ABSTRACT
The enamel can be protected by applying orthodontic sealants at the bracket base to avoid the development of white spot lesions caused by inadequate oral hygiene. The aim of this study was to investigate the mechanical resistance of five commonly used orthodontic sealants against brushing in comparison to a positive group. Hydroxyapatite discs were bonded with a metal bracket and a piece of arch-wire was ligated in order to simulate a daily clinical situation (n = 48). Samples were divided into 6 groups of respectively 8 specimens. Sealants were applied around the bracket base according to manufacturer's instructions. Following sealants were used: Group 1: Pro Seal (Reliance Orthodontic Products, Itasca, Illinois, USA); 2: Light Bond (Reliance Orthodontic Products, Itasca, Illinois, USA); 3: ClinproXT Varnish (3M ESPE, Seefeld, Germany); 4: ProtectoCaF2 Nano (BonaDent GmbH, Frankfurt am Main, Germany); 5: Fluor Protector and 6: Tetric EvoFlow (both Ivoclar Vivadent AG, Schaan Liechtenstein). Tooth brushing were simulated for 6 weeks and 6 months with an electric toothbrush. The sealant thickness was measured by mechanical (MP) and optical profilometry (OP) at baseline, after 6 weeks and after 6 months of brushing. Statistical analysis was performed according to two mixed linear models and post hoc Tukey-Kramer comparisons. The significance level was set at 5% (α ≤ 0.05). Pro Seal (MP: 9%; OP: 22%) and Light Bond (MP: 19%; OP: 16%) showed the lowest changes in sealant thickness after 6 months of simulated brushing. ClinproXT Varnish and Tetric EvoFlow recorded no statistically significant results (p > 0.05). The fluoride varnishes ProtectoCaF2 Nano and Fluor Protector could not be conclusively evaluated since the thickness of the sealants could not be determined at baseline. The results of both evaluation methods MP and OP are in good agreement. Pro Seal and Light Bond were resistant against tooth brushing and were able to adequately keep the bracket environment sealed even after 6 months. The two different measuring methods, MP and OP, provide a precise impression of the changes in the surface.
Subject(s)
Fluorides, Topical , Orthodontic Brackets , Fluorides , Germany , Hydroxyapatites , ToothbrushingABSTRACT
OBJECTIVES: The aim of this study was to investigate and compare the changes in human periodontal ligament fibroblasts (HPdLFs) and osteoblasts (HOBs) after the application of compressive force (CF) at two different strengths in vitro. MATERIALS AND METHODS: HPdLF and HOB were exposed to CF with various strengths (5 and 10 %) using a Flexercell Compression Unit for 12 h in vitro. Viability was detected via 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide (MTT) and apoptosis rate by transferase dUTP nick end labeling (TUNEL) assay. The gene expression of alkaline phosphatase (ALP), osteocalcin (OCN), osteoprotegerin (OPG), and receptor activator of NF-κB ligand (RANKL) was analyzed using reverse transcriptase polymerase chain reaction (RT-PCR). Osteopontin (OPN), matrix metalloproteinase-8 (MMP-8), and tissue inhibition of metalloproteinase-1 (TIMP-1) were quantified by an ELISA. RESULTS: Ten percent CF decreased viability, particularly in HOBs, but did not induce increased apoptosis. ALP gene expression increased the most after 5 % CF in HPdLFs and after 10 % CF in HOB. OCN was not affected by CF in either cell line. The highest RANKL/OPG ratio was measured after 5 % CF in both cell lines. OPN was upregulated in HOB by 5 %. HPdLFs showed an upregulation of MMP-8-synthesis and an increased MMP-8/TIMP-1 ratio. CONCLUSIONS: HOBs have a greater effect on bone remodeling through the upregulation of OPN, whereas HPdLFs facilitate orthodontic tooth movement by influencing the extracellular matrix via the MMP-8/TIMP-1 ratio. CLINICAL RELEVANCE: High CF in orthodontics should be avoided to prevent tissue damage, whereas moderate CF enables active tissue remodeling and tooth movement.
