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Purpose: The immediate placement of single postextractive implants is increasing in the everyday clinical practice. Due to insufficient bone tissue volume, proper primary stability, essential for subsequent osseointegration, is sometimes not reached. The aim of this work was to compare two different approaches: implant bed preparation before and after root extraction. Materials and Methods: Twenty-two patients of both sexes were selected who needed an implant-prosthetic rehabilitation of the fractured first mandibular molar or presented an untreatable endodontic pathology. The sites were randomly assigned to the test group (treated with implant bed preparation before molar extractions) or control group (treated with implant bed preparation after molar extractions) by a computer-generated table. All implants were placed by the same operator, who was experienced in both traditional and ultrasonic techniques. The implant stability quotient (ISQ) and the position of the implant were evaluated. Statistical analysis was carried out. Results: In the control group, three implants were placed in the central portion of the bone septum, while eight implants were placed with a tilted axis in relation to the septum; in the test group, all implants were placed in ideal positions within the root extraction sockets. The different position of the implants between the two procedures was statistically significant. Conclusion: This work presented an innovative approach for implant placement at the time of mandibular molar extraction. Preparing the implant bed with an ultrasonic device before root extraction is a simple technique and also allows greater stability to be reached in a selective case. [ABSTRACT FROM AUTHOR]

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The aim of this study was to evaluate the usefulness of ultrasonic orthognathic surgery compared to conventional methods using powered instruments. The subjects were 146 patients in whom dentofacial deformities had been surgically corrected by a combined surgery of Le Fort I osteotomy and BSSO, and they were divided into two groups: 88 patients who underwent surgery using powered instruments and 58 patients who underwent surgery using the serrated aggressive knife tip of an ultrasonic bone cutting device. Intraoperative bleeding volume and surgical time in two groups were compared. Intraoperative bleeding volume in the ultrasonic bone cutting device group was significantly smaller by 36% than that in the powered instruments group. On the other hand, surgical time in the ultrasonic bone cutting device group was significantly longer by 11% than that in the powered instruments group. Although there was a significant correlation between intraoperative bleeding volume and operation time in each group, the regression line in the ultrasonic bone cutting device group was lower and gentler than that in the powered instruments group. Therefore, it is considered that ultrasonic orthognathic surgery with a serrated aggressive knife tip is very effective for improving safety.

An ultrasonic-assisted bone instrument can be used for the dissection of bone in spinal surgery. During surgery, the tip of such a bone instrument can touch spinal dura mater. Especially during critical re-operations, high forces can be unintentionally applied on spinal dura mater. To prevent dural tears, the influence of application parameters on the tear force shall be analyzed. Collagen foil is used as a substitute material for spinal dura mater because of its similar mechanical properties and structure. Sponge cloth is placed below collagen foil to imitate cerebrospinal fluid and nerve tissue. A 3-axis CNC-machine is used to automate the movement of the bone instrument. In a full factorial experiment the influence of amplitude, shape of movement and velocity of movement on the tear force is analyzed. Amplitude has the strongest effect because of the increase in input energy. Velocity also has a significant influence, probably because of the strain rate increasing with velocity. Thus, a surgeon should mainly reduce the amplitude and furthermore the velocity of movement to generate higher safety in critical areas.

Background: There is some concern that root resection may alter the surface features and crack formation of the previously set orthograde material. The aim of this in vitro study was to evaluate the crack formation in orthograde mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) plugs after root resection. Materials and Methods: This in vitro study was conducted on 170 extracted human maxillary anterior teeth. The teeth were randomly divided three experimental (n = 50) and control (n = 20) groups. In Group 1, after root canal treatment, half of the roots were cut with a bur, and the other half with an ultrasonic cutter. In Groups 2 and 3, after the 4-mm CEM and MTA plugs were placed and set, the root ends of half of the samples were cut with a bur and the other half by an ultrasonic cutter. The prevalence of cracks in the dentin and orthograde apical plugs of MTA and CEM was then assessed by scanning electron microscopy. Data were analyzed using the McNemar's, Chi-square, and Fisher's exact tests at P ≤ 0.05 level of significance. Results: In general, the prevalence of crack in dentin in Groups 2 and 3 was significantly higher than in the plug (P < 0.05). There was no significant difference in the prevalence of dentin crack in the studied groups (P > 0.05). The prevalence of crack in dentin was lower when the bur was used to cut off the end of the root, although the difference was not significant. The prevalence of crack in the plug was similar in CEM and MTA. Conclusion: Based on the results of this study, the prevalence of crack in dentin is always significantly higher than its prevalence in the plug, and the prevalence of crack in the plug was similar in CEM and MTA; then, when there is an orthograde access to the root canal and surgery is likely in future, MTA and CEM can be placed in an orthograde technique and it just resects the root during surgery.

