Peter Maurer

Heat production during different ultrasonic and conventional osteotomy preparations for dental implants

OBJECTIVESnThe purpose of this study was to evaluate the intraosseous temperature changes during ultrasonic and conventional implant site preparation in vitro with respect to the effect of load and irrigation volume.nnnMATERIAL AND METHODSnImplant sites were prepared using two different ultrasonic devices (Piezosurgery, Mectron Medical Technology and VarioSurg, NSK) and one conventional device (Straumann) at loads of 5, 8, 15 and 20 N and with irrigation volumes of 20, 50 and 80 ml/min. During implant site preparation, temperatures were measured in fresh, equally tempered bovine ribs using two thermocouples placed at a distance of 1.5 mm around the drilling site in cortical and cancellous bone. The preparation time was recorded.nnnRESULTSnThe heat production and time required for implant site preparation using both ultrasonic devices were significantly higher than those for conventional drilling (P<0.01). Increased loading had no effect on heat production. A higher irrigation volume was associated with a diminished temperature increase in the cortical bone for ultrasonic but not for conventional drilling, which resulted in significantly lower temperatures in cortical as compared with cancellous bone during ultrasonic implant site preparation.nnnCONCLUSIONSnUltrasonic implant site preparation is more time consuming and generates higher bone temperatures than conventional drilling. However, with the levels of irrigation, ultrasonic implant site preparation can be an equally safe method.

Bisphosphonate-related osteonecrosis of the maxilla and sinusitis maxillaris

Bisphosphonates (BPs) are widely used as bone-stabilizers, but side effects of BP therapy include bisphosphonate-related osteonecrosis of the jaw (BRONJ), which is resistant to therapy. The aim of this study was to evaluate the outcome of maxillary BRONJ involving sinusitis maxillaris. 21 patients presenting with maxillary BRONJ, from 2005 to 2008, were included in the study. In 18 cases BP had been administered for carcinoma and in 3 cases for osteoporosis, with an average exposure time of 47.4 months. 12 patients spontaneously developed BRONJ. The 10 patients diagnosed with stage III BRONJ presented with concomitant sinusitis maxillaris. Despite treatment, there were six recurrences of BRONJ, four of them with additional sinusitis maxillaris. Whether BRONJ occurred spontaneously or after extraction there was no difference in the outcome. Patients with advanced maxillary BRONJ often suffer from sinusitis maxillaris, both of which are frequently resistant to therapy.

Intraoperative evaluation of bony margins with frozen-section analysis and trephine drill extraction technique: A preliminary study.

The aim of this study was to examine the use of trephine drill specimens from mandible bony margins subjected to standard histologic fresh‐frozen processing for intraoperative documentation of malignant bony infiltration in oral cancer.

Trigeminocardiac Reflex, Bilateral Sagittal Split Ramus Osteotomy, Gow-Gates Block: A Randomized Controlled Clinical Trial

PURPOSEnThe behavior of trigeminocardiac reflex (TCR) during maxillofacial surgeries has not yet been sufficiently studied and knowledge of its behavior is limited to some case reports. The present study aimed to assess the occurrence of TCR in bilateral sagittal split ramus osteotomy and to determine the possible effect of Gow-Gates block on its incidence.nnnMATERIALS AND METHODSnTwenty candidates for bilateral sagittal split ramus osteotomy (included were American Society of Anesthesiologists I Class III patients with a prognathism of 3 to 5 mm) were given routine general anesthesia after at least 12 hours of fasting. All patients received Gow-Gates mandibular nerve block on 1 random side (case ramus; the other side was used as the control) after induction of general anesthesia before surgery. Pulse rate was recorded at baseline, soft tissue cutting, bone cutting, sagittal splitting, setback manipulation, and recovery. Mean pulse rate values were compared statistically using t test for the 2 sides in patients.nnnRESULTSnNo statistically significant differences were found between the blocked and control sides except during ramus sagittal splitting and setback manipulation (P < .0001), when a significantly decreased pulse rate was recorded for the control ramus compared with the blocked ramus.nnnCONCLUSIONSnThe present study provides further evidence for the complex neurophysiologic mechanism and probable prevention of peripheral TCR. The results of the present study should be further validated through future studies but already provide strong evidence that peripheral and central TCR may act differently based on slightly different pathways.