Subject(s)
Fibroblasts/physiology , Osteoblasts/physiology , Periodontal Ligament/cytology , Stress, Mechanical , Apoptosis , Biomechanical Phenomena , Cell Survival , Enzyme-Linked Immunosorbent Assay , Fibroblasts/chemistry , Humans , In Situ Nick-End Labeling , In Vitro Techniques , Osteoblasts/chemistry , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Long-term prophylaxis achievements, demographic changes, scientific progress, patient requirements, and political regulations through social legislation will fundamentally change the future of orthodontics, i.e., a reduction in children and adolescent therapy as well as an increase in interdisciplinary complex treatments for adult patients mostly outside the social security system. Health care research at a high evidence level needs to be intensified due to social-political reasons. In addition to well-proven appliances, modern sometimes even invisible appliances (CAD-CAM) will be used in future orthodontic therapy. Three-dimensional diagnostics could improve treatment planning. Whether improved prenatal diagnosis will alter the number of newborns with dentofacial malformations (cleft lip and palate) or syndromes (e.g., Down syndrome), thus, changing treatment needs in the future, cannot be predicted today, due to the multiple influencing factors. A well-structured 4-year specialist training according to European guidelines will also be necessary in the future to comply with complex treatment needs be it within or outside the social security system (quality assurance).
Subject(s)
Malocclusion/rehabilitation , National Health Programs/trends , Orthodontics/trends , Adolescent , Adult , Aged , Child , Cleft Lip/rehabilitation , Cleft Palate/rehabilitation , Curriculum/trends , Education, Dental, Graduate/trends , Forecasting , Germany , Humans , Malocclusion/complications , Malocclusion/etiology , Middle Aged , Orthodontic Appliances/trends , Orthodontics/education , Population Dynamics , Quality Assurance, Health Care/trends , Treatment Outcome , Young AdultABSTRACT
AIM: This case report describes a treatment method for distalisation and uprighting of first permanent maxillary molars with the aim of preventing complications in the presence of undermining resorption of the second deciduous molar. We present a fixed appliance, which is a compliance-independent and effective alternative to the methods used thus far such as removable plates with distal screws or separating ligatures.
Subject(s)
Molar/pathology , Tooth Eruption, Ectopic/therapy , Tooth Movement Techniques/methods , Tooth Resorption/complications , Tooth, Deciduous/pathology , Biomechanical Phenomena , Child , Dentition, Mixed , Elastomers/chemistry , Female , Humans , Maxilla , Orthodontic Appliance Design , Orthodontic Brackets , Orthodontic Wires , Tooth Movement Techniques/instrumentationABSTRACT
OBJECTIVE: The aim of this study was to develop a measure of childhood information learning experiences related to dental anxiety according to Rachmnan's theory of fear acquisition entitled "Dental Information Learning History Questionnaire (DILHQ)" and to determine its test quality with regard to factorial validity, reliability, divergent, discriminant, and predictive validity. METHOD: Sample 1 included 228 dental patients, answering a 17-item-pool of the DILHQ, the Dental Anxiety Scale (DAS: Corah, 1969), and the Self-Consciousness Scale by Fenigstein et al. (1975). A second sample of 197 patients filled in the final 12-item test version, the DAS and the state version of the State-Trait Anxiety Inventory (Spielberger et al., 1970). Ninety-five participants constituting the third sample answered the DILHQ twice with a 14-days interval. RESULTS: An exploratory study using the first sample resulted in two dimensions underlying the DILHQ-answers after removal of the unique loading items. The two-factorial structure was confirmed in the second sample. The factor-analytically derived Danger Information and Acceptance Information subscales showed sufficient internal consistency (Alpha = 0.87 and 0.72) and temporal stability (r(tt) = 0.77 and 0.76). Dentally fearful patients remembered being exposed to more danger information and less acceptance information about dentistry during childhood than low-fearful patients did (p < 0.001 each). Danger information and acceptance information predicted anxious response to the following dental procedure in opposite directions (r = 0.29 and r = -0.29). CONCLUSION: The results suggest that the DILHQ fulfils criteria of good construct validity. Exposure to threatening information about dentistry during childhood may increase the risk for dental fear acquisition and for exaggerated anxious response to treatment, while acceptance information might have a protective effect.
