Influence of implant macro-designs on primary and secondary implant stability / Influencia de los macrodiseños de implantes en la estabilidad primaria y secundaria del implante

Introduction: Tapered implants have shown that thanks to their macro design they are capable of expanding the surgical bed performed by the surgeon, which in clinical practice gives a feeling of greater stability, however it is highly subjective and dependent on the operator. Aim: To analyze the influence of the implant macro design in the primary and secondary stability by means of analysis of resonance frequency and force of insertion. Methods: 38 Screw Type and Tapered Type implants were placed in 18 patients in the Bucomaxillofacial Implantology program of the University of Chile during 2006 and 2007 in type II or III bone jaws according to Leckholm and Zarb. Implant stability, implant stability coefficient (ISQ), was measured through Ostell® mentor at the time of installation (ISQ1) and then at connection (ISQ2) and the Insertion Torque through the Osseoset® machine: 17 Screw Type implants with an approximate average contact area of 237 mm2 (3.75/15 mm; 3.75/13 mm) and 17 Tapered Type implants with an approximate average contact area of 226 mm2 (4.3/13 mm; 4.3/16 mm). Results: The averages of ISQ1 and ISQ2 and Insertion Torque respectively for implants with an approximate contact area of 237 mm2 were 71.3 ISQ1, 66.6 ISQ2 and 44.52 Ncm; for 226 mm2 implants it was 75 ISQ1, 72.5 ISQ2 and 48.82 Ncm. Conclusion: Implants with an average contact area of approximately 226 mm2 (Tapered Type) present significantly higher primary and secondary stability than those with an average contact area of approximately 237 mm2 (Screw Type). (Average ISQ1: p = 0.0473; Insertion Torque: p = 0.0031 and Average ISQ2: p = 0.0039)(AU)

Introducción: Los implantes Cónicos han demostrado que gracias a su macro diseño son capaces de expandir el lecho quirúrgico realizado por el cirujano, lo que en la práctica clínica da una sensación de mayor estabilidad, sin embargo, ella es altamente subjetiva y dependiente del operador. Objetivo: Analizar la influencia del diseño del implante en la estabilidad primaria y secundaria mediante análisis de frecuencia de resonancia y Torque de Inserción. Métodos: 38 implantes Tipo Tornillo y Tipo Cónico fueron colocados en 18 pacientes en el programa de Implantología Bucomáxilofacial de la Universidad de Chile durante el año 2006 y 2007 en maxilares de hueso tipo II o III según Leckholm y Zarb. Se midió la estabilidad implantaria, coeficiente de estabilidad del implante (ISQ), a través de Ostell® mentor al momento de la instalación (ISQ1) y luego en la conexión (ISQ2) y el Torque de Inserción a través de el motor Osseoset®: 17 implantes Tipo Tornillo de área de contacto promedio aproximada de 237 mm2 (3.75/15 mm; 3.75/13 mm) y 17 implantes Tipo Cónico de área de contacto promedio aproximada de 226 mm2 (4.3/13 mm; 4.3/16 mm). Resultados: Los promedios de ISQ1 e ISQ2 y Torque de Inserción respectivamente para implantes de área contacto aproximada de 237 mm2 fue de 71,3 ISQ1, 66,6 ISQ2 y 44,52 Ncm; para implantes de 226 mm2 fue de 75 ISQ1, 72,5 ISQ2 y 48,82 Ncm. Conclusión: Los implantes de área contacto promedio aproximada de 226 mm2 (Tipo Cónicos) presentan estabilidad primaria y secundaria significativamente mayor a los de área contacto promedio aproximada de 237 mm2 (Tipo Tornillo). (Promedio ISQ1: p = 0.0473; Torque de Inserción: p = 0.0031 y Promedio ISQ2: p = 0.0039)(AU)

Multidisciplinary treatment with a customized lingual appliance for an adult patient with severe Class III malocclusion and multiple missing teeth.

