Correlation of Fracture Resistance of Dental Implants and Bite Force in Dogs described in the literature: An In Vitro Study.

Dental implants are not routinely used for rehabilitation in veterinary dentistry. For some veterinarians, further studies are necessary to be considered for clinical use in animals. The objective of the present in vitro study was to evaluate static fatigue of dental implants and to correlate that with the bite strength of dogs described in the literature. Sixty implants and abutments were used with the smallest diameter of each brand of implant utilized in the study. Three groups (n = 20) were created on the basis of the implant diameter, all with external hex connector: 3.30 mm (group 1), 4.0 mm (group 2) and 5.0 mm (group 3). All groups were subjected to quasi-static loading at 30° to the implant's long axis in a universal machine (model AME-5 kN). The mean fracture strength for group 1 was 964 ± 187 N, for group 2 was 1618 ± 149 N and for group 3 was 2595 ± 161 N. Significant differences between the groups with respect to resistance after the load applications were observed (P < .05). The diameter of implants affects the resistance to external forces during the application of non-axial strength (off-axis loading) and must be considered during the planning of rehabilitation to avoid problems.

La respuesta tisular a implantes dentales con plataforma reducida (platform switching) / Tissue response to dental implants with platform switching

La evolución en los diseños de los sistemas de implantes y en la configuración de los pilares protésicos ha desarrollado el concepto de plataforma reducida que comprende la colocación de un pilar más estrecho que la plataforma del implante para aumentar su distancia de la interfase hueso-implante. La plataforma reducida es considerada un factor importante para preservar la estabilidad del hueso crestal y de los tejidos blandos y asegurar el éxito de los implantes dentales a largo plazo. La plataforma reducida reduce las fuerzas oclusales y la contaminación bacteriana en la interfase entre el hueso crestal y el implante. Los estudios experimentales en animales y clínicos en pacientes muestran su eficacia para prevenir la pérdida ósea y de los tejidos blandos periimplantarios

The evolution of designs of implant systems and abutments configurations has developed the concept of platform-switching that involves the connection of a narrower abutment to the platform implant to allow horizontal distance of the interface bone-implant. Platform-switching is considered an important factor to preserve the stability of crestal bone and soft tissue ensuring the success of dental implants in the long-term follow-up. Platform-switching reduces the forces of occlusal loading and bacterial contamination in the interface between the crestal bone and the implant. Experimental studies in animals and clinical studies in patients showed that implants with platform-switching have demonstrated the effectiveness to prevent peri-implant bone loss and subsequent soft tissue los

Effect of implant placement depth on the peri-implant bone defect configura-tions in ligature-induced peri-implantitis: An experimental study in dogs

Background: The subcrestal placement of implant platform has been considered a key factor in the preservation of crestal bone, but the influence of implant placement depth on bone remodeling combined with peri-implantitis is not fully understood. The aim of this study was to assess the effect of the crestal or subcrestal placement of implants on peri-implant bone defects of ligature-induced peri-implantitis in dogs. Material and Methods: Eight weeks after tooth extraction in six beagle dogs, two different types of implants (A: OsseoSpeed(TM), Astra, Mölndal, Sweden; B: Integra-CP(TM), Bicon, Boston, USA) were placed at either crestal or subcrestal (-1.5 mm) positions on one side of the mandible. Ligature-induced peri-implantitis was initiated four weeks after the installation of the healing abutment connections. After 12 weeks, tissue biopsies were processed for histological analyses. Results: Supra-alveolar bone loss combined with a shallow infrabony defect was observed in crestal level implants while deep and wide infrabony defects were present in subcrestal level groups. Subcrestal groups showed significantly greater ridge loss, depths and widths of infrabony defects when compared to crestal groups (P <0.001). Conclusions: Within the limitations of the animal study, it can be stated that the implants at subcrestal position displayed greater infra-osseous defect than implants at crestal position under an experimental ligature-induced peri-implantitis (AU)

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Feline Dental Implants: Long-Term Follow-up of Two Cases.

Dental implants have become an option for replacement of lost canine teeth in cats. Although cats appear to manage well after a canine extraction, complications such as lip entrapment can occur after maxillary canine tooth extraction. Even cats with a complicated crown fracture of the maxillary canine tooth that have had root canal therapy can develop lip entrapment. This can lead to painful lip ulcers and potential need for further dental treatment. Canine tooth replacement with a dental implant and prosthodontic crown is, in the authors' experience, a predictable option that can be offered to clients who would like to replace a lost canine tooth. This report will discuss 2 long-term cases of maxillary canines replaced by dental implants/crowns.

