Técnica de disyunción horizontal del reborde alveolar con bisturí piezoeléctrico y colocación de implantes en el maxilar inferior: informe de casos clínicos / Horizontal split crest technique using a piezoelectric scalpel and immediate implant placement in the jaw: report of clinical cases

Objetivo: Presentar una técnica quirúrgica de disyunción con bisturí piezoeléctrico y expansión de rebordes delgados en maxilar inferior que permita la colocación de implantes en la posición tridimensional correcta en el mismo acto quirúrgico. Casos clínicos: Se presenta la resolución de dos casos clínicos de pacientes que acudieron a la Cátedra de Odontología Integral Adultos de la Facultad de Odontología de la Universidad de Buenos Aires. Ambos requerían la colocación de implantes en sectores posteroinferiores. Las imágenes tomográficas mostraban adecuada altura del reborde alveolar pero deficiente espesor para la colocación de implantes en la posición tridimensional correcta. Se decidió realizar una técnica de disyunción horizontal del reborde alveolar con bisturí piezoeléctrico, expansión del reborde y colocación de implantes e injerto óseo particulado de forma simultánea. Luego de 3 meses, se efectuó la segunda cirugía para iniciar la rehabilitación protésica. Conclusión: La técnica de disyunción horizontal del reborde alveolar mediante el uso del bisturí piezoeléctrico permitió ubicar al implante en la posición tridimensional correcta dentro del tejido óseo nativo sin la necesidad de realizar regeneraciones complejas en rebordes alveolares delgados (AU)

Aim: Present the horizontal split crest technique with a piezoelectric scalpel and the immediate implant placement in the correct tridimensional position, in thin mandibular alveolar ridges. Cases report: The surgical resolutions of 2 clinical cases of patients who attended the Adult Integral Dentistry Chair of the Faculty of Dentistry of the UBA, are presented. Both patients required implant placement in posterior madibular residual ridge. The tomographic images showed adequate height of the alveolar ridge but poor thickness for implants placement in a correct three-dimensional position. It was decided to perform a horizontal split crest technique of the alveolar ridge with piezoelectric scalpel, ridge expansion, and immediate implant placement with xenograft. After 3 months, the second surgery was performed to start with the prosthetic rehabilitation. Conclusion: The horizontal split crest technique using a piezoelectric scalpel, allowed immediate implant placement in the correct tridimensional position within native bone tissue, avoiding a guided bone regeneration technique, in these cases with thin alveolar ridges (AU)

Direct Intracochlear Acoustic Stimulation Using a PZT Microactuator.

Combined electric and acoustic stimulation has proven to be an effective strategy to improve hearing in some cochlear implant users. We describe an acoustic microactuator to directly deliver stimuli to the perilymph in the scala tympani. The 800 µm by 800 µm actuator has a silicon diaphragm driven by a piezoelectric thin film (e.g., lead-zirconium-titanium oxide or PZT). This device could also be used as a component of a bimodal acoustic-electric electrode array. In the current study, we established a guinea pig model to test the actuator for its ability to deliver auditory signals to the cochlea in vivo. The actuator was placed through the round window of the cochlea. Auditory brainstem response (ABR) thresholds, peak latencies, and amplitude growth were calculated for an ear canal speaker versus the intracochlear actuator for tone burst stimuli at 4, 8, 16, and 24 kHz. An ABR was obtained after removal of the probe to assess loss of hearing related to the procedure. In some animals, the temporal bone was harvested for histologic analysis of cochlear damage. We show that the device is capable of stimulating ABRs in vivo with latencies and growth functions comparable to stimulation in the ear canal. Further experiments will be necessary to evaluate the efficiency and safety of this modality in long-term auditory stimulation and its ability to be integrated with conventional cochlear implant arrays.

Acceleration of tooth movement during orthodontic treatment--a frontier in orthodontics.

Nowadays, there is an increased tendency for researches to focus on accelerating methods for tooth movement due to the huge demand for adults for a shorter orthodontic treatment time. Unfortunately, long orthodontic treatment time poses several disadvantages like higher predisposition to caries, gingival recession, and root resorption. This increases the demand to find the best method to increase tooth movement with the least possible disadvantages. The purpose of this study is to view the successful approaches in tooth movement and to highlight the newest technique in tooth movement. A total of 74 articles were reviewed in tooth movement and related discipline from 1959 to 2013. There is a high amount of researches done on the biological method for tooth movement; unfortunately, the majority of them were done on animals. Cytokine, PTH, vitamin D, and RANKL/RANK/OPG show promising results; on the other hand, relaxin does not accelerate tooth movement, but increases the tooth mobility. Low-level laser therapy has shown positive outcome, but further investigation should be done for the best energy and duration to achieve the highest success rate. Surgical approach has the most predictable outcomes but with limited application due to its aggressiveness. Piezocision technique is considered one of the best surgical approaches because it poses good periodontal tissue response and excellent aesthetic outcome. Due to the advantages and disadvantages of each approach, further investigations should be done to determine the best method to accelerate tooth movement.

Hemostasis control in endodontic surgery: a comparative study of calcium sulfate versus gauzes and versus ferric sulfate.

INTRODUCTION: Calcium sulfate (CaS) is a simple, biocompatible material with a long history of safe use in different fields of medicine. CaS is a rapidly resorbing material that leaves behind a calcium phosphate lattice, which promotes bone regeneration and hemostasis. The aim of this study was a clinical evaluation of the hemostatic effect of CaS hemi-hydrate (CaSO4), commonly known as plaster of Paris, in endodontic surgery. METHODS: Twenty-four patients with 31 periradicular lesions were enrolled in this study. The apical roots were exposed, and the bleeding would have made it difficult to correctly fill the root-end cavities. To avoid such an inconvenience, the teeth were divided into 3 groups. Hemostasis was attempted by using CaS in 11 teeth (group I), gauze tamponade in another 10 teeth (group II), or 20% ferric sulfate in the last 10 teeth (group III). RESULTS: Control of the bleeding was achieved in all teeth of group I, whereas in group II adequate hemostasis was achieved in 3 of 10 cases and in group III in 6 of 10 cases. CONCLUSIONS: The use of CaS completely eliminated the bleeding, with a very good level of hemostasis.

Comparative evaluation of surgical outcome after removal of impacted mandibular third molars using a Piezotome or a conventional handpiece: a prospective study.

Our aim was to compare the use of a conventional rotary handpiece and a Piezosurgical unit for extraction of lower third molars. We studied 40 patients, who were allocated alternately to have the third molar removed with either the handpiece or the Piezosurgical unit. Pain, trismus, and oedema were evaluated at baseline and then postoperatively, together with paraesthesiae, on postoperative days 1, 3, 5, 7, and 15. Damage to surrounding tissue was checked on the same day whereas dry socket was evaluated from postoperative day 3 onwards. More patients complained of pain in the conventional group, they also required more analgesics, and they developed trismus more often than in the Piezosurgery group. There was also significantly more postoperative swelling in the conventional group. Patients were also evaluated using the subjective Postoperative Symptom Severity (PoSSe) scale. Our results suggest that apart from some inherent limitations with the Piezotome, it is a valuable alternative for extraction of third molars.