Micromorphometrical analyses of five different ultrasonic osteotomy devices at the rabbit skull

OBJECTIVESnThe recently introduced ultrasonic osteotome procedure is an alternative to conventional methods of osteotomy. The aim of the present study was to establish the differences between five recently introduced ultrasonic osteotomes and to perform micromorphological and quantitative roughness analyses of osteotomized bone surfaces.nnnMATERIALS AND METHODSnFresh, standard-sized bony samples were taken from a rabbit skull using the following ultrasonic osteotomes: the Piezosurgery 3 with insert tip OT7, Piezosurgery Medical with insert tip MT1-10, Piezon Master Surgery with insert tip SL1, VarioSurg with inert tip SG1, and Piezotome 2 with insert tip BS1 II. The required duration of time for each osteotomy was recorded. The prepared surfaces were examined via light microscopy, environmental surface electron microscopy (ESEM), and confocal laser scanning microscopy (CLSM).nnnRESULTSnAll of the investigated piezoelectric osteotomes preserved the anatomical structure of bone. The mean roughness values of the osteotomized bone edge obtained using the investigated piezoelectric osteotomes were as follows: 2.47 μm (Piezosurgery 3), 9.79 μm (Piezosurgery Medical), 4.66 μm (Piezon Master Surgery), 6.38 μm (VarioSurg), and 6.06 μm (Piezotome 2). Significantly higher roughness values were observed when using the Piezosurgery Medical in comparison with those achieved by the Piezosurgery 3 (P<0.0001) and Piezon Master Surgery (P=0.002). Different osteotomy durations were achieved using the different piezoelectric osteotomes: 144 s (Piezosurgery 3), 126 s (Piezosurgery Medical), 142 s (Piezon Master Surgery), 149 s (VarioSurg), and 137 s (Piezotome 2).nnnCONCLUSIONSnIn the present study, micromorphological differences following the use of various ultrasonic devices were clearly identified. According to this study, it can be concluded that the power and the composition of the teeth of the insert tip might impact procedure duration and cutting qualities.

Styloid–carotid artery syndrome treated surgically with Piezosurgery: A case report and literature review

Styloid-carotid artery syndrome was first described by Eagle and is associated with cervical and facial pain caused by head movement resulting from mechanical compression of the carotid nerve plexus due to an elongated styloid process. The case of a 49-year-old man with persistent cervical pain, neurological symptoms and an elongated styloid process of 7.5 cm is reported here; this patient was successfully treated using Piezosurgery. In addition, a literature review is included.

Auflichtmikroskopische Untersuchungen an der Kaninchenkalotte nach ultraschallgestützter und konventioneller Osteotomie / Light microscopic examination of rabbit skulls following conventional and Piezosurgery®osteotomy

Zusammenfassung Hintergrund: Das seit kurzem im klinischen Gebrauch befindliche ultraschallgestützte Osteotomieverfahren Piezosurgery®, stellt eine Alternative zu den konventionellen Verfahren der Osteotomie dar. Ziel der vorliegenden Studie war es, mittels auflichtmikroskopischer Untersuchungsmethoden einen morphologischen Vergleich konventioneller Osteotomiemethoden (Lindemannfräse und Mikrostichsäge) mit dem neuen, ultraschallgestützten Verfahren hinsichtlich der Oberflächenmorphologie durchzuführen. Material und Methode: Zwölf frisch euthanasierten Kaninchen wurden Knochenstücke normierter Größe von der Schädelkalotte entnommen. Folgende Osteotomieverfahren kamen zum Einsatz: rotierendes Instrument (Lindemannfräse), Mikrosäge, Piezosurgery® mit den Aufsätzen OT6 und OT7. Die für die Osteotomie benötigten Zeiten wurden gemessen. Die osteotomierten Oberflächen wurden auflichtmikroskopisch bei 40-facher und 100-facher Vergrößerung untersucht. Ergebnisse: Die ultraschallgestützte Osteotomie benötigte signifikant mehr Zeit als die konventionellen Osteotomieverfahren (p<0,05). In den Untersuchungen ließ sich an den nativ belassenen Knochenproben nach Einsatz des ultraschallgestützen Osteotomieverfahrens der typische Aufbau der Schädelkalotte mit Tabula externa, Diploe und Tabula interna nachvollziehen. Hingegen wiesen die spongiösen Strukturen der Diploe nach Einsatz der konventionellen Osteotomieverfahren deutliche Veränderungen auf. Die Spongiosaräume waren mit Knochendebris gefüllt, und trabekuläre Strukturen waren zerstört. Insbesondere nach Einsatz der Mikrostichsäge imponierte die Oberfläche verdichtet und wies Sägerillen auf. Schlussfolgerung: In der vorliegenden Untersuchung konnten eindeutige morphologische Unterschiede zwischen den Knochenoberflächen nach konventionellen Osteotomieverfahren und dem ultraschallgestützten Verfahren aufgezeigt werden. Es ist denkbar, dass diese den Ablauf der Knochenheilung nach der Osteotomie beeinflussen. Weiterführende Studien zur Knochenheilung nach Einsatz unterschiedlicher Osteotomietechniken erscheinen notwendig. Abstract Introduction: The novel ultrasonic osteotomy technique (Piezosurgery®) is an alternative to conventional osteotomy devices. The aim of the present study was to carry out morphological comparison of the bone surface using conventional osteotomy techniques in comparison to the rather new ultrasonic osteotomy technique by means of a reflected-light microscopic examination. Materials and methods: Following the sacrifice of 12 rabbits, 24 standardized bone samples were removed from the skull. The osteotomy devices used were a rotating instrument (Lindemann bur), an oscillating micro-saw, and an ultrasonic osteotomy device (Piezosurgery®) with insert tips OT6 and OT7. The times needed for osteotomy were measured. The bone surfaces were examined using a reflected-light microscope with a magnification of 40× and 100×. Results: Osteotomy with Piezosurgery® is significantly more time consuming than osteotomy with conventional methods (p<0.05). Following osteotomy with the ultrasonic device, the reflected-light microscopic examinations of the unmodified bone samples revealed typical bone structure of the calvaria, including compacta externa, diploe and compacta interna. On the contrary, following osteotomy with the conventional devices, the diploe structure presented distinct modifications. The cancellous spaces were filled with bone debris, and the cancellous structure was demolished. The samples prepared by the micro-saw technique showed a superficially condensed and grooved surface. Conclusion: In the present study, well-defined differences were observed following osteotomy with conventional devices and osteotomy with the ultrasonic device. The integrity of the bony structure observed after the ultrasonic technique could benefit the bone healing process. Further studies dealing with the bone healing process after using different osteotomy techniques are recommended.

