Gholamreza Danesh

Publications of Gholamreza Danesh

• Elution characteristics of residual monomers in different light- and auto-curing resins.

  Authors: Gholamreza Danesh, Tobias Hellak, Klaus-Jürgen Reinhardt, András Végh, Edgar Schäfer, Carsten Lippold

  Experimental and toxicologic pathology : official journal of the Gesellschaft fur Toxikologische Pathologie. 04/2011;

  The aim of this in vitro study was to assess different auto-curing resins based on methylmethacrylate (MMA) and new light-curing resins based on urethane dimethacrylate (UDMA) regarding the residualThe aim of this in vitro study was to assess different auto-curing resins based on methylmethacrylate (MMA) and new light-curing resins based on urethane dimethacrylate (UDMA) regarding the residual monomers remaining in the resin and their elution over time. Specimens from three auto-curing and three light-curing resins were produced following the manufacturer's instructions. The concentration of residual MMA and UDMA monomers present in the resins as well as the quantity of the residual monomers released into artificial saliva solution after immersion times of 1, 3, and 7 days were analyzed by high-performance liquid chromatography (HPLC). Data were statistically analyzed using ANOVA and the post hoc Student-Newman-Keuls test. The highest and lowest amounts of residual monomers were found in the group of light-curing resins (p<0.05). The light-curing resins Triad Trans Sheet (0.06wt%) and Primosplint (0.06wt%) released over the entire immersion time of 7 days the smallest (p<0.05) quantity of UDMA. These two light-curing resins based on UDMA exhibited lower elution of residual monomers than auto-curing resins (MMA). The elution characteristics of the residual monomers do not seem to correlate with the residual monomer concentration in resins. These observations demonstrate that the quantitative determination of residual monomers alone - as required by the ISO specification 20795-1 - does not seem to be sufficient for an assessment of the biological properties of different resins. Instead, the evaluation of elution characteristics appears to be of higher clinical relevance.

• Sagittal back contour and craniofacial morphology in preadolescents.

  Authors: Carsten Lippold, Emil Segatto, András Végh, Burkhard Drerup, Tatjana Moiseenko, Gholamreza Danesh

  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 11/2009;

  The aim of this study was to analyze the correlation ratios between the sagittal back contour (flèche cervicale and lombaire, trunk inclination) and selected parameters of craniofacial morphology inThe aim of this study was to analyze the correlation ratios between the sagittal back contour (flèche cervicale and lombaire, trunk inclination) and selected parameters of craniofacial morphology in children. The patient sample consisted of 66 healthy children with a mean age of 11.2 years (SD 1.6 years), of which 34 were male (mean age 11.5 years, SD 1.3 years) and 32 were females (mean age 10.9 years, SD 1.9 years). The children were recruited during the preparation of the initial orthodontic treatment records. Craniofacial morphology was analyzed by six angular measurements: facial axis, mandibular plane angle, inner gonial angle, lower facial height, facial depth and maxilla position. Rasterstereography was used for reconstruction of the spinal back sagittal profile. From the profile flèche cervicale, flèche lombaire and trunk inclination were determined and the correlations with the craniofacial morphology were calculated (Pearson and Mann-Whitney U test). Significant correlations were found with respect to the inner gonial angle and the flèche cervicale, the mandibular plane angle and the flèche lombaire, the inner gonial angle and the flèche lombaire, and the angular lower facial height and the flèche lombaire, as well as the inner gonial angle and the trunk inclination. The craniofacial vertical growth pattern, presented by mandibular plane angle, inner gonial angle and the angular lower facial height, and the correlation to flèche cervicale and lombaire as well as trunk inclination reveal correlations between growth pattern and sagittal back contour.

• Analysis of condylar differences in functional unilateral posterior crossbite during early treatment--a randomized clinical study.

  Authors: Carsten Lippold, Gloria Hoppe, Tatjana Moiseenko, Ulrike Ehmer, Gholamreza Danesh

  Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie. 08/2008; 69(4):283-96.

