Establishment of experimental models to evaluate the effectiveness of dental trauma splints.

The purpose was to describe a novel simple experimental model of injured teeth for developing dental trauma splints (DTS), and to test various splints by combining use of this model and the Periotest® device. Rubber O-rings and spring washers were used to simulate and modify injured tooth mobility. Splinting effects were assessed among three kinds of DTS, including a composite splint and two wire-composite splints (1: rectangular orthodontic wire 0.533×0.635 mm, 2: cobalt-chromium alloy wire Φ0.9 mm). The Periotest values were measured three times for each tooth before and after splint insertion. The splinting effect was defined as the change in tooth mobility. Splinting effects significantly increased in the order wire-composite splint 1

Post-treatment changes in permanent retention.

OBJECTIVES: While permanent retention is today the method of choice to stabilize orthodontic treatment outcomes, recent studies have increasingly reported posttreatment changes in tooth position during permanent retention. We conducted this study to analyze changes in the anterior mandible, whether the changes follow an underlying movement pattern, and, aiming for a preventive strategy, whether any risk factors could be identified comparing findings with the pretreatment situations. METHODS: We included 30 patients who had worn fixed Twistflex retainers (UK 3-3) extending from canine to canine in the mandible. Casts reflecting the intraoral situations before orthodontic treatment (T0), directly after completion of active therapy (T1), and 6 months later (T2) were scanned and superimposed using Imageware Surfacer software. Posttreatment changes (T2-T1) of tooth position within the retainer block were analyzed on 3D virtual models and were compared to pretreatment (T0) and treatment-related (T1-T0) findings to identify potential risk factors. RESULTS: Almost all analyzed patients revealed three-dimensional changes in tooth position within the retainer block. Comparing these movements, we repeatedly found rotated retainer blocks in labio-oral direction, while the center of rotation was located at the first incisors. This pattern was associated with intercanine expansion and excessive overjet correction during orthodontic treatment. The canines underwent the most pronounced (rotational and translational) movements. CONCLUSIONS: In general permanent lingual retainers are safe but in special clinical cases retainers can induce undesired tooth movement. Risk factors seem to be intercanine expansion and excessive overjet correction during orthodontic treatment. In specific cases an additional retention device might be needed.

Stiffness characteristics of splints for fixation of traumatized teeth.

BACKGROUND/AIM: Traumatic dental injuries (TDI) are treated by repositioning and splinting. Ideally, injured teeth should possess some mobility for optimal periodontal and pulp healing. Splints should be easy to apply in emergencies, affordable, and esthetically acceptable. The aims were to compare some clinically used splints with regard to stiffness (measured in Nm(-1)), esthetics, cost, and ease of application. MATERIALS AND METHODS: Six splints were applied to dental models using an acid-etched bonding technique. One central incisor was adjusted to give 1 mm of horizontal movement at the incisal edge. The mobilized tooth was then connected to adjacent teeth with either twistflex wire (TF), titanium trauma splint (TTS), single (SFG) and double fiberglass (DFG), nylon (fishing) line (FL), or power chain (PC). A horizontal force was then gradually applied to the incisor in a standardized manner with a spherical probe (1.65 mm radius), monitoring force with a 50N load cell and displacement with a linear variable differential transformer (LVDT). Signals were amplified, converted digitally (14-bit analog-to-digital converter), and displayed in real time to show the splint stiffness. Splints were also ranked with regard to esthetics, application time needed, and ease of application cost. RESULTS: FL and PC were the least stiff, averaging 5.7 and 6.3 Nm(-1), respectively. TTS averaged 6.9 Nm(-1), while SFG and TF averaged 18.5 and 18.4 Nm(-1), respectively. DFG was the stiffest, averaging 24.3 Nm(-1). PC and SFG were the fastest to apply. FL showed the best esthetic score, followed by TTS and PC. TTS was the most expensive splint, while FL, PC, SFG, DFG, and TF showed similar costs. CONCLUSIONS: Of these TDI splints, DFG should be avoided for flexible splinting because it is too stiff. PC may be an interesting novel alternative, affording sufficient mobility due to its low stiffness.

