Michaela Seydlova

Ceramic Bracket Debonding by Tm:YAP Laser Irradiation

OBJECTIVE The aim of this study was to prepare a simple and reliable method for ceramic bracket debonding, ensuring minimal changes in the enamel structure and an acceptable temperature rise in the pulp. BACKGROUND DATA Ceramic bracket debonding is based on the principle of degrading the strength of adhesive resin between the tooth and ceramic bracket. The search for a safe and efficient method of adhesive resin removal following debonding has resulted in the introduction of a wide range of instruments and procedures, among which proper use of laser irradiation can be promising. METHODS The debonding of two types of ceramic brackets utilized a diode-pumped Thulium:Ytterbium-Aluminium-Perovskite (Tm:YAP) microchip laser generating irradiation at a wavelength of 1998 nm (spot size 3 mm; focused by lens), with two power settings (1-2 W). Loss of enamel and residual resin on teeth, as well as rise in temperature inside the tooth were subsequently investigated in detail. RESULTS A 1W power of irradiation during a 60-sec period resulted in a temperature rise from 3 to 4°C in the approximate root location. This power is also suitable for debracketing from the point of view of damage to enamel lying below the bracket. Only a slight damage to the enamel was registered by SEM compared to conventional bracket removal. CONCLUSIONS Use of a Tm:YAP laser (wavelength 1998 nm, power 1 W, irradiance 14 W/cm(2), interacting time 60 sec) which is at the same time compact and small enough to be used in the dental practice, together with moderate cooling, could be an efficient tool for debracketing.

Electronic Health Record for Forensic Dentistry

OBJECTIVES To identify support of structured data entry for electronic health record application in forensic dentistry. METHODS The methods of structuring information in dentistry are described and validation of structured data entry in electronic health records for forensic dentistry is performed on several real cases with the interactive DentCross component. The connection of this component to MUDR and MUDRLite electronic health records is described. RESULTS The use of the electronic health record MUDRLite and the interactive DentCross component to collect dental information required by standardized Disaster Victim Identification Form by Interpol for possible victim identification is shown. CONCLUSIONS The analysis of structured data entry for dentistry using the DentCross component connected to an electronic health record showed the practical ability of the DentCross component to deliver a real service to dental care and the ability to support the identification of a person in forensic dentistry.

Voice-supported Electronic Health Record for Temporomandibular Joint Disorders

OBJECTIVES To identify support of structured data entry for an electronic health record application in temporomandibular joint disorders. METHODS The methods of structuring information in dentistry are described and the interactive DentCross component is introduced. A system of structured voice-supported data entry in electronic health record on several real cases in the field of dentistry is performed. The connection of this component to the MUDRLite electronic health record is described. RESULTS The use of DentVoice, an application which consists of the electronic health record MUDRLite and the voice-controlled interactive component DentCross, to collect dental information required by temporomandibular joint disorders is shown. CONCLUSIONS The DentVoice application with the DentCross component showed the practical ability of the temporomandibular joint disorder treatment support.

Dental implants and improvement of oral health-related quality of life

OBJECTIVES Oral health-related quality of life (OHRQoL) is a multifaceted field involving many factors. The aim of our study was to assess whether implant therapy improves OHRQoL in dental patients. METHODS Patients receiving at least one implant completed a health-related questionnaire before and after the implantation (minimum 1.5 months). Questions covered the functional and aesthetic scales (AS). Paired differences in individual scores were analysed using the Wilcoxon signed-rank test. A univariate analysis of covariance was used to relate overall and scale-specific average paired differences to age, gender, marital and educational status. Multivariate analysis of covariance was used to assess interactions between the covariates and different scales of outcome. All tests were performed at statistical significance level α = 0.05. RESULTS All twelve Wilcoxon tests supported an improvement in OHRQoL after implant placement. On the AS, the mean difference in OHRQoL scores was found to be associated with marital status, presence of aesthetic reasons for undergoing the surgery and number of front teeth replaced by implants. On the functional scale (FS), most significant associations were observed with the number of front teeth replaced via implantation, followed by the presence of chewing problems and marital status. The multivariate analysis helped to identify the covariates that varied significantly over the two scales of interest. CONCLUSIONS Effects of covariates responding significantly differently on different scales should not be summarized using an overall univariate analysis, using paired score differences averaged over all items. Such effect summary would be misleading. In the present study, significant implant-related improvements in OHRQoL were observed on both the aesthetic and FS in patients with at least one implant in the front dental area.