  OBJECTIVE: The analysis of potential discrepancies in condyle position among different occlusal relations (centric relation and maximum intercuspidation) is a key diagnostic component when treatingOBJECTIVE: The analysis of potential discrepancies in condyle position among different occlusal relations (centric relation and maximum intercuspidation) is a key diagnostic component when treating children with unilateral posterior crossbite. Due to strict requirements imposed by ethics committees, and new regulations regarding the use of X-rays, radiological examinations (axial cephalometric radiographs or postero-anterior cephalometric radiographs) are not feasible. Thus the aim of this study was to apply an alternative procedure for the assessment of condylar deviations. PROBANDS AND METHODS: : We employed ARCUS digma, a measuring system based on ultrasound technology, to record condylar differences occurring in 65 children (6.9+/-2.0 years of age) with functional unilateral posterior crossbite in late deciduous and early mixed dentition. After randomization, 31 patients underwent early orthodontic treatment (bonded palatal expansion appliance and U-bow activator), whereas 34 patients remained untreated. Examinations were carried out at the beginning (T1) and after 12 months of treatment (T2). A three-dimensional (3D) assessment of deviations between maximum intercuspidation and centric position was carried out. Statistical analysis was performed using the SPSS 12.0 software program. RESULTS: Initially, the electronic position analysis revealed no significant differences between the control and therapy groups. A mean condylar deviation of > 2 mm was noted at T1 in the sagittal, frontal and transversal planes for crossbite and the noncrossbite sides. This difference was reduced in the therapy group, a finding that proved statistically highly significant (p<0.001). We also observed a highly significant (p<0.001) difference between the control and therapy groups at T2. CONCLUSION: The Münster concept for early treatment of functional unilateral posterior crossbites in late deciduous and early mixed dentition significantly improved the treated patients' occlusion in comparison to a randomized control group, which exhibited no spontaneous self-healing tendencies.

• Enamel surfaces following interproximal reduction with different methods.

  Authors: Gholamreza Danesh, Andreas Hellak, Carsten Lippold, Thomas Ziebura, Edgar Schafer

  The Angle orthodontist. 11/2007; 77(6):1004-10.

  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 digitalOBJECTIVE: 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. Five enamel reduction methods were tested (Profin, New Metal Strips, O-Drive D30, Air Rotor, and the Ortho-Strips) and were applied in accordance with their manufacturers' recommendations. Fifty-five teeth were treated by randomly chosen methods, all of which were applied by one person. One proximal surface was only ground and left unpolished while the other received the finishing and polish recommended by the manufacturer. RESULTS: Loss of tooth substance, as measured by subtraction radiography, was significantly lower (P < .05) for the group treated with Ortho-Strips. Profilometric analysis of enamel roughness showed that the use of Ortho-Strips, O-Drive D30, and New Metal Strips in the grinding mode produced equally rough surfaces (P > .05). The Air Rotor and Profin system in the grinding mode produced the significantly (P < .05) roughest surfaces. A significant (P < .05) reduction of the mean roughness values was registered in all groups when treatment was followed by polishing. The Profin system and Ortho-Strips achieved the significantly smoothest surfaces (P < .05) with polishing. CONCLUSIONS: In general, interproximal enamel reduction should be followed by thorough polishing. Furthermore, oscillating systems seem to be advantageous.

• Treatment of hemimandibular hyperplasia: the biological basis of condylectomy.

  Authors: Carsten Lippold, Birgit Kruse-Losler, Gholamreza Danesh, Ulrich Joos, Ulrich Meyer

  The British journal of oral & maxillofacial surgery. 08/2007; 45(5):353-60.

  Treatments to correct skeletal deformities in patients with hemimandibular hyperplasia differ, particularly about the age at which the operation is done and the operation itself. To some extent, theTreatments to correct skeletal deformities in patients with hemimandibular hyperplasia differ, particularly about the age at which the operation is done and the operation itself. To some extent, the differences can be attributed to the unknown biological basis of disease. The aim of the present study was to evaluate clinically the outcome of a rationale for the operation based on condylectomy on the affected side. Histological, radiological, and nuclear methods were used to get a more detailed insight into the reason for the operation. Six patients with hemimandibular hyperplasia were treated by a combined orthodontic-maxillofacial protocol. All patients had the affected joint removed. The histological morphology of each condylar specimen was compared with the bone scintigraphy to try and find a correlation between the methods. The clinical evaluation showed morphological and functional rehabilitation of all six patients. During the 2-year follow-up, all patients had stable symmetrical mandibles with no disturbance of temporomandibular function. Remodelling of the joint and the destruction of the cartilaginous layer was accompanied by much bone scintigraphic activity. We conclude that condylectomy can correct hemimandibular hyperplasia, even in patients with active condylar growth, by removing the underlying disease.

• Trunk inclination, pelvic tilt and pelvic rotation in relation to the craniofacial morphology in adults.