Recombinant osteoprotegerin effects during orthodontic movement in a rat model.

BACKGROUND AND OBJECTIVES: Anchorage is one of the most challenging sides in orthodontics. The use of biological modulators that inhibit osteoclasts could be a solution to address these problems and provide new adjunctive approaches. The aim of this study was to assess the effectiveness of recombinant osteoprotegerin fusion protein (OPG-Fc) in orthodontic anchorage. MATERIALS AND METHODS: Two groups of male Sprague-Dawley rats were utilized. The animals in the experimental group received twice-weekly injections with high dose of OPG-Fc (5.0mg/kg) in mesial and distal mucosa of the first molars, and those in the control group received no drugs. Right first maxillary molars were mesialized using a calibrated nickel-titanium spring connected to an anterior mini-screw. Tooth movement was measured by two blinded observers using scanned and magnified stone casts. Receptor activator of nuclear factor κB (RANK), run-related transcription factor 2 (Runx2), type I collagen, vimentin, matrix metalloproteinases 2 and 9, S100 protein and the putative mechanoproteins acid-sensing ion channel (ASIC2) and transient receptor potential vainilloid 4 (TRPV4) were evaluated using immunohistochemistry. RESULTS: OPG-Fc group showed an important decreased in mesial molar movement with only 52%, 31%, and 22% of the total mesial molar movement compared with control group at Days 7, 14, and 21, respectively (P < 0.001). RANK ligand and Runx2 positive cells were severely reduced after OPG-Fc treatment. Periodontal ligament architecture, cell arrangement, and immunohistochemical patter for vimentin, type I collagen and the mechanoproteins TRPV4 and ASIC2 were altered by tooth movement and all these parameters altered by the applied treatment. CONCLUSIONS: OPG-Fc effectively inhibits osteoclastogenesis resulting in improved bone quantity and orthodontic anchorage. Based on present results, OPG-Fc could have clinical utility in preventing undesired tooth movements.

Experimental evidence of pharmacological management of anchorage in Orthodontics: A systematic review.

INTRODUCTION: Orthodontic anchorage is one of the most challenging aspects of Orthodontics. Preventing undesired movement of teeth could result in safer and less complicated orthodontic treatment. Recently, several reviews have been published about the effects of different molecules on bone physiology and the clinical side effects in Orthodontics. However, the effects of local application of these substances on the rate of orthodontic tooth movement have not been assessed. OBJECTIVES: The aim of this research was to analyze the scientific evidence published in the literature about the effects of different molecules on orthodontic anchorage. METHODS: The literature was systematically reviewed using PubMed/Medline, Scopus and Cochrane databases from 2000 up to July 31st, 2014. Articles were independently selected by two different researchers based on previously established inclusion and exclusion criteria, with a concordance Kappa index of 0.86. The methodological quality of the reviewed papers was performed. RESULTS: Search strategy identified 270 articles. Twenty-five of them were selected after application of inclusion/exclusion criteria, and only 11 qualified for final analysis. Molecules involved in orthodontic anchorage were divided into three main groups: osteoprotegerin (OPG), bisphosphonates (BPs) and other molecules (OMs). CONCLUSIONS: Different drugs are able to alter the bone remodeling cycle, influencing osteoclast function and, therefore, tooth movement. Thus, they could be used in order to provide maximal anchorage while preventing undesired movements. OPG was found the most effective molecule in blocking the action of osteoclasts, thereby reducing undesired movements.

[THE INFLUENCE OF MODERN ORTHOPEDIC CONSTRUCTIONS ON THE CONDITION OF PERIODONTAL TISSUES OF PATIENTS WITH GENERALIZED PERIODONTITIS].

Patients with generalized periodontitis studied the effect of the partial removable denture made from acrylic met and thermoplastic materials on the state of periodontal tissues. The results of clin- ical studies have shown a significant improvement in oral hygiene, positive change in activity indi- cators current generalized periodontitis: patients for whom orthopedic constructions are made of thermoplastic mass, reduce the depth of periodontl pockets, tooth mobility, bleeding and inflamma- tion of the interdental, papillae and the gingival margin.