Dental Implants and Incisor Bridge Placement in a Dog.

Veterinary dentistry has tended to follow the trends and advancements in the human dental field. As for any procedure performed on a patient, whether human or animal, an informed decision is based on the available evidence regarding treatment options. This is certainly true for the more involved treatments in veterinary dentistry which can include the disciplines of endodontics and dental implantology. A number of published case reports have been accepted by the specialty that endodontic therapy is indeed a predictable and a valuable service that can be offered to pet owners. Oral implantology has become an accepted and predictable procedure in the human dental field and can now be offered to pet owners if performed by suitable trained veterinary clinicians. The success rate for endosseous implant osseointegration is very high in humans. Success rates are also very high in animals used for implantology research. Canine studies have shown good bone-to-implant contact of around 73% in osseointegrated endosseous implants based on histological sections. Radiographic and histological findings demonstrate stable alveolar crestal bone levels after loading endosseous implants for up to 12 months in a dog model. This article discusses use of dental implants in the rostral mandible of a companion dog to replace periodontally diseased incisors, their restoration, to return the animal to full dental function and 3-year follow-up.

Drilling dimension effects in early stages of osseointegration and implant stability in a canine model

BACKGROUND: This study histologically evaluated two implant designs: a classic thread design versus another specifically designed for healing chamber formation placed with two drilling protocols. MATERIAL AND METHODS: Forty dental implants (4.1 mm diameter) with two different macrogeometries were inserted in the tibia of 10 Beagle dogs, and maximum insertion torque was recorded. Drilling techniques were: until 3.75 mm (regular-group); and until 4.0 mm diameter (overdrilling-group) for both implant designs. At 2 and 4 weeks, samples were retrieved and processed for histomorphometric analysis. For torque and BIC (bone-to-implant contact) and BAFO (bone area fraction occupied), a general-linear model was employed including instrumentation technique and time in vivo as independent. RESULTS: The insertion torque recorded for each implant design and drilling group significantly decreased as a function of increasing drilling diameter for both implant designs (p < 0.001). No significant differences were detected between implant designs for each drilling technique (p > 0.18). A significant increase in BIC was observed from 2 to 4 weeks for both implants placed with the overdrilling technique (p < 0.03) only, but not for those placed in the 3.75 mm drilling sites (p > 0.32). CONCLUSIONS: Despite the differences between implant designs and drilling technique an intramembranous-like healing mode with newly formed woven bone prevailed

Immediate semi-static loading using compression healing abutments: a stability study in dogs.

Loading in implant dentistry to accelerate prosthodontic treatment has been receiving increasing interest. The aim of this study was to investigate the effect of an early controlled lateral loading (after 7 days) on the establishment of osseointegration by means of resonance frequency analysis. Two groups of six beagle dogs each were used. Group I had implants without loading. Group II had implants loaded with a new prototype compression abutment that created controlled semi-static loading. Loaded implants showed slightly better stability after 5 weeks of healing, but the difference was not significant. We concluded that controlled loading is beneficial to maintain, and even improve, stability during the early critical healing period.

Intramuscular 30 percent polymethylmethacrylate (PMMA) implants in a non-protein vehicle: an experimental study in rats / Implante intramuscular de polimetilmetacrilato (PMMA) 30 por cento, associado a veículo não-proteico: estudo experimental em ratos

INTRODUCTION: In the present study, the stability and biocompatibility of a 30 percent polymethylmethacrylate (PMMA) filling material implanted in the masseter muscle of rats were investigated according to the cytologic characteristics presented in the graft versus host reaction. METHODS: The study included 20 rats, which were divided into 4 groups: groups I, II, III, and IV corresponded to animals evaluated 7, 14, 45, and 60 days after surgery, respectively. The implant was placed in the right masseter muscle at the level of the mandibular angle. RESULTS: After 7 days, lymphoplasmacytic inflammatory infiltrates, a fibrous capsule, a large number of neutrophils, macrophages, and exudate were observed. The second group (14 days) showed granulation tissue composed of a lymphoplasmacytic inflammatory infiltrate, newly formed vessels, and a fibrous capsule. However, the second group also exhibited regeneration of the muscle fibers, and a decreased number of neutrophils and exudate. After 45 and 60 days, the inflammatory infiltrate decreased in intensity compared to the first 2 groups. CONCLUSIONS: The inflammatory reaction caused by PMMA is transient and does not compromise the function and the shape of the masseter muscle tissue, suggesting that PMMA is biocompatible.

