Orthodontic forces have been reported to significantly increase nicotine-induced periodontal bone loss. At present, however, it is unknown, which further (side) effects can be expected during orthodontic treatment a...Orthodontic forces have been reported to significantly increase nicotine-induced periodontal bone loss. At present, however, it is unknown, which further (side) effects can be expected during orthodontic treatment at a nicotine exposure corresponding to that of an average European smoker. 63 male Fischer344 rats were randomized in three consecutive experiments of 21 animals each (A/B/C) to 3 experimental groups (7 rats, 112/3). (A) cone-beam-computed tomography (CBCT); (B) histology/serology; (C) reverse- transcription quantitative real-time polymerase chain reaction (RT-qPCR)/cotinine serology--(1) control; (2) orthodontic tooth movement (OTM) of the first and second upper left molar (NiTi closed coil spring, 0.25 N); (3) OTM with 1.89 mg-kg- 1 per day s.c. of L(- )-nicotine. After 14 days of OTM, serum cotinine and IL-6 concentration as well as orthodontically induced inflammatory root resorption (OIIRR), osteoclast activity (histology), orthodontic tooth movement velocity (CBCT, within 14 and 28 days of OTM) and relative gene expression of known inflammatory and osteoclast markers were quantified in the dental-periodontal tissue (RT-qPCR). Animals exposed to nicotine showed significantly heightened serum cotinine and IL-6 levels corresponding to those of regular European smokers. Both the extent of root resorption, osteoclast activity, orthodontic tooth movement and gene expression of inflammatory and osteoclast markers were significantly increased compared to controls with and without OTM under the influence of nicotine. We conclude that apart from increased periodontal bone loss, a progression of dental root resorption and accelerated orthodontic tooth movement are to be anticipated during orthodontic therapy, if nicotine consumption is present. Thus patients should be informed about these risks and the necessity of nicotine abstinence during treatment.展开更多
During orthodontic tooth movement(OTM)mechanical forces trigger pseudo-inflammatory,osteoclastogenic and remodelling processes in the periodontal ligament(PDL)that are mediated by PDL fibroblasts via the expression of...During orthodontic tooth movement(OTM)mechanical forces trigger pseudo-inflammatory,osteoclastogenic and remodelling processes in the periodontal ligament(PDL)that are mediated by PDL fibroblasts via the expression of various signalling molecules.Thus far,it is unknown whether these processes are mainly induced by mechanical cellular deformation(mechanotransduction)or by concomitant hypoxic conditions via the compression of periodontal blood vessels.Human primary PDL fibroblasts were randomly seeded in conventional six-well cell culture plates with O2-impermeable polystyrene membranes and in special plates with gas-permeable membranes(Lumox?,Sarstedt),enabling the experimental separation of mechanotransducive and hypoxic effects that occur concomitantly during OTM.To simulate physiological orthodontic compressive forces,PDL fibroblasts were stimulated mechanically at 2 g·cm?2 for 48 h after 24 h of pre-incubation.We quantified the cell viability by MTT assay,gene expression by quantitative real-time polymerase chain reaction(RT-qPCR)and protein expression by western blot/enzyme-linked immunosorbent assays(ELISA).In addition,PDL-fibroblast-mediated osteoclastogenesis(TRAP+cells)was measured in a 72-h coculture with RAW264.7 cells.The expression of HIF-1α,COX-2,PGE2,VEGF,COL1A2,collagen and ALPL,and the RANKL/OPG ratios at the mRNA/protein levels during PDL-fibroblast-mediated osteoclastogenesis were significantly elevated by mechanical loading irrespective of the oxygen supply,whereas hypoxic conditions had no significant additional effects.The cellular–molecular mediation of OTM by PDL fibroblasts via the expression of various signalling molecules is expected to be predominantly controlled by the application of force(mechanotransduction),whereas hypoxic effects seem to play only a minor role.In the context of OTM,the hypoxic marker HIF-1αdoes not appear to be primarily stabilized by a reduced O2 supply but is rather stabilised mechanically.展开更多