Biological properties of titanium implants covered with hydroxyapatite and zirconia layers by pulsed laser : In vitro study

The biological and physical properties of dental implants coated by the sandwich technique with a thin layer of hydroxyapatite and an interlayer of zirconia were evaluated. The implant samples were covered by pulsed laser deposition. The aim of our study is to evaluate the cytotoxicity and the surface characteristics of the titanium targets modified with zirconia and hydroxyapatite. The titanium substrates were analyzed physically by x-ray diffraction and scanning electron microscopy. We used a direct test of cytotoxicity to compare the prepared samples with other reference materials. No changes in the morphology or the proliferation rate of the cells used were found in the presence of the modified titanium targets. The adhesion, proliferation, and fibronectin expressions of human fibroblasts were also evaluated on the surface of the modified titanium targets. The results show that the modified titanium samples are at least as attractive as the tissue grade polystyrene in promoting fibroblasts’ adhesion a...

Biological and physical properties of pulsed-laser-deposited zirconia/hydroxyapatite on titanium : In vitro study

Coating dental implants with hydroxyapatite (HA) may give certain advantages such as active encouragement of new bone growth, a lower rejection rate, and an improved long-term prosthesis fixation. This study examined the mechanical and biological properties of titanium alloy implant cores with an interlayer of zirconia and a coating of HA created using pulsed Laser deposition (PLD). The thickness of the zirconia layer was 50–100 nm, and the HA layer was ∼600 nm. The crystallinity, morphology, wettability, and Ca/P ratio of the HA layer were investigated by electron microscopy, X-ray diffraction, goniometric measurement of contact angle, and wavelength dispersive X-ray analysis. The physical tests indicated adequate mechanical properties and a satisfactory adhesion to a titanium core modified with zirconia and HA. Cell proliferation and metabolic activity of human embryonal lung fibroblasts were determined using counting of harvested cells and providing an MTT assay. it was demonstrated that none of the samples were cytotoxic and their surfaces promoted cell colonization. PLD was found to be a promising method of applying coatings to a metal core for dental implants, and the in vitro biological tests suggest that the crystalline HA coating can improve the biological properties of titanium covered with zirconia.

Oral health-related quality of life and dental implants — preliminary study

Oral health-related quality of life (OHRQoL) is multifaceted and involves many factors. One of them is the use of dental implants. It was the aim of our study to assess whether implant therapy might improve OHRQoL. We consulted patients with at least one Astra Tech implant. Each patient completed oral health questionnaires, which were then statistically evaluated using the Wilcoxon signed-ranks test and Analysis of Covariance from a functional and aesthetic point of view. Differential response on individual scales was assessed using multivariate approach. All twelve marginal Wilcoxon tests showed an overall improvement in OHQoL (α = 0.05). On the aesthetic scale, OHRQoL was found to be associated with marital status, aesthetic reasons for undergoing surgery and number of front teeth replaced by implants. On the functional scale, three covariates were statistically significantly and appeared to have affected the levels of OHRQoL. The most significant explanatory effect was observed for the number of front teeth replaced via implantation, followed by the presence of chewing problems. Marital status was also found to have significantly affected the OHRQoL functional scale. Significant implant-related improvements in both scales were observed in patients with at least one implant in the front dental area.

Orthodontic patient - growth of somatic structures including implants insertion - 3D longitudinal reconstruction

Diagnostic orthodontic and prosthetic procedures commence with an initial examination, during which a number of individual findings on the occlusion or malocclusion are clarified. Geometrically calibrated images aid in the comparison of several different steps of the treatment and show a significant variation between patients before and after treatment. Geometric morphometrics represents a new approach in the evaluation of variability, and not only in medicine. The study presents methods which are based mainly on 3D co-ordinates of homologous landmarks that describe multidisciplinary therapy in dentistry.

Influence of crystallinity on bio- physical properties of hydroxyapatite films

Crystalline and amorphous hydroxyapatite (HA) films were prepared by KrF pulsed laser deposition method. Influence of HA structure on biomedical properties was studied. Crystallinity, morphology, composition, optical transmission and mechanical properties (adhesion) were measured. Biomedical properties were tested using human dermal fibroblast. The specific proteins (vimentin, fibronectin, pankeratin, keratin 14) were visualized. The worst proliferation of fibroblasts was observed on the amorphous coating, whereas the adhesion was well comparable with other surfaces. The level of keratinocyte differentiation on the amorphous and crystalline HA coating was the same. Results reached on physical and mechanical properties are discussed in connection with results of in vitro tests.

Hydroxyapatite and ZrO2 biocompatible coatings fabricated by pulsed laser deposition

Thin films of ZrO2 and hydroxyapatite/ZrO2 were created by pulsed laser deposition using KrF and ArF excimer laser. Films were tested by XRD, SEM and WDX methods and in-vitro for cytotoxicity, adhesion and cell proliferation.