Emergencies in orthodontics. Part 1: Management of general orthodontic problems as well as common problems with fixed appliances.

Fixed appliance treatment is a popular treatment modality with a burgeoning increase in the numbers of children and adults realizing the benefits that can be gained. Appliance breakage is an unavoidable nuisance which is at best inconvenient, and at worst may result in significant pain or discomfort for the patient. General dental practitioners (GDPs) should have the practical knowledge of how to provide timely and appropriate orthodontic 'emergency treatment'. This will significantly reduce the sometimes considerable inconvenience and discomfort for both the patient and his/her parents, and the inevitable frustration for the clinician providing ongoing care. This first paper will deal with general orthodontic problems that commonly present, as well as some issues specific to fixed appliances. The second paper will deal with the other orthodontic appliances that may be encountered by GDPs in their daily practice. Clinical Relevance: Appropriate handling of an orthodontic 'emergency' by the general practitioner will, on many occasions, provide immediate relief of pain and distress for the patient. This will in turn allow treatment to continue moving in the right direction, thus allowing more efficient and effective use of valuable resources.

Influence of different flask systems on tooth displacement and framework misfit in mandibular fixed implant-supported complete dentures.

PURPOSE: To evaluate the influence of different metallic flask systems for acrylic resin denture processing on tooth displacement and framework misfit of mandibular fixed implant-supported complete dentures. METHODS: Standard mandibular implant-supported complete dentures in five implants were waxed and randomly assigned to three groups: G1 - conventional flask, G2 - double flask, and G3 - occlusion flask. Framework misfit in all the implants and the linear distances between teeth (I-I - incisor-to-incisor; P-P - premolar-to-premolar; M-M - molar-to-molar; RI-RM - right-incisor-to-right-molar; and LI-LM - left-incisor-to-left-molar) were measured before and after denture processing using an optical microscope. Dentures were processed by hot water curing cycle (9h/74°C). Collected data were analyzed by paired Student's t-test and one-way ANOVA (α=0.05). RESULTS: All the measured distances presented changes in tooth displacement after denture processing. However, the M-M distance for G1 (p=0.003) and the P-P (p=0.042) and LI-LM (p=0.044) distances for G3 showed statistically significant differences. Differences between the flask systems were not statistically significant. Statistically significant differences in the framework misfit due to denture processing were found for all the implants and groups, with the exception of right median implant for G2 and right distal implant for G3. A comparison of the flask systems found statistically significant differences in which G1 presented an increase in the misfit values and G2 and G3 a decrease. CONCLUSIONS: Different flask systems did not cause significant changes in tooth displacement. Frameworks misfit values were influenced by the different flask systems. The conventional flask presented an increase in the framework misfit, while the experimental flasks showed a decrease.

Twelve-year results of a direct-bonded partial prosthesis in a patient with advanced periodontitis: a clinical report.

Prosthodontic treatment for patients with advanced periodontitis is a therapeutic challenge. A minimally invasive technique is preferred to preserve the remaining mobile abutment teeth. This report describes the initial clinical treatment and 12-year follow-up of a direct-bonded prosthesis reinforced with a cast metal framework, used as a conservative treatment option to replace periodontally involved maxillary lateral incisors.

Survival of molar teeth after resective periodontal therapy--a retrospective study.

AIM: To study outcomes of molar teeth after resective therapy performed with the intention to prolong the lifespan of teeth having one or more unsaveable roots, and without which tooth extraction would be inevitable. MATERIAL AND METHODS: Clinical records of 149 subjects who had undergone resective therapy were retrieved. Demography and dental history were recorded, and a recall examination was undertaken. Cox regression models were performed. RESULTS: Of the 149 resective therapies, 132 (88.6%) were performed for periodontal reasons. Eighty-nine (59.7%) teeth subjected to resective therapies had been extracted by the time of recall (mean 10 years post-resection). The median survival period was 74 months. Factors significantly associated with shorter survival duration of teeth subjected to resective therapy were: age at resective therapy; pre-operative radiographic bone height of the remaining root(s) <50%; pre-treatment mobility II or above and not being splinted to neighbouring teeth nor incorporated as a bridge abutment. CONCLUSION: There was increased risk of tooth loss with increasing age at resection, grade II mobility or above, and reduced pre-operative radiographic bone heights around roots to remain. Splinting of a resected tooth to neighbouring teeth appeared to confer a protective effect towards its survival.