INTRODUÇÃO: Este trabalho busca avaliar, em ratos, a estabilidade e a biocompatibilidade de um material de preenchimento à base de polimetilmetacrilato (PMMA) a 30 por cento implantado no músculo masseter, por meio do padrão, e a organização reacional no tecido receptor. MÉTODO: Foram utilizados 20 ratos, divididos em quatro grupos: grupo I, que correspondeu ao período de 7 dias de pós-operatório; grupo II, de 14 dias; grupo III, de 45 dias; e grupo IV, de 60 dias. O implante foi realizado no músculo masseter direito, na região do ângulo da mandíbula. RESULTADOS: No período de 7 dias, observou-se presença de infiltrado inflamatório linfoplasmocitário, com formação de cápsula fibrosa e presença de grande número de neutrófilos, macrófagos e formação de exsudatos. Em 14 dias, observou-se a formação de um tecido de granulação composto por infiltrado inflamatório linfoplasmocitário, vasos de neoformação e cápsula fibrosa. Porém, nesse tempo experimental, nota-se a regeneração das fibras musculares e a diminuição do número de neutrófilos e exsudatos. Após 45 dias e 60 dias, observou-se, no tecido muscular, diminuição da intensidade do infiltrado inflamatório, comparativamente aos tempos experimentais anteriores. CONCLUSÕES: A reação inflamatória provocada pelo PMMA é transitória e não compromete as funções e o contorno desse tecido muscular, o que sugere que o PMMA é biocompatível.

El área cervical de implantes dentales presenta mayor formación ósea que el área apical en diferentes condiciones de diseño y carga: resultados preliminares / The cervical area of dental implants present more osseous formation than apical area in different load and design condition: preliminary results

Los implantes dentales han evolucionado de forma sustancial en los últimos 40 años; sin embargo, dudas sobre las características de la reparación ósea continúan toda vez que nuevos diseños y nuevos métodos quirúrgicos son aplicados. El objetivo de esta investigación es evidenciar la presencia de tejido mineralizado en diferentes regiones del implante. Se elaboró un estudio basado en un modelo de restauración inmediata, aplicado en la mandíbula de 7 canes machos. Se realizaron las exodontias de los premolares mandibulares y, después de 3 meses de recuperación, se instalaron 2 implantes endóseos bilaterales, siendo uno de tipo cónico y otro de tipo cilíndrico. Después de dos periodos de sacrificio se realizo una evaluación histomorfométrica en los cortes seleccionados. Los resultados se presentan de forma porcentual estableciendo comparaciones entre las áreas cervical, media y apical. Los implantes de morfología cónica sometidos al modelo de restauración inmediata, presentaron mayor formación ósea en todos los niveles evaluados. En todas las condiciones de trabajo el área cervical presentó mayor presencia de tejido mineralizado que el área apical. Concluimos que el modelo de restauración inmediata no es un obstáculo para la instalación de la secuencia apropiada de reparación ósea y que diferentes factores deben estar asociados a la mayor formación ósea presente en el área cervical de los implantes dentales.

Dental implants have evolved of substantial form in the last 40 years; however, doubt about osseous repair characteristic are maintained because new design and surgical method are applied. The aim of this research is show the mineralized tissue in different areas of the implant. Was done a study based to a immediate load model applied in 7 male dogs mandible. Was realized the dental extractions of de bilateral mandibles bicusp and after to 3 month of recuperations was installed two bilaterally implants, been conical and cylindered shape. After of two sacrifices period was realized a histomorphometric analysis in the selection cut. The results are present with perceptual form, establishing cervical, meddle and apical comparison. Conical implants with immediate restoration model were present more osseous formations in all evaluated level. For all conditions of work, cervical area presented more mineralized tissue than apical area. We conclude that immediately restoration model it is not an obstacle for the installation of the appropriate sequence for the osseous reparation and that different factors have been associated to the more osseous formation in the cervical area of the dental implants.

Radiographic evaluation of tooth drift after cheek tooth extraction and insertion of an intra-alveolar prosthesis in ponies.