The continuously growing esthetic awareness for the facial appearance and the spreading of information about the possibilities of adult treatment by public media result in an increase of adult patients which seek orth...The continuously growing esthetic awareness for the facial appearance and the spreading of information about the possibilities of adult treatment by public media result in an increase of adult patients which seek orthodontic treatment to improve their facial esthetics. In general, these patients show such a severe skeletal deformity that it is detectable even by non-experts because of its extraoral manifestation, which is the main motivation for treatment. Because of the nature of these deformities and because of the lacking growth usable for therapy the only promising treatment for these patients is the combined orthodontic-surgical approach. Besides a stable and functional occlusion with physiologic position of the condyle, the goals of treatment are the improvement of the dental and, above all, facial esthetics since the patient judges the success of treatment mostly by the extraoral appearance. The dentofacial appearance must be defined prior to treatment to plan the individual right approach in knowledge of the different treatment possibilities for Angle Class II deformities and thus be able to reach for both sides—patient and orthodontist—satisfying result. With this article, a systematic therapy concept to treat patients with Class II deformities and skeletal deep bite with a short lower face (short face syndrome) under consideration of the soft tissue analysis is presented.展开更多
Introduction: Following orthognathic surgery, increased tooth mobility is observed clinically and is utilized for postsurgical orthodontic tooth movement. It was suggested that the increase may result from a surgery-a...Introduction: Following orthognathic surgery, increased tooth mobility is observed clinically and is utilized for postsurgical orthodontic tooth movement. It was suggested that the increase may result from a surgery-associated alteration of parathyroid hormone (PTH) and calcium metabolism. Materials and Methods: 30 young adult patients were divided into a mandibular osteotomy group (Group A, n = 20) and an untreated control group (Group B, n = 10). Tooth mobility was evaluated using the Periotest device. Tooth mobility, serum PTH and calcium levels were determined repeatedly for both groups. Results: The tooth mobility was increased significantly in the Group A patients in the first 10 days post-surgery. All serum PTH and calcium mean levels were within normal ranges. No significant differences were found between the measurements of both groups. The serum calcium levels recorded at the 1st post-surgery day were slightly lower in the operated patients compared to the control group. Conclusion: It can be concluded that the increased facility of orthodontic tooth movement immediately post-surgery was confirmed by Periotest measurements, while no association was found with surgery-related altered levels of PTH and calcium. Since dietary effects can be ruled out, the increase of clinical tooth mobility may rather result from preoperative orthodontic forces and/or the post-surgical elimination of masticatory muscular influences.展开更多
The aim of this study was to compare the shear bond strength and Adhesive Remnant Index of four different veneering ceramic materials to metal brackets. Additionally, it should be examined whether it is possible to ov...The aim of this study was to compare the shear bond strength and Adhesive Remnant Index of four different veneering ceramic materials to metal brackets. Additionally, it should be examined whether it is possible to overcome the etching method using hydrofluoric acid which is noxious. Instead of this treatment, air particle abrasion with 25 μm aluminium trioxide, silane coupling application and etching with 37.0 per cent orthophosphoric acid as pre-treatment procedures of the veneering ceramics before bonding was investigated. Two surface conditioning methods of four ceramic materials before bonding brackets were examined: in group 1 an air particle abrasion with 25 μm aluminium trioxide (4 seconds at a pressure of 2.5 bars) and subsequently a silane coupling agent (Espe Sil, 3M Unitek, Monrovia, USA) was applicated on one side of each ceramic specimen (10 per group). In group 2 one side of each sample (10 per group) was etched with 37.0 per cent orthophosphoric acid for two minutes and was followed by a silane application (Espe Sil, 3M Unitek, Monrovia, USA). After this procedure the self-ligating metal brackets SmartClip (3M Unitek, Monrovia, USA) brackets were bonded to the ceramic blocks and a thermocycling process started (5°C - 55°C, 6000 cycles). Then, shear bond strength and Adhesive Remnant Index (ARI) were measured. To determine statistical differences Oneway-ANOVA and Tukey Post-hoc test were performed. The level of significance was set at α = 0.05. On the basis of the results of the current study, it could be concluded that sandblasting with 25 μm aluminium trioxide and the use of orthophosphoric acid (37.0 per cent) seem to prepare the surface of the ceramic restoration sufficiently before bracket bonding. The found level of shear bond strength values seem be sufficient for bracket bonding. Hydrofluoric acid seems not to be justifiable anymore for preparing the surface of dental ceramic restorations before bracket bonding.展开更多