  Authors: Carsten Lippold, Gholamreza Danesh, Gloria Hoppe, Burkhard Drerup, Lars Hackenberg

  The Angle orthodontist. 02/2007; 77(1):29-35.

  OBJECTIVE: To relate the differences in the posture of patients with different craniofacial morphologies. SUBJECTS AND METHODS: Fifty-three adult patients with Class II and III malformations wereOBJECTIVE: To relate the differences in the posture of patients with different craniofacial morphologies. SUBJECTS AND METHODS: Fifty-three adult patients with Class II and III malformations were examined by cephalometric analysis and rasterstereography. The facial depth, maxillary position, mandibular plane angle, inner gonial angle, facial axis, and lower facial height were evaluated and classified into a basal distal-mesial group and a horizontal-vertical group by means of threshold parameters. Analyzing the results of the rasterstereography, the spine's lateral perpendicular deviation, the pelvic tilt, and the pelvic rotation were calculated by means of mathematical algorithms on the basis of the three-dimensional spine profile. To determine the statistically significant correlations between the studied parameters, the t-test was applied in groups with a normal distribution, and the Mann-Whitney U-test was used in the cases of abnormally distributed variables (significance level P < .05). RESULTS: Statistically significant differences (P < .05) in pelvic torsion were documented with respect to the facial axis and facial depth. Moreover, the differences (P < .05) between patients with a skeletal horizontal-vertical facial axis and patients with a basal distal-mesial position for the facial depth could be determined for the pelvic torsion. CONCLUSIONS: As a clinical consequence of the results, an extension of the interdisciplinary concepts within the sense of an orthopedic examination can be considered for patients undergoing a combined orthodontic-operative therapy.

• A fused maxillary central incisor with dens evaginatus as a talon cusp.

  Authors: Gholamreza Danesh, Tine Schrijnemakers, Carsten Lippold, Edgar Schäfer

  The Angle orthodontist. 02/2007; 77(1):176-80.

  This report presents a rare case of concurrence of dens evaginatus and dental fusion affecting the maxillary right upper central incisor of a 9-year-old male patient. An association of densThis report presents a rare case of concurrence of dens evaginatus and dental fusion affecting the maxillary right upper central incisor of a 9-year-old male patient. An association of dens evaginatus and dental fusion within the same tooth is rare. In this case, an orthopantomogram, a lateral cephalogram, intraoral radiographs, and a magnetic resonance tomogram were made to obtain a proper diagnosis and to confirm the exact path of the root canals. Because of a forced bite, an orthodontic treatment involving cusp reduction was initiated. During the cusp reduction, no traumatic intraoperative exposure of pulp tissue occurred, and no endodontic or surgical treatment procedures were necessary. After a multibracket treatment, a harmonious integration of the tooth in the upper dental arch was achieved.

• Relationship between thoracic, lordotic, and pelvic inclination and craniofacial morphology in adults.

  Authors: Carsten Lippold, Gholamreza Danesh, Markus Schilgen, Burkhard Drerup, Lars Hackenberg

  The Angle orthodontist. 10/2006; 76(5):779-85.

  OBJECTIVE: To analyze the correlation ratios between the spinal posture (thoracic, lordotic, and pelvic inclination) and the craniofacial morphology. MATERIALS AND METHODS: The sample consisted of 53OBJECTIVE: To analyze the correlation ratios between the spinal posture (thoracic, lordotic, and pelvic inclination) and the craniofacial morphology. MATERIALS AND METHODS: The sample consisted of 53 healthy adults (32 women, 21 men; mean age 24.6 years). Six angular skeletal measurements (facial axis, mandibular plane angle, inner gonial angle, lower facial height, facial depth, and maxilla position) were determined based on the analysis of lateral head cephalographs. Rasterstereography was used for a precise reconstruction of the back sagittal profile. From the profile parameters, the upper thoracic inclination, the thoracic angle, the lordotic angle, and the pelvic inclination were determined. The correlations to the craniofacial morphology were calculated by means of the Pearson and Mann-Whitney U-test. RESULTS: Significant correlations could be obtained with respect to the facial axis and the lordotic angle, the facial axis and the pelvic inclination, the inner gonial angle and the lordotic angle, the inner gonial angle and the pelvic inclination, the mandibular plane angle and the lordotic angle, the mandibular plane angle and the pelvic inclination, as well as the facial depth and the pelvic inclination. CONCLUSIONS: In the case of postural disorders of the back shape, an interdisciplinary treatment approach seems to be of clinical value. Further prospective studies are necessary to prove how changes in craniofacial parameters can affect the postural balance of an individual.