Subject(s)
Avoidance Learning , Dental Anxiety/etiology , Personality Inventory/statistics & numerical data , Surveys and Questionnaires , Adult , Discriminant Analysis , Factor Analysis, Statistical , Female , Humans , Least-Squares Analysis , Linear Models , Male , Manifest Anxiety Scale , Predictive Value of Tests , Psychometrics , Self ConceptABSTRACT
OBJECTIVE: The aim of this study was to investigate experimentally the positional stability and histomorphometric findings of length-reduced temporary anchorage devices (Orthosystem, length: 4 mm) with reduced sink depth. MATERIAL AND METHODS: For this purpose, four maxillary pre-molars ((2)P(2), (3)P(3)) were extracted from each of four foxhounds. After a 16-week alveolar healing period, 16 implants (four per dog) were inserted into the edentulous areas. Four implants (one per dog) were placed simultaneously in the mid-palatal area. The implants were intentionally submerged to about three-quarters of their length. After a 10-week unloaded implant healing period, the implants in the P3 areas and the palate were loaded (test implants) by means of transpalatal bars fixed on the implants in the P3 areas and Sentalloy traction springs ( approximately 2 N continuous force) inserted mid-sagittally between palatal implants and bars (force application period: 24 weeks). The implants in the P2 areas served as controls. RESULTS: Clinical measurements and histological evaluation revealed positional stability of the loaded fixtures. Alveolar control implants (ACI) were inserted to a mean depth of 3.2 mm, alveolar test implants (ATI) to 3.3 mm and palatal test implants (PTI) to 2.6 mm. The mean direct bone contact percentage values were 71.3% (ACI), 79.6% (ATI) and 72.2% (PTI). CONCLUSION: These results suggest that, probably due to the relatively high percentage of bone contact with implant surface, only 3 mm of intrabony implant length is sufficient to retain positional stability during long-term orthodontic loading.
Subject(s)
Dental Implants , Maxilla/surgery , Orthodontic Anchorage Procedures/instrumentation , Orthodontic Appliance Design , Alveolar Process/pathology , Animals , Bicuspid , Bone Marrow/pathology , Bone Remodeling/physiology , Bone Screws , Dogs , Equipment Failure , Male , Maxilla/pathology , Orthodontic Appliances , Orthodontic Wires , Osseointegration/physiology , Palate/pathology , Palate/surgery , Stress, Mechanical , Surface Properties , Time FactorsABSTRACT
The purpose of this study was to evaluate, histologically, root contact, proximity to a root, and proximity to marginal bone level as possible risk factors for the failure of mini-screws when inserted between neighbouring teeth. Twenty mini-screws were inserted into the mandible of five beagle dogs. Each dog received two bracket screw bone anchors in each lower quadrant, between the roots of the second and third, and third and fourth premolars. Every six weeks, apical radiographs were taken and vital stains were administered. Twenty-five weeks after insertion of the screws, the dogs were sacrificed and specimens prepared for histological evaluation. The distance between the screw and the roots and between the screw and the marginal ridge level (MRL) were measured on the histological slides. The presence or absence of root contact was evaluated histologically on serial sections. The number of screws was too small to allow for sound statistical analysis of the factors under investigation. During the evaluation period, 11 screws were lost. Six screws were in contact with a tooth root and five of these were lost. In five sites, the distance between the screw and the tooth was less than 1.0 mm, but only one of these screws was lost. The distance between the screw and the marginal bone level was less than 1.0 mm for nine screws and seven of these were lost. The results of this limited study suggest that root contact and marginal position might be major risk factors for screw failure.