A 24-year-old man presented with a severe skeletal class III malocclusion, associated with an anterior and posterior crossbite in the left side, upper and lower lip eversion, skeletal asymmetry, midline discrepancy, diastemas in the maxillary and mandibular dental arches, and agenesis of maxillary lateral incisors and canines with retained deciduous teeth. Treatment was performed with the use of the Win Lingual System. When the 0.016 × 0.022-inch NiTi archiwire was applied, the deciduous teeth were extracted and replaced with temporary crowns connected to the appliance. After the aligning, leveling, and diastema closure phases, a modified Le Fort II osteotomy, a mandibular setback with a bilateral sagittal split osteotomy and a genioplasty were performed. Implants were placed in the canine site through a flapless guided surgery, and cantilevered temporary bridges were delivered. Final prosthetic rehabilitation included veneers for the central incisors and zirconia-ceramic cantilevered bridges for the canine and lateral incisors. After 36 months of active treatment, the patient showed an Angle Class I molar and canine relationship and an ideal overbite and overjet. His profile had improved, lips were competent, and gingival levels were acceptable. The lateral radiograph and cephalometric analysis showed a good balance of the skeletal pattern, a good profile of the soft tissue, and proper inclinations of the maxillary and mandibular incisors in relation to maxilla and mandible. After 2 years of follow-up, the patient had a pleasant smile and no relapse, or joint or muscular pain.

Obstructive sleep apnoea in a patient with chronic lymphocytic leukaemia.

A 69-year-old Caucasian woman presented with chronic lymphocytic leukaemia (CLL; stage 1-Rai System), significant oropharyngeal lymphoid enlargement, snoring and fatigue. Overnight polysomnography revealed moderately severe obstructive sleep apnoea (OSA), which was managed successfully with oral appliance therapy with resolution of snoring and daytime fatigue. Structural abnormalities of the upper airways are known to cause OSA. Airway narrowing can result from bony structural abnormalities, nasopharyngeal growth, soft tissue redundancy, macroglossia, malignant and benign growth of the upper aero-digestive tract, and adenotonsilar enlargement. Clinicians should be encouraged to consider a diagnosis of OSA in patients with CLL when they present with symptoms of worsening fatigue.

Finite element analysis of slot wall deformation in stainless steel and titanium orthodontic brackets during simulated palatal root torque.

INTRODUCTION: Torque applied on anterior teeth is vital for root positioning and stability. The aim of this study was to evaluate the detailed slot wall deformation in stainless steel (SS) and titanium (Ti) edgewise brackets during palatal root torque using finite element analysis. METHODS: A finite element model was developed from a maxillary central incisor SS bracket (0.022 in). The generated torque values from an SS rectangular archwire (0.019 × 0.025 in) while twisting from 5° to 40° were obtained experimentally by a spine tester, and the calculated torque force was applied in the bracket slot. The deformations of the slot walls in both SS and Ti brackets were measured at various locations. RESULTS: There were gradual increases in the deformations of both bracket slot walls from the bottom to top locations. In the SS bracket slot for the 40° twist, the deformations were 9.28, 36.8, and 44.8 µm in the bottom, middle, and top slot wall locations, respectively. Similarly, in the Ti bracket slot for the 40° twist, the deformations were 39.2, 62.4, and 76.2 µm in the bottom, middle, and top slot wall locations, respectively. The elastic limits were reached at 28° for SS and at 37° for Ti. CONCLUSIONS: Both SS and Ti bracket slots underwent deformation during torque application. There are variations in the deformations at different locations in the slot walls and between the materials.

Vacuum-formed retainers: an overview.

The need for long-term retention following orthodontic treatment is now considered essential to prevent post-orthodontic treatment relapse. The vacuum-formed retainer (VFR) has gained popularity in recent times. This paper describes briefly the characteristics of VFRs and summarizes the evidence in relation to their effectiveness. Clinical Relevance: VFRs are now widely used after orthodontic treatment and it is important that clinicians adopt an evidenced-based approach to their use.

Molar uprighting by a nickel-titanium spring based on a setup model.

Molar uprighting is an important adjunctive treatment in orthodontics: repositioning the tilted molar eliminates the potentially pathologic condition and simplifies the ultimate restorative procedure. Although various methods for molar uprighting have been applied successfully, they still have some limitations and disadvantages in tooth movement. This article reports on a new clinical technique for molar uprighting with nickel-titanium springs based on a setup model. Two patients treated with this system are shown.

Efficiency, behavior, and clinical properties of superelastic NiTi versus multistranded stainless steel wires: a prospective clinical trial.