• Sagittal spinal posture in relation to craniofacial morphology.

  Authors: Carsten Lippold, Gholamreza Danesh, Gloria Hoppe, Burkhard Drerup, Lars Hackenberg

  The Angle orthodontist. 08/2006; 76(4):625-31.

  OBJECTIVE: The aim of this study is to determine correlations between the parameters of body posture in the sagittal profile and sagittal jaw position by obtaining objective and validOBJECTIVE: The aim of this study is to determine correlations between the parameters of body posture in the sagittal profile and sagittal jaw position by obtaining objective and valid three-dimensional measurements of the dorsal profile by means of rasterstereography. MATERIALS AND METHODS: Fifty-three adults with Class II or III malocclusions were examined, and six angular parameters were determined. For the sagittal analysis of body posture, the Fleche Cervicale and Lombaire as well as trunk inclination were evaluated. RESULTS: Statistically significant correlations (P < .05) were found between Facial Axis and Fleche Cervicale, Mandibular Plane angle and Fleche Cervicale, and Facial Depth and the Fleche Cervicale. CONCLUSIONS: It can be concluded that the mandible seems to have a greater effect on body posture than other craniofacial parameters. As a clinical result of this study, patients with severe malocclusions should be examined interdisciplinarily before orthognathic surgery is performed to minimize postural influence on the altered jaw relationship after surgery.

• Polymerization characteristics of light- and auto-curing resins for individual splints.

  Authors: Gholamreza Danesh, Carsten Lippold, Karl-Ludwig Mischke, Babak Varzideh, Klaus-Jürgen Reinhardt, Till Dammaschke, Edgar Schäfer

  Dental materials : official publication of the Academy of Dental Materials. 05/2006; 22(5):426-33.

  OBJECTIVES: The aim of this in vitro study was to assess different resins for occlusal splints regarding a number of polymerization characteristics. METHODS: One autopolymerizing resin (Palapress)OBJECTIVES: The aim of this in vitro study was to assess different resins for occlusal splints regarding a number of polymerization characteristics. METHODS: One autopolymerizing resin (Palapress) and four light-curing resins (Acrylight, Primosplint, Triad TranSheet Colorless and Pink) were tested for flexural strength, modulus of elasticity, water sorption, volumetric shrinkage, and conversion of double bonds. These resins were polymerized for 10 and 15 min in a light oven at frequencies between 320 and 400 nm or 400 and 500 nm, respectively. Data were treated statistically by ANOVA and by Scheffé test. RESULTS: Concerning flexural strength and modulus of elasticity, Triad TranSheet Colorless showed significantly greater values than Primosplint and Palapress (p<0.05). The light curing resins Acrylight and Primosplint featured significantly higher water sorption when cured for 10 min compared to all other resins (p<0.05). Acrylight displayed significantly higher volumetric shrinkage and a higher quantity of remaining double bonds compared to all other light-curing resins (p<0.05). Primosplint, Triad TranSheet Colorless and Pink showed significantly lower shrinkage values than autopolymerizing Palapress (p<0.05). For all light curing resins, polishing of the samples resulted in a significantly lower quantity of remaining double bonds (p<0.05) compared to unpolished samples. SIGNIFICANCE: With respect to the polymerization properties evaluated, the light-curing resins reached similar material properties to the autopolymerizing resin or even surpassed them. Light-curing resins seem to be suitable for the fabrication of occlusal splints and can been seen as an alternative to autopolymerizing polymethylmethacrylates.

• In-vitro investigations on suitability of light-cured resins for interocclusal splints: part I: mechanical properties.

  Authors: Gholamreza Danesh, Carsten Lippold, Thomas Ziebura, Klaus-Jürgen Reinhardt, Edgar Schäfer, Ulrike Ehmer

  Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie. 03/2006; 67(2):127-37.

