Publications by authors named "Andreas Hellak"
Purpose: The aim of this study was to assess the effects of tooth/bone-borne (hybrid) and tooth-borne (TB) surgically assisted rapid maxillary expansion (SARME) on the width of the nasal soft and hard tissue.
Patients And Methods: Twenty skeletally mature patients (nine males and 11 females; mean age 19.4 years) with transverse maxillary hypoplasia were randomly assigned to hybrid or TB devices.
Background: The aim of this study was to use three-dimensional datasets to identify associations between treatment for adult crowding, using Invisalign aligner and interproximal enamel reduction (IER), and changes in the volume of interradicular bone.
Methods: A total of 60 cone-beam computed tomography (CBCT) scans from 30 adult patients (28 women, two men; 30 CBCTs pre-treatment, 30 post-treatment) were examined retrospectively in order to measure bone volume three-dimensionally. The patients' average age was 36.
Objective: The objective of this split-mouth trial was to investigate the influence of photobiomodulation therapy (PBMT) on adjuvant treatment of gingivitis induced by multi-bracket appliances, after bracket debonding and professional tooth cleaning.
Materials And Methods: Thirteen patients (mean age 16.15 years; standard deviation ±2.
Objective: This study investigated temperature increases in dental pulp resulting from laser-assisted debonding of ceramic brackets using a 445-nm diode laser.
Materials And Methods: Eighteen ceramic brackets were bonded in standardized manner to 18 caries-free human third molars. Pulpal fluid circulation was simulated by pumping distilled water at 37°C through the pulp chamber.
Objective: The aim of this study was to measure the effect of irradiation with a novel 445-nm diode laser on the shear bond strength (SBS) of ceramic brackets before debonding.
Materials And Methods: Thirty ceramic brackets (In-Ovation C, GAC) were bonded in standard manner to the planed and polished buccal enamel surfaces of 30 caries-free human third molars. Each tooth was randomly allocated to the laser or control group, with 15 samples per group.
Objectives: This study determined the influence of irradiation on aesthetic ceramic brackets with a novel 445-nm diode laser prior to debonding on the bracket failure mode.
Materials And Methods: Thirty ceramic brackets (In-Ovation® C, GAC) were standard-bonded to the oral and buccal planed and polished enamel surfaces of 15 caries-free human 3rd molars. Prior to study-blinded debonding, the brackets in the laser group were irradiated with the diode laser (SIROLaser Blue®, Sirona), while the irradiation was simulated within the conventional group.
Aim: The aim of this study was to investigate possible correlation of specific skeletal or dental class in children and adolescents with clinical signs of temporomandibular dysfunction (TMD) with the severity of internal derangement (ID) of the temporomandibular joint.
Materials And Methods: Based on MRI images, the ID of 232 juvenile temporomandibular joints in 116 patients were retrospectively recorded. The distribution of the ID stages within the skeletal and dental classes was compared by means of the χ test.
The aim of this in vitro study was to determine the shear bond strength (SBS) and adhesive remnant index (ARI) score of two self-etching no-mix adhesives (iBond and Scotchbond) on different prosthetic surfaces and enamel, in comparison with the commonly used total etch system Transbond XT. . A total of 270 surfaces (1 enamel and 8 restorative surfaces, = 30) were randomly divided into three adhesive groups.
View Article and Find Full Text PDFBackground: The aim of this study was to use three-dimensional datasets to identify associations between treatment for adult crowding using Invisalign and interproximal enamel reduction (IER) and changes in the bone volume.
Methods: A total of 60 digital cone beam computed tomography (CBCT) scans from 30 patients (28 women, two men; 30 CBCTs pretreatment, 30 posttreatment) were examined retrospectively in order to record bone volume three-dimensionally before and after treatment. The patients' average age was 36.
Objective: The aim of this in vitro study was to compare the shear bond strength (SBS) and Adhesive Remnant Index (ARI) scores of two self-etching no-mix adhesives (Prompt L-Pop™ and Scotchbond™) for orthodontic appliances to the commonly used total etch system Transbond XT™ (in combination with phosphoric acid).
Materials And Methods: In all, 60 human premolars were randomly divided into three groups of 20 specimens each. In group 1 (control), brackets were bonded with Transbond™ XT primer.
Background: To determine the shear bond strength and adhesive remnant index of a new premixed self-etching primer and adhesive (Tectosan, BonaDent, Germany) for orthodontic appliances in comparison to a reference total-etch system Transbond XT.
Methods: Bovine incisors were embedded in resin and randomly divided into two groups of 16 samples each. Brackets (Discovery, Dentaurum, Germany) were bonded in group 1 (total-etch-system, Transbond XT) and in group 2 (self-etch-system, Tectosan) with curing light for 40 s.
Objectives: Surgical correction of skeletal maxillary retroposition is often associated with changes in the morphology of the nose. Unwanted alar flaring of the nose is observed in many cases. The aim of the present study was therefore to investigate the influence of surgical advancement of the maxilla on changes in the soft-tissue morphology of the nose.
View Article and Find Full Text PDFBackground: The objective of this study was to determine whether the addition of microsilver or nanosilver particles to an orthodontic primer affects shear bond strength (SBS) and bracket/adhesive failure.
Methods: Bovine incisors were randomly divided into six groups with 16 specimens in each: In group 1 (control), brackets were bonded with Transbond™ XT primer. In the experimental groups, microsilver (groups 2 and 3) and nanosilver (groups 4-6) particles of different sizes were added to Transbond XT primer and light cured for 15 seconds [group 2: 0.
Objectives: The aim of this in vitro study was to investigate the demineralization rate in human enamel after interproximal polishing (IPP) and to detect possible correlations with the IPP method used, with special emphasis on the surface characteristics of the enamel being treated.
Materials And Methods: This in vitro study tested five IPP systems (Profin Directional System®, Intensiv ProxoStrip®, OS discs®, ARS Safe-Tipped Bur Kit® and Ortho-Strips Set®) that are currently available on the market. Each of the five examination groups comprised 12 randomly selected teeth, while the control group consisted of six teeth.
Introduction: Rapid maxillary expansion (RME) is a common technique to improve the dental and skeletal transverse width in cases of constricted maxillary arches. Although retention after RME has been widely examined, there is still no clear statement about the minimal retention time in postpubertal patients and many practitioners have retention concepts varying between three and six months.
Methods: This retrospective study consisted of 14 patients who were either treated with a Haas-type RME (6 patients) or a Hybrid-RME (8 patients).
Objective: To assess the surface roughness resulting after application of currently available interproximal polishing.
Materials And Methods: The analysis was carried out by means of digital subtraction radiography, profilometry, and scanning electron microscopy. The roughness of natural untreated enamel served as the reference.