Subject(s)
Bone Screws/adverse effects , Dental Restoration Failure , Orthodontic Anchorage Procedures/instrumentation , Osseointegration/physiology , Tooth Root/injuries , Animals , Dental Implantation, Endosseous/instrumentation , Dental Stress Analysis , Dogs , Male , Risk Factors , Tooth Root/physiology , Weight-BearingABSTRACT
OBJECTIVES: The aim of this study was to develop an instrument measuring core concerns about dental treatment guided by Reiss' expectancy theory of fear. This would include the content domains of injury, somatic reaction and interpersonal concerns, to study the underlying factorial structure, and to determine the test quality of the resulting subscales. METHODS: A total of 555 regular dental patients answered the item pool. Subsamples filled in the Dental Anxiety Scale (DAS) (n = 346) and the Anxiety-Present Scale of the state-form of the State-Trait Anxiety Inventory (STAI-S) (n = 187). A second sample (n = 89) was used to determine test-retest reliability and bias for social desirability [Self Disclosure Scale of the Freiburg Personality Inventory (FPI)]. RESULTS: Exploratory and confirmatory factor analyses identified a stable three-dimensional structure underlying the items convergent to the content domains of interpersonal, injury and somatic reaction concerns. Internal consistencies of the resulting subscales were between alpha = 0.84 and alpha = 0.87, test-retest reliabilities were from r(tt) = 0.72-0.78. No evidence for a social desirability response bias was found. All subscales discriminated between patients with low and high dental trait anxiety at a level of P < 0.00001. Dental treatment concerns predicted 36% of variations in actual anxiety during treatment. CONCLUSIONS: The results suggest that the proposed instrument, namely the Dental Treatment Concerns Inventory, shows good test qualities according to construct, discriminant and predictive validity, and may be a promising tool for research and clinical applications.
Subject(s)
Dental Anxiety/etiology , Dental Anxiety/psychology , Surveys and Questionnaires , Adult , Dental Care/psychology , Dentist-Patient Relations , Discriminant Analysis , Female , Humans , Male , Manifest Anxiety Scale , Personality Inventory , Predictive Value of Tests , Principal Component Analysis , Regression Analysis , Reproducibility of Results , Self Disclosure , Social DesirabilityABSTRACT
A prospective clinical trial was carried out to compare argon laser-curing of a traditional light-activated composite resin with conventional visible light-curing in terms of bond failure rate and incidence of enamel decalcification. Forty-five patients with a total of 742 metal brackets bonded to the upper and/or lower teeth in a modified split-mouth design participated in the study. The adhesive (Transbond XT) on the control teeth was cured by conventional visible light for 40 seconds, and the experimental teeth were exposed to 10 seconds of 250 mW argon laser irradiation. The patients were monitored for a period of 14 months. Intraoral photographic slides of the maxillary anterior teeth (212 in total) were taken at the beginning of treatment, after 12 months of treatment, following application of a plaque disclosing agent, and at the end of the observation period, following temporary debonding. Seven dentists used standardized rating systems to evaluate decalcification and plaque accumulation. The results of this study indicated that there were no significant differences between curing methods for the incidence of decalcification and plaque accumulation. However, the 10 second argon laser-curing method showed a statistically lower bond failure rate (2.4 per cent, P < 0.05) than the 40 second conventional visible light-curing method (5.7 per cent). It is concluded that the use of argon laser curing is superior to that of conventional light-curing with respect to bond failure and chairside time. However, the incidence of decalcification seems to be similar.
Subject(s)
Dental Bonding/methods , Dental Enamel/radiation effects , Lasers , Orthodontic Brackets , Adhesives , Adolescent , Argon , Child , Female , Humans , Male , Prospective Studies , Statistics, NonparametricABSTRACT
The aim of the present study was to analyse which histological-histomorphometric findings correspond to a radiologically diagnosed open (group I) or closed mid-palatal suture (group II) on occlusal radiographs. For this purpose, 30 radiological regions of interest (rROI) from specimens obtained from 10 subjects ranging in age from 18 to 38 years were evaluated, and compared with the suture morphology, mean sutural width, and degree of suture closure on stained sections (3/rROI). The results showed that whether or not a radiologically visible suture can be classified as 'open' depends predominantly on the main oronasal suture course in relation to the X-ray path, rather than on factors such as suture width and degree of obliteration. The mean sutural width was 231 microns in group I (n = 10 rROI) and 201 mu in group II (n = 20 rROI). The degree of obliteration in relation to the total oronasal suture length was 0.45 in group I and 1.30 per cent in group II. No significant differences were found between the corresponding parameters of the two groups. The term 'suture obliteration' or 'fusion' should be avoided if a suture is radiologically not visible, since in 11 of the 20 rROI in which the suture was not visible no obliteration was recorded morphometrically.