  OBJECTIVE: It was the aim of the present study to investigate the material properties of different resins and their suitability for the fabrication of occlusal and intermaxillary splints. MATERIALOBJECTIVE: It was the aim of the present study to investigate the material properties of different resins and their suitability for the fabrication of occlusal and intermaxillary splints. MATERIAL AND METHOD: We subjected auto-polymerized resins (Palapress, Orthocryl, Steady-Resin M) and light-polymerized resins (Acrylight, Primosplint, Triad TranSheet Colorless and Pink) to investigation. The Targis Power light oven was used to polymerize the light-cured resins. After the auto-polymerized resins had been mixed by hand and filled into the forms, they were polymerized for 15 minutes in a high-pressure polymerization machine (Palamat) at 2 bar. The parameters examined were flexural strength, water adsorption, and polymerization shrinkage. Tests carried out according to DIN EN ISO 1567 served to determine flexural strength, flexural modulus, and water adsorption. Polymerization shrinkage was determined via the buoyancy test. RESULTS: The resins' flexural strength ranged from 60 to 101 MPa. Flexural moduli lay between 1.3 and 5.3 GPa. The water adsorption noted in light-cured resins amounted to 2.1-4.6 mass percent. Palapress and Steady-Resin displayed the lowest water adsorption with 2.0 mass percent. The light-polymerized resins revealed significantly less shrinkage (p < 0.05) than the autopolymerized resins tested in this study. CONCLUSION: Our results demonstrate that the light-cured resins-with the exception of Acrylight -easily match and even exceed the material properties of the cold-polymerized resins regarding flexural strength, flexural modulus, water adsorption and polymerization shrinkage. The light-cured resins examined thus seem suitable for use as splint material.

• In-vitro investigation on suitability of light-cured resins for interocclusal splints : part II: surface hardness.

  Authors: Gholamreza Danesh, Carsten Lippold, Thomas Ziebura, Klaus-Jürgen Reinhardt, Edgar Schäfer, Ulrike Ehmer

  Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie. 03/2006; 67(2):138-47.

  OBJECTIVE: The aim of the present study was to determine the surface hardness of light- and auto-cured resins for the fabrication of occlusal splints employing Vickers hardness measurements.OBJECTIVE: The aim of the present study was to determine the surface hardness of light- and auto-cured resins for the fabrication of occlusal splints employing Vickers hardness measurements. MATERIALS AND METHOD: In this study we used three auto-polymerized resins (Palapress, Orthocryl, Steady-Resin M) and four light-polymerized resins (Acrylight, Primosplint, Triad Tran- Sheet Colorless and Triad TranSheet Pink). The Vickers hardness measurement was carried out by means of a universal Durimet indenter applying a test load of 50 g for 30 seconds. The light-cured resins were polymerized in a Tagris Power light oven for 10 and 15 minutes each. Three separate test series were carried out (the hardness of plates under optimal conditions and of occlusal splints was measured, and the curing of light-polymerizing materials in layers of varying depth was evaluated). Data underwent statistical analysis via ANOVA and the Scheffé test. RESULTS: The microhardness determined in each case amounted to values between 10.4 HV 0.5 and 39.3 HV 0.5. The Vickers hardness determined for the plates that had been produced under optimal conditions demonstrated that their surface was significantly (p < 0.05) harder than that of cylinders and splints. The hardness values of the light-cured material Triad TranSheet Pink (39.3 HV 0.5) were significantly higher (p < 0.05) than those of all other resins. In all auto-polymerized resins, the surface hardness of the samples we examined (in the form of plates and splints) was significantly lower (p < 0.05) than that of the light-cured materials Triad TranSheet Pink and Colorless. CONCLUSION: The results we have obtained so far concerning surface hardness indicate that, in the fabrication of occlusal splints, light-cured resins may represent an alternative to auto-polymerizing materials.

• Sagittal jaw position in relation to body posture in adult humans--a rasterstereographic study.

  Authors: Carsten Lippold, Gholamreza Danesh, Markus Schilgen, Burkhard Drerup, Lars Hackenberg

  BMC musculoskeletal disorders. 02/2006; 7:8.