The purpose of this study was to compare the shear bond strength and Adhesive Remnant Index of four different veneering ceramic materials to ceramic brackets. Additionallly, a further aim of this study was to overcome...The purpose of this study was to compare the shear bond strength and Adhesive Remnant Index of four different veneering ceramic materials to ceramic brackets. Additionallly, a further aim of this study was to overcome the etching using hydrofluoric acid which is noxious and could seriously damage the corneas of the eyes. Two surface conditioning methods of four ceramic materials before bonding brackets were examined: in group 1 an air particle abrasion with 25 μm aluminium trioxide (4 seconds at a pressure of 2.5 bars) and subsequently a silane coupling agent (Espe Sil, 3M Unitek, Monrovia, USA) was applicated on one side of each ceramic specimen (10 per group). In group 2 one side of each sample (20 per group) was etched with 37.0 per cent orthophosphoric acid for two minutes and was followed by a silane application (Espe Sil, 3M Unitek, Monrovia, USA). After this procedure the self-ligating ceramic brackets Clarity SL (3M Unitek, Monrovia, USA) brackets were bonded to the ceramic blocks and a thermocycling process started (5°C - 55°C, 6000 cycles). Then, shear bond strength and Adhesive Remnant Index (ARI) were measured. To determine statistical differences Oneway-ANOVA and Tukey Post-hoc test were performed. Hydrofluoric acid seems not to be justifiable anymore for preparing the surface of dental ceramic restorations before bracket bonding. Sandblasting with 25 μm aluminium trioxide and the use of orthophosphoric acid (37.0 per cent) seem to prepare the surface of ceramic restoration sufficiently before ceramic bracket bonding. The found level of shear bond strength values seems to be sufficient for bonding ceramic brackets to ceramic restorations.展开更多
基金the ReForM-A-research funding programme of the Faculty of Medicine(University of Regensburg)for their financial supportsupported by a ReForM-A grant from the ReForM research funding programme of the Faculty of Medicine of the University of Regensburg,Germany(Kirschneck 31 March 2015)the German Research Foundation(DFG)within the funding programme Open Access Publishing
文摘Orthodontic forces have been reported to significantly increase nicotine-induced periodontal bone loss. At present, however, it is unknown, which further (side) effects can be expected during orthodontic treatment at a nicotine exposure corresponding to that of an average European smoker. 63 male Fischer344 rats were randomized in three consecutive experiments of 21 animals each (A/B/C) to 3 experimental groups (7 rats, 112/3). (A) cone-beam-computed tomography (CBCT); (B) histology/serology; (C) reverse- transcription quantitative real-time polymerase chain reaction (RT-qPCR)/cotinine serology--(1) control; (2) orthodontic tooth movement (OTM) of the first and second upper left molar (NiTi closed coil spring, 0.25 N); (3) OTM with 1.89 mg-kg- 1 per day s.c. of L(- )-nicotine. After 14 days of OTM, serum cotinine and IL-6 concentration as well as orthodontically induced inflammatory root resorption (OIIRR), osteoclast activity (histology), orthodontic tooth movement velocity (CBCT, within 14 and 28 days of OTM) and relative gene expression of known inflammatory and osteoclast markers were quantified in the dental-periodontal tissue (RT-qPCR). Animals exposed to nicotine showed significantly heightened serum cotinine and IL-6 levels corresponding to those of regular European smokers. Both the extent of root resorption, osteoclast activity, orthodontic tooth movement and gene expression of inflammatory and osteoclast markers were significantly increased compared to controls with and without OTM under the influence of nicotine. We conclude that apart from increased periodontal bone loss, a progression of dental root resorption and accelerated orthodontic tooth movement are to be anticipated during orthodontic therapy, if nicotine consumption is present. Thus patients should be informed about these risks and the necessity of nicotine abstinence during treatment.