[The impact of bisphosphonates on orthodontic treatment]. / De invloed van bisfosfonaten op een orthodontische behandeling.

Bisphosphonates are used in the treatment of various diseases which are associated with a disturbance of the balance between bone apposition and degradation. The most important complication of bisphosphonate use is osteonecrosis of the jaw. Certain components of an orthodontic treatment plan, such as the extraction of 1 or more teeth, are important risk factors in developing this complication. In addition to the desired effects on the bone metabolism, bisphosphonates may delay tooth eruption and inhibit or block orthodontic tooth movement. Nevertheless, case studies suggest that orthodontic treatment is possible despite the use of bisphosphonates. However, it is recommended to avoid orthodontic treatment unless this is strictly indicated.

In vivo evaluation of lesion sterilization and tissue repair in primary teeth pulp therapy using two antibiotic drug combinations.

AIM: The purpose of this study is to evaluate and compare the clinical and radiographic effectiveness of Ciprofloxacin, Minocycline, Metronidazole combination with Ciprofloxacin, Minocycline and Tinidazole combination when used for Lesion Sterilization and Tissue Repair in primary teeth. METHOD: 25 healthy children, visiting Dept. of Pediatric & Preventive Dentistry, D.A.P.M.R.V. Dental College, Bangalore, India, aged between 6-9 years who were having 30 infected primary teeth are selected and divided into 2 groups. In Group A, a mixture of 3mix-MP Ciprofloxacin, Metronidazole and Minocycline was placed on the floor of the pulp chamber covering the root canal orifices. In Group B a mixture of Ciprofloxacin, Tinidazole and Minocycline was placed as a layer on the floor of the pulp chamber. The procedure was completed in a single visit. Post operative clinical evaluation was done after 1,6,12 and 24 months. Postoperative radiographic evaluation was done at 6, 12 and 24 months. RESULTS: No statistically significant difference is observed between both the groups and a combination of Ciprofloxacin, Minocycline and Tinidazole antibacterial drugs can be used on teeth pulpally involved with physiologic root resorption. CONCLUSION: After a 24 Month follow up, we can conclude that primary teeth with the periradicular lesions, can be conserved by using combination of Ciprofloxacin, Minocycline and Tinidazole antibacterial drugs.

The effect of splint material and thickness on tooth mobility after extraction and replantation using a human cadaveric model.

Although current guidelines for the treatment of traumatic injuries recommend the use of 'flexible' splints, the precise definition of what is considered flexible versus rigid has not been rigorously defined, leaving the clinician with a wide range of options for this critical factor. The purpose of this study was to quantify and compare the effect of eight different splints on tooth mobility after extraction and replantation using a human cadaveric model. Following strict selection criteria including complete root maturation, lack of periodontal disease, normal bone levels, and crown integrity, a maxillary central incisor was atraumatically extracted and splinted with eight different splints. The experimental splints included a 20-pound test (9.072-kilogram test) [corrected] monofilament nylon-composite splint and six wire-composite splints made of wires of 0.012' (0.3 mm), 0.016' (0.4 mm), or 0.020' (0.5 mm) diameter stainless steel (SS) or nickel titanium (NT). A direct composite splint represented the most rigid type of splint. These eight splints were applied five times each, and tooth mobility was measured before and after each splint was applied. The average splint effect, defined as the difference between the presplint and the postsplint measurements quantified using the Periotest, was calculated for each splint and compared. No significant differences were found between the nylon-composite and the wire-composite splints. There was significantly less tooth mobility with the direct composite splint compared to all other splints. In conclusion, the results of this study suggest that nylon and SS or NT wires up to 0.016' diameter are significantly more flexible than direct composite splints and thus may be better suited for the splinting and management of traumatized teeth.

A minimally invasive approach to restore function and esthetics in periodontally involved teeth.