  BACKGROUND: The correlations between the sagittal jaw position and the cranio-cervical inclination are described in literature. Only few studies focus on the sagittal jaw position and the bodyBACKGROUND: The correlations between the sagittal jaw position and the cranio-cervical inclination are described in literature. Only few studies focus on the sagittal jaw position and the body posture using valid and objective orthopaedic examination methods. The aim of this study was to test the hypothesis that patients with malocclusions reveal significant differences in body posture compared to those without (upper thoracic inclination, kyphotic angle, lordotic angle and lower lumbar inclination). METHODS: Eighty-four healthy adult patients (with a mean age = 25.6 years and ranging from 16.1 to 55.8 years) were examined with informed consent. The orthodontic examination horizontal overjet (distance between upper and lower incisors) was determined by using an orthodontic digital sliding calliper. The subjects were subdivided in respect of the overjet with the following results: 18 revealed a normal overjet (Class I), 38 had an increased overjet (Class II) and 28 had an reversed overjet (Class III). Rasterstereography was used to carry out a three-dimensional back shape analysis. This method is based on photogrammetry. A three-dimensional shape was produced by analysing the distortion of parallel horizontal white light lines projected on the patient's back, followed by mathematical modelling. On the basis of the sagittal profile the upper thoracic inclination, the thoracic angle, the lordotic angle and the pelvic inclination were determined with a reported accuracy of 2.8 degrees and the correlations to the sagittal jaw position were calculated by means of ANOVA, Scheffé and Kruskal-Wallis procedures. RESULTS: Between the different overjet groups, no statistically significant differences or correlations regarding the analysed back shape parameters could be obtained. However, comparing males and females there were statistically significant differences in view of the parameters 'lordotic angle' and 'pelvic inclination'. CONCLUSION: No correlations between overjet and variables of the thoracic, lordotic or the pelvic inclination could be observed.

• Potential and limitations of cephalometric analysis of maxillofacial bone movement in the case of LeFort III-distraction.

  Authors: Carsten Lippold, Gholamreza Danesh, Ulrich Meyer, Ariane Hohoff, Matthias Kelker, Johannes Kleinheinz

  Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie. 10/2005; 66(5):388-96.

  BACKGROUND UND METHOD: The treatment of craniofacial deformities by means of distraction osteogenesis has become an established therapeutic procedure. Evaluation of the success of an operation isBACKGROUND UND METHOD: The treatment of craniofacial deformities by means of distraction osteogenesis has become an established therapeutic procedure. Evaluation of the success of an operation is usually carried out via conventional cephalometry. Conventional forms of analysis seem problematic due to surgically-induced changes in the skull base. In this study we investigated the movement of the midface in the presence of a syndromerelated surgical indication employing two different types of analysis, namely those of Ricketts and Delaire. RESULTS: It seems that neither procedure is suitable for determining this type of bone movement conclusively. Comparing the two, the Delaire analysis possessed greater informative value in view of the altered geometry, and a combination of both procedures made more exact determination possible of the final position achieved.

• Effectiveness of Carisolv compared with sodium hypochlorite and calcium hydroxide.

  Authors: Till Dammaschke, Monika Eickmeier, Edgar Schäfer, Gholamreza Danesh, Klaus Heinrich Reiner Ott

  Acta odontologica Scandinavica. 05/2005; 63(2):110-4.

  The aim of this study was to compare the effectiveness of Carisolv with that of two other alkaline substances: NaOCl and Ca(OH)2. Sixty extracted teeth were randomly divided into three groups andThe aim of this study was to compare the effectiveness of Carisolv with that of two other alkaline substances: NaOCl and Ca(OH)2. Sixty extracted teeth were randomly divided into three groups and split down the center of a carious lesion. In group I, one half of the cavity was excavated with NaOCl (0.5%, pH 11.7), the corresponding half with Ca(OH)2 (pH 12.4); in group II with NaOCl and Carisolv; and in group III with Ca(OH)2 and Carisolv (n = 20 in each case). Carisolv hand instruments were used. Histological specimens were subsequently produced from all cavities and analyzed with a light-microscope following Mallory-Azan staining. The thickness of the remaining caries was measured (< 1 mm or > 1 mm) and the locations were recorded. The data were statistically evaluated using the chi-square test. In group I, 50.5% of the specimens treated with NaOCI and 48.7% treated with Ca(OH)2 were evaluated to be caries-free. The results in group II were NaOCl 61.5% and Carisolv 75.4% caries-free, and in group III Ca(OH)2 61.2% and Carisolv 73.9%. No statistically significant differences were found between NaOCl and Ca(OH)2 excavation (group I: p = 0.89). Compared to NaOCl and Ca(OH)2, Carisolv produced significantly better results for chemo-mechanical caries removal (groups II + III: p < 0.05). In the NaOCl and Ca(OH)2 treated specimens, carious layers with a thickness >1 mm were found significantly more often than in the Carisolv-treated specimens (groups II + III: p < 0.05), whereas there were no differences between NaOCl and Ca(OH)2 excavation (p = 0.06). There were no statistically significant differences in the location of the remaining caries in any of the groups (p > 0.05).