The aim of the study was to investigate post-extraction tooth drift in ponies and the influence of an intra-alveolar prosthesis. The maxillary 08 was bilaterally repulsed in five ponies under general anaesthesia. On one side the alveolus was left to granulate, and on the other a synthetic bone substitute prosthesis was fitted. Standard radiographic projections of the head were taken monthly during the first year and at 24 months post-operatively. Different cephalometric parameters were measured and statistically analyzed. Rostral and caudal drift were recognized in molar and premolar teeth, respectively. The prosthesis significantly slowed down tooth drift (P<0.001). Although differences in the degree of secondary mandibular overgrowths (on 06s, 11s and 08s) were found between treatments, this had no important clinical consequences. Premolars showed significantly more tooth wear in comparison with molars (P<0.001). Tooth attrition was higher in the prosthesis treated sides (P<0.001).

The osteoinductive potential of MTA (Mineral Trioxide Aggregate): a histologic study in rabbits

The objective of this study was to investigatebone response after implantation of MTA (MineralTrioxide Aggregate) in the rabbit mandible.Experiments were carried out on the rightmandibular body of 8 adult male rabbits. Theanimals were divided into two groups (controlgroup and test group). In this in vivo study, MTAwas used as an interpositional graft material incritical-size bone defects of rabbit mandibles.The animals were sacrificed on day 30 after surgery.The samples obtained from the mandibleswere subjected to histological procedures, whichpermitted the collection of sections with a thicknessof 60±10ìm. The sections were stained withHaematoxylin and Eosin and Goldner Trichromestain and examined under a light microscope.No important inflammatory reactions weredetected in any of the samples of the treatedgroup. The results confirm the excellent biocompatibilityof MTA. The implantation of MTA inbone defects led to bone regeneration 4 weeksafter surgery. However, the growth rate was notsignificant and the amount of newly formed bonewas limited with the use of MTA in this specificapplication. Sample examination did not suggestcomplete evidence of new bone growth from eitheran inductive or conductive perspective.The objective of this study was to investigatebone response after implantation of MTA (MineralTrioxide Aggregate) in the rabbit mandible.Experiments were carried out on the rightmandibular body of 8 adult male rabbits. Theanimals were divided into two groups (controlgroup and test group). In this in vivo study, MTAwas used as an interpositional graft material incritical-size bone defects of rabbit mandibles.The animals were sacrificed on day 30 after surgery.The samples obtained from the mandibleswere subjected to histological procedures, whichpermitted the collection of sections with a thicknessof 60+-10microm. The sections were stained withHaematoxylin and Eosin and Goldner Trichromestain and examined under a light microscope.No important inflammatory reactions weredetected in any of the samples of the treatedgroup. The results confirm the excellent biocompatibilityof MTA. The implantation of MTA inbone defects led to bone regeneration 4 weeksafter surgery. However, the growth rate was notsignificant and the amount of newly formed bonewas limited with the use of MTA in this specificapplication. Sample examination did not suggestcomplete evidence of new bone growth from eitheran inductive or conductive perspective

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The use of a particulate, microporous, calcified copolymer as a ridge maintenance device in dogs.

HTR polymer Synthetic Bone was found to be an osteoconductive, biocompatible, reliable nonresorbable matrix ridge maintenance material (Ridge Preservation). When used as socket implants immediately after the extraction of teeth over a one-year period in 16 beagle dogs, HTR was observed clinically and radiographically and compared with controls (unimplanted, sutured) extraction sites. As the control areas resorbed, the stability and effectiveness of the synthetic bone material in the operative sites became more clearly delineated. Quantitative analyses could not be made using radiographic techniques, but radiographs supported by subjective clinical observations as well as study casts taken of the height and width of the implanted areas, showed greater ridge retention compared with controls. Histological sections demonstrated dense laminar bone gradually forming into and around the HTR particulate material.

[Comparative study of two different types of dental implants in dogs. Experimental study]. / Estudio comparativo de dos tipos diferentes de implantes dentarios en Perros. Estudio experimental.

Mandibular incisors were taken out in 13 adult dogs. Twenty days after the extraction, two implants either of titanium or hydroxylapatite were placed in a second operation. The clinical, pathological and radiological results suggest that metallic implants produce fibrous tissue around the implant. In most cases, fibrous tissue does not ossify and this facilitates the formation of a malunion and the mobilization of the implant. However, the results with hydroxylapatite implants appear to be satisfactory due to the formation of an osseous tissue mandibular bone. This tissue prevents the mobilization of the implant allowing support to a dental prostheses.