The objective of dental treatment is the elimination of the etiologic factors, the rehabilitation of function and esthetics, and, when possible, the maintenance of vitality and structure of the natural dentition. After the loss of the periodontal support, as a consequence of periodontal disease, it may be necessary to splint the residual teeth in order to improve their stability, and sometimes it is also necessary to modify the morphology to optimize the final esthetic outcome. In many periodontally treated teeth, prosthodontic treatment on the residual dentition will be required with an important loss of tooth structure as an unavoidable consequence. This procedure frequently requires endodontic treatment of the residual abutments in order to obtain the necessary space for replacement materials. Similar objectives could however be achieved through an alternative therapy where the esthetic remodeling of the teeth and the closure of the interproximal spaces is obtained with composite resin materials. The objective of this article is to present an alternative protocol to optimize the functional and esthetic result of periodontally treated cases, where the most frequent complication is the increased length of the clinical crown. This is obtained by utilizing a different conservative approach, which has as its main objective the stabilization of the residual teeth, the maintenance of their vitality, and the achievement of the best esthetic result possible.

Eighteen-month clinical and radiographic evaluation of two root canal-filling materials in primary teeth with pulp necrosis secondary to trauma.

AIM: This study compared clinically and radiographically the use of zinc oxide and eugenol cement (ZOE) and a commercial calcium hydroxide and polyethylene glycol-based paste (Calen(®) ) thickened with zinc oxide as root canal-filling materials for primary teeth with pulp necrosis secondary to trauma within 18months of follow up. MATERIAL AND METHODS: Eligible patients of both genders aged 2years and 6months to 5years and 10months who had been referred for dental treatment at a pediatric dental trauma service and presented at least one anterior primary tooth (central and/or lateral incisor) with pulp necrosis secondary to traumatic injury were selected. Twenty-six children (n=31 teeth) with mean age of 3.4years met the inclusion criteria and were enrolled after parental written consent. The root canals were instrumented and filled with either ZOE (group I; n=15 teeth) or Calen(®) paste [composition: 2.5g calcium hydroxide, 0.5g zinc oxide, 0.05g colophony, and 1.75ml polyethylene glycol 400 (vehicle)] thickened with zinc oxide (Calen(®) /ZO; group II; n=16 teeth). ZO was added to the Calen(®) paste for slowing paste resorption, which should ideally occur simultaneously with the physiologic resorption of primary tooth roots. Clinical success after 18months of follow up was considered as absence of pain, tooth mobility or fistula, and radiographic success as the partial or total remission of apical periodontitis, absence of pathological root resorption or presence of new bone formation. RESULTS: Eighteen months after treatment, the teeth obturated with ZOE and Calen(®) /ZO presented statistically similar (Fisher's exact test; P >0.05) success rates of 93.3% and 87.5%, respectively. CONCLUSION: Our results showed the clinical and radiographic outcomes for Calen(®) /ZO to be equal to those for ZOE after 18months, suggesting that both materials can be indicated for obturating primary teeth with pulp necrosis after trauma.

Effect of atorvastatin on chronic periodontitis: a randomized pilot study.

AIM: We studied the effect of atorvastatin (ATV) treatment on bone loss prevention in subjects with chronic periodontitis. MATERIAL AND METHODS: In this controlled double-blind study, 38 subjects with chronic periodontitis were randomized into two groups, paired by age to receive ATV (20 mg) or placebo daily for 3 months. Periodontal mechanical treatment was carried out in both groups at baseline. Clinical and radiographic parameters and bone turnover markers were assessed at baseline and at 3 months. RESULTS: Periodontal disease conditions improved in both groups. After comparing the figures of change, significant improvements were observed in cholesterol levels (Δ=-58.5 ± 37.6 versusΔ=5.4 ± 41.2 mg/dl, p<0.0002), low-density lipoprotein levels (Δ=-48.1 ± 31.7 versusΔ=1.9 ± 42.8 mg/dl, p<0.002), dental mobility (Δ=-0.17 ± 0.11 versusΔ=-0.06 ± 0.11%, p<0.04), and the distance from the crestal alveolar bone to the cemento-enamel junction (Δ=-0.75 ± 0.7 versusΔ=0.09 ± 0.4 mm, p<0.0006) in the ATV group. CONCLUSIONS: The results suggest that ATV might have beneficial effects on bone alveolar loss and tooth mobility in subjects with periodontal disease.