• Polymerisation characteristics of resin composites polymerised with different curing units.

  Authors: Gholamreza Danesh, Hendrick Davids, Klaus-Jürgen Reinhardt, Klaus Ott, Edgar Schäfer

  Journal of dentistry. 09/2004; 32(6):479-88.

  OBJECTIVES: The aim of this study was to compare the plasma arc light source Apollo 95E and the conventional halogen lamp Elipar Visio regarding a number of polymerisation characteristics ofOBJECTIVES: The aim of this study was to compare the plasma arc light source Apollo 95E and the conventional halogen lamp Elipar Visio regarding a number of polymerisation characteristics of different resin composites. METHODS: Four different resin composites (Arabesk Top, Herculite XRV, Pertac II, Tetric) were irradiated using the Apollo 95E unit for one, two or three cycles of 3 s and using the Elipar Visio unit for 40 s. The investigated polymerisation characteristics were: flexural strength and modulus of elasticity, bond strength to dentine, depth of polymerisation, and quantity of remaining double bonds. The data were treated statistically by analysis of variance and by Scheffé test. RESULTS: The modulus of elasticity and the flexural strength resulting from curing with Apollo 95E for 1 x 3 s were equal to or less than those resulting from curing with Elipar Visio. The bond strength to dentine and the depth of polymerisation with Apollo 95E used for 1 x 3 s were equal to or less than that obtained with the conventional lamp, depending on the resin composite. Irradiation of Herculite XRV resulted in a higher quantity of remaining double bonds than did Elipar Visio. In general, two or three curing cycles of 3 s with Apollo 95E were necessary to produce mechanical properties not significantly worse than with 40 s of conventional curing. CONCLUSIONS: The efficiency of plasma arc curing with Apollo 95E strongly depends on the resin composite. For most resin composites tested, plasma arc curing for 3 s resulted in inferior mechanical properties as compared to conventional curing.

• Temperature rise in the pulp chamber induced by a conventional halogen light-curing source and a plasma arc lamp.

  Authors: Gholamreza Danesh, Hendrick Davids, Sven Duda, Markus Kaup, Klaus Ott, Edgar Schäfer

  American journal of dentistry. 06/2004; 17(3):203-8.

  PURPOSE: To assess and compare the pulp chamber temperature increase during resin-based composite polymerization with two different light-curing units. METHODS: A Class I cavity was prepared in anPURPOSE: To assess and compare the pulp chamber temperature increase during resin-based composite polymerization with two different light-curing units. METHODS: A Class I cavity was prepared in an extracted lower molar under standardized conditions using a specially designed industrial robot system. The dentin layer between the pulp chamber and the floor of the cavity was 1 mm thick. Pulp chamber temperature rises (starting temperature: 20.0 +/- 0.1 degrees C) were recorded for four different series of investigations using both the halogen curing lamp Elipar Visio (light-curing: 40 s) and the plasma arc lamp Apollo 95E (light-curing: 3 seconds): Group A: Operation of the light-curing units directly over the untreated, empty cavity; Group B: Resin-based composite polymerization without previously applied cement base or bonding agent; Group C: Resin-based composite polymerization with a previously applied cement base; Group D: Resin-based composite polymerization with a previously applied bonding agent. In each of the four groups 10 measurements were carried out for every light-curing unit. Data were statistically analyzed using ANOVA, post-hoc Scheffé test and t-test. RESULTS: The lowest temperature increase (0.3 degrees C) was recorded during composite polymerization with a previously applied cement base using the Apollo 95E unit (Group C, P < 0.05). The highest temperature increase was induced when using the Elipar Visio unit directly over the untreated cavity (Group A, P < 0.05). In Groups A, C and D higher pulp chamber temperature measurements were obtained when using the Elipar Visio unit as compared to the Apollo 95E plasma arc lamp (P < 0.01). In Group B, no significant differences were recorded during the composite polymerization when using the two different light-curing units (P > 0.05).

• Bending properties of rotary nickel-titanium instruments.

  Authors: Edgar Schäfer, Anita Dzepina, Gholamreza Danesh

  Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. 12/2003; 96(6):757-63.

