydroxide suspension and nanostructured hydroxyapatite. In contrast, no significant growth inhibition could be observed in the presence of hydroxyapatite/beta-tricalcium phosphate, enamel matrix derivative and bovine-derived xenograft. CONCLUSIONS The results of the present study suggest that none of the investigated biomaterials possesses antimicrobial properties against A. actinomycetemcomitans serotype b. Therefore, the use of these biomaterials for regenerative procedures should be weighted critically in the presence of A. actinomycetemcomitans serotype b.