Abstract This study was conducted to compare fracture patterns and operation times after sagittal split osteotomy (SSO) by Hunsuck/Epker approach, performed using a burr or ultrasonic device, with and without osteotomy modification. A total of 80 SSOs were performed in fresh human cadavers using a burr or ultrasonic device to investigate the influence of surgical instruments as well as an additional bone cut on the inferior border of the mandible in terms of lingual fracture patterns. The times required for osteotomy and sagittal split were measured, and postoperative cone beam computed tomography images of all splits were analyzed. Without an additional inferior osteotomy, preferred splits according to Hunsuck/Epker were achieved in 35% of cases (7/20) with the burr and 45% (9/20) with the ultrasonic instrument. The inferior modification resulted in a greater number of unwanted fracture patterns in both groups. There was no relationship between the split technique and the fracture pattern (P = 0.7854). Statistically significant differences in osteotomy time were observed between burr osteotomy and modified burr osteotomy (P = 0.006), as well as modified ultrasonic osteotomy (P < 0.001), but not between burr and ultrasonic surgery both without the inferior cut (P = 0.36). The bone cut on the inferior border did not improve split control, but rather increased the risk of unwanted fractures and extended the operation time. [ABSTRACT FROM AUTHOR]

Objective Piezoelectric surgery represents an innovative technique to perform safe and effective osteotomies and is an alternative to traditional bony tissue management using rotating or perforating instruments. We evaluated the safety and feasibility of craniotomies using an ultrasonic device that allows the selective cut of mineralized structures, avoiding damages to the vascular, dural, and parenchymal structures. Methods We analyzed a series of 300 patients (age range, 1–81 years; SD ± 15.2) who underwent elective cranial surgery for brain tumors, in which the craniotomy was performed using a piezoelectric device. Pre- and postoperative imaging, clinical notes, and intraoperative details were collected. Results There were 197 patients (66%) who underwent surgery for supratentorial tumors; the remaining 103 patients (34%) underwent surgery for infratentorial ones. Tumors involved the skull base in 125 cases. Meningiomas, gliomas, and schwannomas represented the most common histotypes. Duraplasty for dural damages was not necessary in all cases; no venous sinuses or parenchymal injuries were reported during bone work. We noted in 13 cases (4.3%) a minor dural tear, requiring only direct sutures. Bone flaps were always intact after craniotomy. No subgaleal cerebrospinal fluid (CSF) collection or CSF leak was recorded. Because of the minimal bone gap, we always achieved correct bone flap ossification. No reabsorption or mobilization of bone flap was noted. Conclusions We illustrate the feasibility and safety of a piezosurgical cutter to perform craniotomies. This alternative technique appears to be safe, with excellent cosmetic effects, adding another tool to the neurosurgical armamentarium. [ABSTRACT FROM AUTHOR]

Purpose: in vitro study of ultrasound dissection devices' impact on meniscus and knee cartilage as well as comparison of outcomes with familiar arthroscopic techniques.Materials and methods. Meniscus and joint cartilage specimen obtained during total knee replacement were placed in a normal saline. All experiments were conducted no later than in 2 hours after obtaining and followed by histology of biopsy specimens. In the first series of experiment the authors performed meniscus dissection with ultrasound instrument «Scalpel», cold plasm ablator and surgical scalpel.Results. The first series of experiments demonstrated disruption of fibers orientation on meniscus rim after dissection with scalpel; necrosis depth after coblation is 0,7-0,8 mm. Ultrasound dissection devices leave necrosis depth of 0,1-0,2 mm and smooth cartilage surface. The second series of experiments proved that after shaver application cartilage surface was coarse; certain necrosis sections of 16-90 nm were observed on relatively smooth cartilage surface after coblation. Application of ultrasound «Miller» device leaves smooth cartilage surface with no fibers, no signs of cartilage thinning and necrosis not exceeding 15 nm.Conclusion. The results of experiments confirm that use of low frequency ultrasound dissection devices is advantageous as compared to mechanical and ablation cutting techniques while ensuring histologically proven atraumatic handling of biopsy specimens of meniscus and hyaline cartilage.