Subject(s)
Cranial Sutures/anatomy & histology , Cranial Sutures/diagnostic imaging , Maxillofacial Development , Palate/anatomy & histology , Palate/diagnostic imaging , Adolescent , Adult , Age Factors , Cephalometry , Female , Humans , Male , RadiographyABSTRACT
Eight banded teeth on two human specimens (9 years, male; 19 years, female) were analyzed regarding the fit of the orthodontic bands and periodontal reactions. Five teeth (three molars, two premolars) were evaluated histologically in the horizontal plane and three (one molar, two premolars) in the sagittal plane using the micro-section method according to Donath. The fit of the bands varied in occluso-apical direction. The mean of marginal gaps was x = 0.23 mm in the occlusal, x = 0.03 mm in the equatorial, and x = 0.28 mm in the cervical area. In the equatorial area the thin cement layer was largely homogeneous, whereas porosities and microfissures were found predominantly in thicker cement layers. 85% of the occlusal and cervical band margins revealed cement defects and/or erosions which were colonized by felted, partially densely compacted microbial plaque. With regard to the periodontal effects, the signs of inflammation in the buccolingual gingival areas were markedly less severe due to the supramarginal position of the band margins. The interdental gingiva of all teeth presented the histological pattern of an established gingival lesion. Leukocyte infiltration and inflammatory exudation in the area of the transseptal fibers were exceptionally pronounced in one lower molar (band exposure time: 6 months). At this site the connective tissue attachment close to the cementoenamel junction was severely damaged on the mesial surface and the pocket epithelium proliferated towards the apex, meaning progression from established gingivitis to an initial periodontal lesion. The histologic findings on these human periodontal tissues confirm that the application and hygiene control of orthodontic bands have to be performed with great care to avoid permanent periodontal destruction.
Subject(s)
Gingiva/pathology , Gingivitis/etiology , Orthodontic Appliances , Periodontitis/etiology , Periodontium/pathology , Adult , Child , Female , Gingivitis/pathology , Humans , Male , Orthodontic Appliances/adverse effects , Periodontitis/pathology , Time FactorsABSTRACT
The aim of this study was to investigate the mesio-marginal findings at tilted molars (TM) by means of histological-histomorphometric evaluation. Eight lateral tooth bone segments with TM (six mandibular, two maxillary) from males aged 20-32 years were compared with those of eight samples with non-tilted molars (NTM) in males aged 18-35 years. In comparison with the NTM samples, the TM revealed a higher amount of supra- and subgingival plaque, a significantly higher total number of inflammatory cells (P < 0.05) and blood vessels (P < 0.05) in the connective tissue adjacent to the junctional epithelium, and a lower density and corono-apical width of gingival fibres. No significant differences (P > 0.05) were found between the mesio-marginal bone level of the TM (mean: 978 microns) and that of the NTM (mean: 1222 microns). In contrast, indications were found that TM may affect the disto-marginal bone level of the mesial tooth.