Evaluation of stress induced by implant type, number of splinted teeth, and variations in periodontal support in tooth-implant-supported fixed partial dentures: a non-linear finite element analysis.

BACKGROUND: This study investigated the biomechanical interactions in tooth-implant-supported fixed partial dentures (FPDs) with variations in periodontal support, implant system, number of splinted teeth, and load type using the non-linear finite element (FE) approach. METHODS: The section contours of the alveolar bone, abutment teeth, and prosthesis were acquired using computed tomography (CT) and micro-CT to construct the FE models with normal periodontal support (NPS) and compromised periodontal support (CPS) containing one- and two-piece implants splinted to the first and second premolars. Realistic interface conditions within the implant system were simulated using frictional contact elements. The main effects for each level of investigated factors in terms of stress values and dissimilar mobility of natural teeth and the implant were computed for all models. RESULTS: Analytic results indicated that the load condition was the predominant factor affecting stress developed in the implant, bone, and prosthesis. Additionally, the oblique occlusal forces increased the stress values relative to that of axial analogs. A splinted system with a two-piece implant increased stress on the bone and decreased stress on the prosthesis compared to that of the one-piece implant. The splinted system with a CPS only slightly increased implant stress on the bone compared to that of the splint system with NPS. Splinting an additional tooth did not significantly impact stress values for the tooth-implant-supported FPD. CONCLUSIONS: A one-piece structure implant may be better than that of a two-piece structure implant in decreasing bone stress when a natural tooth is planned to connect with an implant. The factors of periodontal support and number of splinted teeth only slightly influenced stress in tooth-implant-supported FPDs.

Rigidity of commonly used dental trauma splints.

BACKGROUND/AIMS: The stability of immobilization devices varies from flexible to rigid, depending on the trauma. We evaluated the rigidity of various commonly used splints in vitro MATERIAL AND METHODS: An acrylic resin model was used. The central incisors simulated injured teeth, with increased vertical and horizontal mobility. The lateral incisors and canines stimulated uninjured teeth. Tooth mobility was measured with the Periotest device. Vertical and horizontal measurements were made before and after splinting, and the difference between values was defined as the splint effect. We evaluated 4 composite splints, 3 wire-composite splints, a titanium trauma splint, a titanium ring splint, a bracket splint, and 2 Schuchardt splints RESULTS: For all injured teeth and all splints, there was a significant splint effect for the vertical and horizontal dimensions (P < 0.05). For injured teeth, the composite splints produced the largest changes in vertical tooth mobility; wire-composite splints 1 and 2, using orthodontic wires, produced the smallest vertical splint effects. For uninjured teeth, the Schuchardt 1 splint and the bracket splint produced the largest splint effects; wire-composite splints 1 and 2 produced only a slight change in tooth mobility. Composite splints 2 and 3 produced the largest horizontal splint effects for injured teeth, and the 4 composite splints produced the largest horizontal splint effects for uninjured teeth. The most horizontally flexible splints were the titanium trauma splint and wire-composite splints 1 and 2. CONCLUSIONS: According to the current guidelines and within the limits of an in vitro study, it can be stated that flexible or semirigid splints such as the titanium trauma splint and wire-composite splints 1 and 2 are appropriate for splinting teeth with dislocation injuries and root fractures, whereas rigid splints such as wire-composite splint 3 and the titanium ring splint can be used to treat alveolar process fractures.

Provisional prosthetic management of mobile teeth in conjunction with a removable partial denture using orthodontic wire.

Precision attachment-retained removable partial dentures eliminate the use of visible clasps and improve the esthetic appearance of the smile; however, terminal abutment teeth may be subject to unfavorable stresses under function when misused. A provisional prosthetic management technique that incorporates an orthodontic wire to assist cross-arch support and stability of the periodontally weakened abutment teeth is described. This technique is simple, reversible, does not alter the esthetic appearance of the smile, and controls the mobility of the abutment teeth until a definitive treatment plan is established.