基金German Research Foundation(DFG)for their financial supportfunding of this study(grant number KI 2105/1-1)
文摘During orthodontic tooth movement(OTM)mechanical forces trigger pseudo-inflammatory,osteoclastogenic and remodelling processes in the periodontal ligament(PDL)that are mediated by PDL fibroblasts via the expression of various signalling molecules.Thus far,it is unknown whether these processes are mainly induced by mechanical cellular deformation(mechanotransduction)or by concomitant hypoxic conditions via the compression of periodontal blood vessels.Human primary PDL fibroblasts were randomly seeded in conventional six-well cell culture plates with O2-impermeable polystyrene membranes and in special plates with gas-permeable membranes(Lumox?,Sarstedt),enabling the experimental separation of mechanotransducive and hypoxic effects that occur concomitantly during OTM.To simulate physiological orthodontic compressive forces,PDL fibroblasts were stimulated mechanically at 2 g·cm?2 for 48 h after 24 h of pre-incubation.We quantified the cell viability by MTT assay,gene expression by quantitative real-time polymerase chain reaction(RT-qPCR)and protein expression by western blot/enzyme-linked immunosorbent assays(ELISA).In addition,PDL-fibroblast-mediated osteoclastogenesis(TRAP+cells)was measured in a 72-h coculture with RAW264.7 cells.The expression of HIF-1α,COX-2,PGE2,VEGF,COL1A2,collagen and ALPL,and the RANKL/OPG ratios at the mRNA/protein levels during PDL-fibroblast-mediated osteoclastogenesis were significantly elevated by mechanical loading irrespective of the oxygen supply,whereas hypoxic conditions had no significant additional effects.The cellular–molecular mediation of OTM by PDL fibroblasts via the expression of various signalling molecules is expected to be predominantly controlled by the application of force(mechanotransduction),whereas hypoxic effects seem to play only a minor role.In the context of OTM,the hypoxic marker HIF-1αdoes not appear to be primarily stabilized by a reduced O2 supply but is rather stabilised mechanically.
文摘The continuously growing esthetic awareness for the facial appearance and the spreading of information about the possibilities of adult treatment by public media result in an increase of adult patients which seek orthodontic treatment to improve their facial esthetics. In general, these patients show such a severe skeletal deformity that it is detectable even by non-experts because of its extraoral manifestation, which is the main motivation for treatment. Because of the nature of these deformities and because of the lacking growth usable for therapy the only promising treatment for these patients is the combined orthodontic-surgical approach. Besides a stable and functional occlusion with physiologic position of the condyle, the goals of treatment are the improvement of the dental and, above all, facial esthetics since the patient judges the success of treatment mostly by the extraoral appearance. The dentofacial appearance must be defined prior to treatment to plan the individual right approach in knowledge of the different treatment possibilities for Angle Class II deformities and thus be able to reach for both sides—patient and orthodontist—satisfying result. With this article, a systematic therapy concept to treat patients with Class II deformities and skeletal deep bite with a short lower face (short face syndrome) under consideration of the soft tissue analysis is presented.