  OBJECTIVE: We sought to compare the bending properties of different rotary nickel-titanium instruments and to investigate the correlation between their bending moments and their cross-sectionalOBJECTIVE: We sought to compare the bending properties of different rotary nickel-titanium instruments and to investigate the correlation between their bending moments and their cross-sectional surface areas. STUDY DESIGN: Resistance to bending was determined according to International Standards Organization publication 3630-1. The sample size was 10 files for each type, taper, and size. The cross-sectional surface area of all instruments was determined by using scanning electron microscope photographs of the cross section. The images were scanned and the area was calculated by using special software. Data were analyzed by using analysis of variance and the Student t test and the Newman-Keuls test for all pairwise comparisons. The strength of the correlation between the bending moment and the cross-sectional area was determined by computing the Pearson product moment correlation. RESULTS: Bending moments were significantly lower for ProFile and RaCe files than for all other files (P <.05). K3 files were significantly less flexible than all other instruments (P <.05). The correlation between stiffness and cross-sectional area was highly significant (r = 0.928; P <.0001). CONCLUSION: Nickel-titanium files with tapers greater than.04 should not be used for apical enlargement of curved canals because these files are considerably stiffer than are those with.02 or.04 tapers.

• Interdisciplinary study of orthopedic and orthodontic findings in pre-school infants.

  Authors: Carsten Lippold, Louwrens van den Bos, Ariane Hohoff, Gholamreza Danesh, Ulrike Ehmer

  Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie. 10/2003; 64(5):330-40.

  BACKGROUND AND AIM: The assessment of correlations between orthopedic and orthodontic data based on interdisciplinary studies is of scientific and practical interest in the differentiation ofBACKGROUND AND AIM: The assessment of correlations between orthopedic and orthodontic data based on interdisciplinary studies is of scientific and practical interest in the differentiation of preventive diagnostic and therapeutic fields between orthodontics and orthopedics. In the published literature there are various studies analyzing the correlations between specific Angle classes and orthopedic parameters. Results of these studies indicate a potential correlation between scoliosis and Class II malocclusion as well as between weak body posture and Class II malocclusion. The aim of the present interdisciplinary study was to examine correlations between orthodontic and orthopedic findings in pre-school infants and to evaluate them with respect to preventive recommendations. PATIENTS AND METHOD: 59 pre-school infants (29 boys, 30 girls) aged 3.5-6.8 years (mean: 5.0 years) were enrolled in this study. A standardized orthodontic and orthopedic examination protocol was used. RESULTS: The orthodontic examination showed Angle class distributions comparable with those in non-selected groups (Class I: 63%, Class II: 32%, Class III: 5%). The orthopedic examination revealed pathologic findings in 52% of the subjects, with statistically significant correlations between scoliosis and Class II malocclusion (p = 0.033) and between weak body posture and Class II malocclusion (p = 0.028). CONCLUSION: It can be concluded from the results that the orthodontic finding of Angle Class II in pre-school infants should induce prophylactic screening. The orthodontist could then not only initiate early orthodontic treatment to prevent incisor trauma in patients with extreme overjet, but could also take account of potential orthopedic malformations on a preventive interdisciplinary basis in pre-school infants with Class II malocclusions.

• Treatment of hemimandibular hyperplasia: The biological basis of condylectomy

  Authors: Carsten Lippold, Birgit Kruse-Losler, Gholamreza Danesh, Ulrich Joos, Ulrich Meyer

  British Journal of Oral and Maxillofacial Surgery.

  Treatments to correct skeletal deformities in patients with hemimandibular hyperplasia differ, particularly about the age at which the operation is done and the operation itself. To some extent, theTreatments to correct skeletal deformities in patients with hemimandibular hyperplasia differ, particularly about the age at which the operation is done and the operation itself. To some extent, the differences can be attributed to the unknown biological basis of disease. The aim of the present study was to evaluate clinically the outcome of a rationale for the operation based on condylectomy on the affected side. Histological, radiological, and nuclear methods were used to get a more detailed insight into the reason for the operation. Six patients with hemimandibular hyperplasia were treated by a combined orthodontic-maxillofacial protocol. All patients had the affected joint removed. The histological morphology of each condylar specimen was compared with the bone scintigraphy to try and find a correlation between the methods. The clinical evaluation showed morphological and functional rehabilitation of all six patients. During the 2-year follow-up, all patients had stable symmetrical mandibles with no disturbance of temporomandibular function. Remodelling of the joint and the destruction of the cartilaginous layer was accompanied by much bone scintigraphic activity. We conclude that condylectomy can correct hemimandibular hyperplasia, even in patients with active condylar growth, by removing the underlying disease.