Subject(s)
Gingivitis/etiology , Tooth Migration/etiology , Tooth Movement Techniques/adverse effects , Adolescent , Adult , Epithelial Attachment/pathology , Gingivitis/pathology , Granulocytes , Humans , Lymphocytes , Male , Molar , Plasma CellsABSTRACT
The aim of this study was to investigate experimentally the effect of long-term orthodontic loading on the activity and location of osteodynamic changes around short titanium screw implants. For this purpose 6 maxillary premolars (1P1, 2P2, 3P3) were extracted from each of 2 foxhounds. After a 16-week healing period, 8 implants (4 per dog) were inserted in the edentulous areas. Simultaneously 2 implants (1 per dog) were positioned in the palatal suture. After an 8-week implant healing period the fixtures in the P1/P2 areas (n = 4) and the palate (n = 2) were loaded (test implants) by means of Sentalloy traction springs (approximately 2 N continuous force). The fixtures in the P2/P3 areas served as controls (n = 4). The osteodynamic changes during the force application period (26 weeks) were recorded with bone labeling fluorochromes. Histological evaluation revealed a tendency towards higher remodeling activity within the peri-implant bone (up to 500 microns from the implant surface) of the loaded compared with the unloaded sample. This higher activity was found on both sides facing the loading direction as well as on the opposite sides. Furthermore, within the bone adjacent to the marginal halves of the implants on the loading direction sides, this higher remodeling activity extended more than 1000 microns from the respective implant surfaces. The results suggest that long-term orthodontic loading of short maxillary implants may increase the remodeling activity within the peri-implant bone.
Subject(s)
Dental Implants , Orthodontic Appliances , Osseointegration , Animals , Bone Screws , Dental Implantation, Endosseous/methods , Dogs , Male , Maxilla/pathology , Microscopy, Fluorescence , Time Factors , Titanium , Wound HealingABSTRACT
A new orthodontic implant anchor system (Orthosystem) has been developed. This 1-piece device made from titanium consists of a screw-type endosseous section (lengths of 4 and 6 mm), a cylindrical transmucosal neck, and an abutment. Clamp caps with slots provide for attachment of square orthodontic wires (transpalatal bars) to the implant. The aim of the present prospective study was to evaluate the anchorage capacity of palatally inserted Orthosystem implants for anchorage reinforcement of posterior teeth. The sample consisted of 9 dental Class II patients (age 15 to 35 years) whose treatment plan included extraction of the maxillary first premolars. Each of the patients received 1 implant inserted into the center of the anterior palate. After a mean unloaded implant healing period of 3 months, transpalatal bars were inserted to connect the posterior teeth to the implant. Retraction of the canines and incisors was accomplished without the use of compliance-dependent headgear or Class II elastics. The degree of anchorage loss as well as the amount of canine and incisor retraction were evaluated by measurements of the casts and lateral cephalograms. The mean anchorage loss was 0.7 mm on the right side and 1.1 mm on the left (P <.05). The right and left canines were retracted 6.6 and 6.4 mm, respectively, and the mean overjet reduction was 6.2 mm. Because clinical assessment and postremoval histologic assessment both revealed stability of the short implant, the small anchorage loss was most likely from the deformation of the transpalatal bars by the orthodontic forces. Nevertheless, the treatment goal was achieved in all patients without the use of compliance-dependent auxiliaries. The clinical experience during and after implant insertion, active orthodontic treatment, retrieval of the implant, and subsequent wound healing are described.
Subject(s)
Dental Implants , Malocclusion, Angle Class II/therapy , Orthodontic Appliance Design/instrumentation , Orthodontic Appliances , Orthodontics, Corrective/instrumentation , Adolescent , Adult , Dental Implantation, Endosseous , Device Removal , Humans , Male , Molar , Osseointegration , Palate/surgery , Patient Compliance , Prospective Studies , Treatment OutcomeABSTRACT
When maximal anchorage is required during orthodontic treatment, additional aids are often needed to support the anchoring teeth. While intra-oral aids may be limited in their anchorage potential, extra-oral anchoring aids are often rejected by the patients. Endosseous implants may therefore be a valuable alternative for stable intra-oral anchorage. However, the possibility of using conventional implants is insufficient, e.g. for treating purely orthodontic patients with full dentition or where extraction sites are to be closed. Therefore, the mid-sagittal area of the palate is an alternative insertion site for the placement of implants for orthodontic anchorage. The limited bone height in this area inspired this comparison between bone thickness in the implantation site as verified by probing during the implantation of Straumann Ortho-system implants, and thickness as measured on the lateral cephalogram. The results suggest that vertical bone support is at least 2 mm higher than apparent on the cephalogram. In none of 12 patients was a perforation to the nasal cavity found. However, in five subjects the implant projected into the nasal cavity on the post-operative cephalogram. These results were supported by the study of the projections of palate and wires in wire-marked skulls where the wires were placed bilaterally on the nasal floor and on the nasal crest. It is therefore concluded that the mid-sagittal area of the palate lends sufficient bony support for the implantation of small implants (4-6 mm endosseous length, diameter 3.3 mm).