OBJECTIVE: To investigate efficiency, behavior, and properties of superelastic NiTi vs multistranded stainless steel wires in Begg and preadjusted edgewise appliance (PEA) under moderate to severe crowding conditions. MATERIAL AND METHODS: Ninety-six participants (48 male, 48 female), aged 12-18 years old (mean age  =  15.2 ± 1.95), with moderate (≤ 6 mm; mean  =  5.3 ± 0.48) to severe (> 6 mm; mean  =  7.9 ± 0.66) initial crowding were distributed into four groups: superelastic NiTi PEA (n  =  24), superelastic NiTi Begg (n  =  24), multistranded (coaxial) stainless steel PEA (n  =  25), and multistranded (coaxial) stainless steel Begg (n = 23). In this study, 0.16-inch superelastic (austenitic active) NiTi and 0.175-inch multistranded (six stranded, coaxial) stainless steel wires were used in a 0.022-inch slot (Roth prescription) PEA and Begg appliance with a follow-up of six weeks. RESULTS: Analysis of variance revealed no significant difference in reduction of crowding between superelastic NiTi PEA and multistranded (coaxial) stainless steel PEA groups, but reduction in crowding was significantly greater in the superelastic NiTi Begg group compared with the multistranded (coaxial) stainless steel Begg group with F (3, 44)  =  8.896, P < .001, and effect size (ω) 0.57 in moderate crowding and F (3, 44)  =  122.341, P < .001, and effect size (ω) 0.93 in severe crowding. Linear regression demonstrated significant (P < .05) positive correlation between amount of initial crowding and reduction in crowding in all groups except the multistranded (coaxial) stainless steel Begg group, wherein a negative correlation did exist. CONCLUSION: Superelastic NiTi performed significantly better than multistranded (coaxial) stainless steel wire in the Begg appliance. However, in PEA, there was no significant difference.

Comparative evaluation of dento-alveolar distraction and periodontal distraction assisted rapid retraction of the maxillary canine: a pilot study.

Distraction osteogenesis is a biological process of new bone formation between the surfaces of the bone segments that are gradually separated by incremental traction. A recent innovative use of distraction osteogenesis in orthodontic tooth movement is to move individual tooth segments rapidly thus reducing orthodontic treatment time. Six patients, comprising two groups, were compared using two different surgical techniques: dento-alveolar distraction and periodontal distraction to bring about rapid canine retraction using an indigenously designed intra-oral distractor. The aim was to assess and evaluate the best approach to reduce the overall orthodontic treatment time by means of distraction osteogenesis. The patients were assessed at regular intervals with intra-oral periapical radiographs and lateral cephalograms for gauging the time required for retraction, canine tipping, anchorage loss and external root resorption. Dento-alveolar distraction was superior to periodontal distraction in all areas of assessment.

Temporary skeletal anchorage devices for orthodontics.

This article discusses the recent advances and basic concepts of skeletal anchorage devices of various types and reviews the current literature on their use. Temporary skeletal anchorage devices allow orthodontic movements that were previously thought to be difficult if not impossible. Much like the concepts introduced during the beginnings of orthognathic dentofacial teams, treatment that uses skeletal anchorage requires interdisciplinary collaboration and planning with regular interaction, continuing education, and a regular review of the latest relevant literature.

Comparación del esfuerzo a la tracción de brackets arenados mediante óxido de aluminio nuevo y reciclado con y sin ultrasonido estudio in vitro / Comparison of tensile stress in brackets sandblasted by aluminum oxide and recycled again and without ultrasound in vitro study

El fracaso en la adhesión de brackets es algo que ocurre frecuentemente y requiere el uso de un aditamento nuevo. Con la introducción del arenado, se pretende reutilizarlos sometiéndolos a un proceso de limpieza mejorando así la adhesión. El objetivo del estudio es comparar el esfuerzo a la tracción de brackets arenados mediante óxido de aluminio nuevo y reciclado con y sin ultrasonido. Se incluyeron 80 primeros y segundos premolares humanos dividido aleatoriamente en 5 grupos de 16 premolares: (C) brackets nuevos, (AN) brackets arenados con óxido de aluminio nuevo, (AN+U) arenado con óxido de aluminio nuevo más ultrasonido, (AR) arenado reciclado y (AR+U) arenado reciclado más ultrasonido. La adhesión se realizó con el mismo tipo de brackets y resina; el esfuerzo a la tracción se realizó mediante máquina Instrom. Se evidenció que los brackets AN aumentaron el esfuerzo a la tracción y esta se incrementó con el baño ultrasónico. Los brackets AR disminuyeron su esfuerzo a la tracción considerablemente, pero con ultrasonido mostraron valores cercanos al grupo C. La prueba t-student demostró que los grupos C vs. AN, AN vs. AN+U, y C vs. AR+U no tuvieron diferencias significativas. En cambio los grupos C vs. AN+U, C vs. AR, AN vs. AR, AN vs. AR+U, AN+U vs. AR+U mostraron diferencias significativas (p<0.05). Bajo las condiciones de este estudio se concluye que la mejor técnica de preparación de la base, es utilizando baño ultrasónico con etanol al 100 por ciento durante 5 minutos después de ser arenados con óxido de aluminio nuevo