文摘Introduction: Following orthognathic surgery, increased tooth mobility is observed clinically and is utilized for postsurgical orthodontic tooth movement. It was suggested that the increase may result from a surgery-associated alteration of parathyroid hormone (PTH) and calcium metabolism. Materials and Methods: 30 young adult patients were divided into a mandibular osteotomy group (Group A, n = 20) and an untreated control group (Group B, n = 10). Tooth mobility was evaluated using the Periotest device. Tooth mobility, serum PTH and calcium levels were determined repeatedly for both groups. Results: The tooth mobility was increased significantly in the Group A patients in the first 10 days post-surgery. All serum PTH and calcium mean levels were within normal ranges. No significant differences were found between the measurements of both groups. The serum calcium levels recorded at the 1st post-surgery day were slightly lower in the operated patients compared to the control group. Conclusion: It can be concluded that the increased facility of orthodontic tooth movement immediately post-surgery was confirmed by Periotest measurements, while no association was found with surgery-related altered levels of PTH and calcium. Since dietary effects can be ruled out, the increase of clinical tooth mobility may rather result from preoperative orthodontic forces and/or the post-surgical elimination of masticatory muscular influences.
文摘The aim of this study was to compare the shear bond strength and Adhesive Remnant Index of four different veneering ceramic materials to metal brackets. Additionally, it should be examined whether it is possible to overcome the etching method using hydrofluoric acid which is noxious. Instead of this treatment, air particle abrasion with 25 μm aluminium trioxide, silane coupling application and etching with 37.0 per cent orthophosphoric acid as pre-treatment procedures of the veneering ceramics before bonding was investigated. Two surface conditioning methods of four ceramic materials before bonding brackets were examined: in group 1 an air particle abrasion with 25 μm aluminium trioxide (4 seconds at a pressure of 2.5 bars) and subsequently a silane coupling agent (Espe Sil, 3M Unitek, Monrovia, USA) was applicated on one side of each ceramic specimen (10 per group). In group 2 one side of each sample (10 per group) was etched with 37.0 per cent orthophosphoric acid for two minutes and was followed by a silane application (Espe Sil, 3M Unitek, Monrovia, USA). After this procedure the self-ligating metal brackets SmartClip (3M Unitek, Monrovia, USA) brackets were bonded to the ceramic blocks and a thermocycling process started (5°C - 55°C, 6000 cycles). Then, shear bond strength and Adhesive Remnant Index (ARI) were measured. To determine statistical differences Oneway-ANOVA and Tukey Post-hoc test were performed. The level of significance was set at α = 0.05. On the basis of the results of the current study, it could be concluded that sandblasting with 25 μm aluminium trioxide and the use of orthophosphoric acid (37.0 per cent) seem to prepare the surface of the ceramic restoration sufficiently before bracket bonding. The found level of shear bond strength values seem be sufficient for bracket bonding. Hydrofluoric acid seems not to be justifiable anymore for preparing the surface of dental ceramic restorations before bracket bonding.
文摘The purpose of this study was to compare the shear bond strength and Adhesive Remnant Index of four different veneering ceramic materials to ceramic brackets. Additionallly, a further aim of this study was to overcome the etching using hydrofluoric acid which is noxious and could seriously damage the corneas of the eyes. Two surface conditioning methods of four ceramic materials before bonding brackets were examined: in group 1 an air particle abrasion with 25 μm aluminium trioxide (4 seconds at a pressure of 2.5 bars) and subsequently a silane coupling agent (Espe Sil, 3M Unitek, Monrovia, USA) was applicated on one side of each ceramic specimen (10 per group). In group 2 one side of each sample (20 per group) was etched with 37.0 per cent orthophosphoric acid for two minutes and was followed by a silane application (Espe Sil, 3M Unitek, Monrovia, USA). After this procedure the self-ligating ceramic brackets Clarity SL (3M Unitek, Monrovia, USA) brackets were bonded to the ceramic blocks and a thermocycling process started (5°C - 55°C, 6000 cycles). Then, shear bond strength and Adhesive Remnant Index (ARI) were measured. To determine statistical differences Oneway-ANOVA and Tukey Post-hoc test were performed. Hydrofluoric acid seems not to be justifiable anymore for preparing the surface of dental ceramic restorations before bracket bonding. Sandblasting with 25 μm aluminium trioxide and the use of orthophosphoric acid (37.0 per cent) seem to prepare the surface of ceramic restoration sufficiently before ceramic bracket bonding. The found level of shear bond strength values seems to be sufficient for bonding ceramic brackets to ceramic restorations.