Subject(s)
Dental Implantation, Endosseous , Orthodontic Appliances , Palate/surgery , Adolescent , Adult , Cephalometry , Dental Implants , Dental Prosthesis Design , Female , Humans , Male , Nasal Cavity/diagnostic imaging , Orthodontics, Corrective/instrumentation , Palate/diagnostic imaging , RadiographyABSTRACT
Implant-based anchorage in orthodontics is increasingly obtaining significance. In this study, implants were temporarily inserted into the mid-palatal and the mandibular retromolar areas in humans for orthodontic anchorage. Histological analysis of the implant-bone interface was performed following the retrieval of implants which were subjected to prolonged oblique orthodontic loading. The results of the histomorphometric evaluation indicated that all the implants serving for orthodontic anchorage were well integrated into the bone despite the prolonged application of the orthodontic loading. Hence, it may be concluded that small-size, one-part transmucosal implants with a self-tapping thread and an SLA surface seemed to provide adequate anchorage for orthodontic therapy. Furthermore, the successful integration and the subsequent oblique loading of these orthodontic implants provide evidence that continuous forces in the order of magnitude of 2-6 N are compatible with the maintenance of osseointegration.
Subject(s)
Dental Implants , Orthodontic Appliance Design , Osseointegration , Tooth Movement Techniques/instrumentation , Adolescent , Adult , Dental Stress Analysis , Female , Humans , Male , Palate/surgery , Weight-BearingABSTRACT
Control of anchorage is one of the fundamental aspects in orthodontics and dentofacial orthopedics. Osseointegrated implants provide such an anchorage in a reliable fashion, as has been demonstrated in orthodontic use of dental implants inserted for prosthetic reasons. More recently, special implants have been introduced that serve as temporary anchorage in orthodontics. One example is the Straumann Orthosystem (Institut Straumann AG, Waldenburg, Switzerland), which is inserted in the midsagittal area of the palate. Owing to the reduced bone height available in the palate, only short implants should be considered; surface enlargement by texturing and the achievement of good primary stability are prerequisite for success. The use of a palatal implant provides a continuous stable anchorage for patients with compromised periodontal anchorage potential, as well as in cases in which compliance is not dependable or cases with esthetic considerations in which the use of extraoral anchorage aids or Class II elastics may be problematic. Minimal stress on the patient, combined with maximal anchorage, distinguishes this promising new treatment modality for the orthodontist cooperating with an oral surgeon. The treatment concept is well aligned with the emphasized need for integral treatment in dentistry, especially of the adult patient.
Subject(s)
Dental Implantation, Endosseous , Dental Implants , Malocclusion/therapy , Orthodontic Appliance Design , Adolescent , Adult , Female , Humans , Palate/pathology , Palate/surgeryABSTRACT
The aim of this study was to investigate experimentally the effect of long term orthodontic loading on the stability as well as on the peri-implant bone findings of short titanium screw implants (Bonefit, submersion depth 6 mm, phi 4 mm) inserted in regions with reduced vertical bone height. For this purpose, 6 maxillary premolars (1P1, 2P2, 3P3) were extracted from each of 2 foxhounds and reduction of alveolar bone height was performed by osteotomy. After a 16-week healing period, 8 implants (4 per dog) were inserted in the edentulous areas. Simultaneously, 2 implants (1 per dog) were positioned in the palatal suture (one-stage surgery). After an 8-week implant healing period, the fixtures in the P1/P2 areas (n = 4) and the palate (n = 2) were loaded (test implants) by means of transpalatal bars running anteriorly, fixed on the implants in the P1/P2 areas, and Sentalloy traction springs (approximately 2 N continuous force) inserted midsagittally between palatal implants and bars (force application period: 26 weeks). The fixtures in the P2/P3 areas served as controls (n = 4). Clinical measurements and histological evaluation revealed no implant dislocation of the loaded fixtures. These results suggest that short titanium screw implants inserted in the alveolar bone and palatal suture region retain their stability during long-term orthodontic loading, even following a relatively short unloaded implant healing period. Furthermore, it seems that long-term orthodontic loading may induce marginal bone apposition adjacent to the implants.