Faults in the adhesion of brackets occur frequently and generally the use of a new bracket is required. With the introduction of the sanded technique it has been demonstrated that the brackets can be reused by subjecting them to a cleaning process, thereby improving adhesion. The objective of the study is comparer the tensile strength to the brackets sanded by means of new and recycled aluminum oxide, both with and without ultrasound. The assessment of tensile strength of the new and recycled base of brackets subjected to a sanding process of with new and recycled aluminum oxide in Instrom universal test machine of 80 first and second human premolars, divided in 5 groups of 16-piece: (C) used new brackets,  (AN) used new aluminum oxide  sanded brackets,  (AN+U) new aluminum oxide sanded plus ultrasound, (AR) recycled sanded, and (AR+U) recycled sanded plus ultrasound. The same type of brackets and adhesion system were used in all groups. It was demonstrated that the brackets AN increased the tensile strength and it increases even more when putting the attachments to an ultrasonic bath.  In the case of AR, their tensile strength diminished considerably, but when put under the ultrasonic bath, values were very close to those of the control group.  The t-student test, it was found that groups C vs. AN, AN vs. AN+U, and C vs. AR+U did not have significant statistical differences.  However, in groups C vs. AN+U, C vs. AR, AN vs. AR, AN vs. AR+U, AN+U vs. AR+U statistically significant differences were found. The tensile strength analysis allow concluding that the best preparation of the base technique is to use a bath in an ultrasound device with 100 percent ethylic alcohol for 5 minutes after being sanded with new aluminum oxide

The Orthosystem--a new implant system for orthodontic anchorage in the palate.

The present report describes the design and first clinical experiences of a newly developed endosseous orthodontic implant anchor system (Orthosystem, Institut Straumann, Waldenburg, Switzerland) for palatal anchorage. The 1-piece fixture made of titanium consists of a screw-type endosseous implant body (sandblasted, acid-etched, diameter 3.3 mm, lengths: 4 and 6 mm), a cylindrical polished transmucosal neck and an abutment. Clamp-caps provide attachment of square commercially available orthodontic wires (0.032 x 0.032 inch, SS) to the abutment (transpalatal bars). In a pilot study 1 fixture (implant body length: 6 mm) was inserted into the midsagittal anterior palatal region in each of 6 adult patients with Angle class II malocclusion (distocclusion 7 to 8 mm, overjet: approximately 9 mm). The treatment plan included extraction of the first maxillary premolars and retraction of the anterior teeth based on maximum anchorage of the posterior teeth without using compliance-dependent anchorage aids (headgear, class II elastics). Due to the design of the fixture only 1 simple surgical procedure was required for insertion (nonsubmerged method, 1-stage surgery). Accordingly the need for surgical exposure of the abutment for connection and wire insertion was eliminated. Thus, inconvenience to patients was reduced to a minimum. The patients are now at varying active treatment stages. The course of treatment of the most advanced case is described. Evaluation of the clinical and radiological findings after 12 months of treatment (3 months implant healing, 9 months active orthodontic treatment which is equal to the implant loading period) revealed no implant mobility/dislocation, favourable peri-implant soft tissue conditions, no marked mesial movement (approximately 0.5 mm) of the implant/transpalatal bar supported posterior teeth, and 8 mm retraction of the anterior teeth. Retrieval of the fixture and post-operative wound healing were uncomplicated. In the treatment of this case, no compliance-dependent extraoral anchorage was used, and the well aligned mandibular dentition was not bonded provide anchorage support (class II elastics).