Alveolar bone stress around implants with different abutment angulation: an FE-analysis of anterior maxilla.

Objectives:To comparatively assess the masticatory stress distribution in bone around implants placed in the anterior maxilla with three different labial inclinations. Materials and Methods:Three-dimensional finite element models were fabricated for three situations in anterior maxilla: (1) a fixture in contact with buccal cortical plate restored by straight abutment, (2) a fixture inclined at 15 degrees, and (3) 20 degrees labially restored with corresponding angled abutment. A palatal bite force of 146 N was applied to a point 3 mm below the incisal edge. Stress distribution around the bone-fixture interface was determined using ANSYS software. Results:The maximum compressive stress, concentrated in the labial crestal cortical bone, was measured to be 62, 108, and 122 MPa for 0-, 15-, and 20-degree labially inclined fixtures, respectively. The maximum tensile stress, concentrated in the palatal crestal cortical bone, was measured to be 60, 108, and 120 MPa for 0-, 15-, and 20-degree labially inclined fixtures, respectively. Conclusions:While all compressive stress values were under the cortical yield strength of 169 MPa, tensile stress values partially surpassed the yield strength (104 MPa) especially when a 20-degree inclination was followed for fixture placement.

Orbital complications due to an acute odontogenic focus in a child. A case report

The full clinical manifestations of complications due to odontogenic foci are rarely seen in daily dental practice and can take a clinically foudroyant course of development in young people owing to anatomic conditions, as demonstrated in this clinical case in a 12-year-old girl. Endodontic treatment of the first right upper molar was started owing to increasing toothache and swelling of fossa canina and the periorbital region. During the course of treatment, the patient exhibited an acute increase in orbital inflammation, which required immediate surgical intervention with postsurgical intravenous antibiotic administration. This case should serve to emphasize the crucial requirement for intensive attention to orbital symptoms after dental procedures.

Material attrition and bone micromorphology after conventional and ultrasonic implant site preparation.

OBJECTIVESnLittle is known about the recently introduced ultrasonic implant site preparation. The purpose of this study was to compare material attrition and micromorphological changes after ultrasonic and conventional implant site preparations.nnnMATERIAL AND METHODSnImplant site preparations were performed on fresh bovine ribs using one conventional (Straumann, Freiburg, Germany) and two ultrasonic (Piezosurgery; Mectron Medical Technology, Carasco, Italy and Variosurg; NSK, Tochigi, Japan) systems with sufficient saline irrigation. Sections were examined by environmental scanning electron microscopy (ESEM). Energy-dispersive X-ray spectroscopy (EDX) was performed to evaluate the metal attrition within the bone and the irrigation fluid.nnnRESULTS ESEMnAfter conventional osteotomy, partially destroyed trabecular structures of the cancellous bone that were loaded with debris were observed, whereas after ultrasonic implant site preparations, the anatomic structures were preserved. EDX: None of the implant site preparation methods resulted in metal deposits in the adjacent bone structures. However, within the irrigation liquid, there was significantly higher metal attrition with ultrasonic osteotomy (P < 0.0001 and P < 0.0001 for Mectron and NSK, respectively). Whereas for Straumann system used, 15.5% of the SEM/EDX findings were drill-origin metals, this percentage increased to 37.3% and 37.9% with the application of Mectron and NSK, respectively.nnnCONCLUSIONSnUltrasonic implant site preparation is associated with the preservation of bone microarchitecture and with the increased attrition of metal particles. Therefore, copious irrigation seems to be even more essential for ultrasonic implant site preparation than for the conventional method.