Subject(s)
Alveolar Process/physiology , Bone Remodeling , Dental Stress Analysis , Implants, Experimental , Orthodontic Appliance Design , Palate/physiology , Animals , Bone Screws , Dental Implantation, Endosseous , Dental Implants , Dogs , Male , Maxilla/physiology , Osseointegration , Surface Properties , Weight-BearingABSTRACT
The aim of this experimental study was to assess the advantages of an early or delayed treatment start after tooth extraction on the basis of hard-tissue findings (density, maturity, osteodynamics) and of soft-tissue responses at the extraction site. Following bilateral extraction of the second incisors, reciprocal space closure was initiated in 3 foxhounds (age: 3.5 years): group 1 (6 teeth) 12 weeks after extraction, group 2 (6 teeth) immediately after extraction. After an 8-week bodily tooth movement period and a 2-month retention period, evaluation was undertaken on the basis of clinical/radiologic and histologic criteria (sequential polychromatic bone marking, light microscopy). Histologic analysis yielded the following findings in group 1 (delayed tooth movement): low bone density at the extraction site with more mature lamellar bone, pronounced horizontal atrophy of the alveolar process with periosteal bone apposition in direction of tooth movement, increased tendency towards gingival invagination. The findings in group 2 were characterized by: higher bone density with less maturity (bundle bone) at the extraction site, broader alveolar process, reduced tendency towards gingival invagination. No qualitative difference between the 2 groups was found with respect to root resorption. The histologic findings therefore indicate that orthodontic retraction into extraction sites should be initiated at an early stage.
Subject(s)
Bone and Bones/anatomy & histology , Orthodontic Appliances , Orthodontic Space Closure , Animals , Bone Remodeling , Dogs , Female , Incisor/surgery , Maxilla , Orthodontic Brackets , Orthodontic Wires , Periodontal Ligament/anatomy & histology , Time Factors , Tooth Extraction , Wound HealingABSTRACT
This paper presents the Orthosystem (Institute Straumann, Waldenburg/ Switzerland), a new endosseous orthodontic implant anchor system for palatal anchorage. The Orthosystem may replace compliance dependent extraoral anchoring aids for orthodontics and makes a bonding of well aligned mandibular dentition and it's use with class II elastics unnecessary. The fixture is designed for a one-stage application. It consists of an implant of pure titanium with a surface-treated, screw-shaped endosseous part of 3.3 mm diameter and lengths of 4 and 6 mm. Above the polished transmucosal neck follows as abutment where transpalatal arches made of rigid orthodontic wires (0.032 x 0.032 inch) are fixed by means of a clamp-cap. 6 patients with an angle class II malocclusion were implanted with the 6 mm fixture in the proximal midsagittal region of the palate during a pilot study. The treatment goal was extraction of the first maxillary premolars with subsequent retraction of the frontal dentition under maximal anchorage of the lateral teeth. For the implantation a simple surgical procedure of 10 min length was required while no further invasive action are needed until explantation. This way the strain on the patients was reduced to a minimum. They are now at varying stages of active treatment and the most advanced case is demonstrated here. The clinical and radiological findings after 12 months of treatment comprising 3 months of healing revealed no implant mobility or dislocation, favourable periimplant soft tissue conditions, and no marked mesial movement of the implant supported teeth. The frontal dentition was retracted by 8 mm with space closure occurring in a relatively short treatment period.