The aim of this study was to evaluate if the stability of dental implants varies between dental implants placed by piezosurgery compared with those placed by conventional drilling. An electronic search in MEDLINE, SCOPUS, and the Cochrane Library was undertaken until August 2016 and was supplemented by manual searches and by unpublished studies at OpenGray. Only randomized controlled clinical trials that reported implant site preparation with piezosurgery and with conventional drilling were considered eligible for inclusion in this review. Meta-analyses were performed to evaluate the impact of piezosurgery on implant stability. Of 456 references electronically retrieved, 3 were included in the qualitative analysis and quantitative synthesis. The pooled estimates suggest that there is no significant difference between piezosurgery and conventional drilling at baseline (weighted mean differences [WMD]: 2.20; 95% confidence interval [CI]: −5.09, 9.49; P =.55). At 90 days, the pooled estimates revealed a statistically significant difference (WMD: 3.63; 95% CI: 0.58, 6.67, P =.02) favoring piezosurgery. Implant stability may be slightly improved when osteotomy is performed by a piezoelectric device. More randomized controlled clinical trials are needed to confirm these findings. [ABSTRACT FROM AUTHOR]

A noninvasive ultrasound surgery method that relies on using multi-element focused phased arrays is being successfully used to destroy tumors and perform neurosurgical operations in deep structures of the human brain. However, several drawbacks that limit the possibilities of the existing systems in their clinical use have been revealed: a large size of the hemispherical array, impossibility of its mechanical movement relative to the patient's head, limited volume of dynamic focusing around the center of curvature of the array, and side effect of overheating skull. Here we evaluate the possibility of using arrays of smaller size and aperture angles to achieve shock-wave formation at the focus for thermal and mechanical ablation (histotripsy) of brain tissue taking into account current intensity limitations at the array elements. The proposed approach has potential advantages to mitigate the existing limitations and expand the possibilities of transcranial ultrasound surgery. [ABSTRACT FROM AUTHOR]

• Design, fabrication, and characterization of a planar ultrasonic surgical tool. • The planar ultrasonic scalpel effectively cut and coagulated muscle tissue. • The instrument tip geometry seems to have a major impact on cutting performance. This paper introduces a titanium-based planar ultrasonic microscalpel. The concept of silicon-based planar ultrasonic transducers has already been proven, but they are not yet suitable for clinical use due to material failure. The main objective of this work was to develop a smaller, lighter, and more cost-effective ultrasonic scalpel that could be used as an alternative or supplementary device to current surgical instruments. Various prototypes were fabricated and characterized, differing in bonding by three epoxy adhesives and two solder pastes as well as three variations in tip design. The instruments were designed to operate in the frequency range of commercial instruments and to generate a longitudinal displacement amplitude. The electro-mechanical characterization through impedance analysis and vibration measurements was complemented by an in vitro cutting trial and an acute in vivo animal experiment in comparison to commercial ultrasonic and electrosurgical devices. The operating frequency was around 40 kHz and 48 kHz depending on whether matched or unmatched operation was used. Unmatched operation turned out to be more suitable, achieving displacement amplitudes of 25.3 μm and associated velocity amplitudes of up to 7.9 m/s at an electrical power of 10.2 W. The cutting ability was demonstrated in vivo by successful dissection even under anticoagulation. The geometry of the instrument tip was found to have a major influence on cutting performance by affecting the resonance behaviour and tissue penetration. [ABSTRACT FROM AUTHOR]

Background: There is some concern that root resection may alter the surface features and crack formation of the previously set orthograde material. The aim of this in vitro study was to evaluate the crack formation in orthograde mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) plugs after root resection. Materials and Methods: This in vitro study was conducted on 170 extracted human maxillary anterior teeth. The teeth were randomly divided three experimental (n = 50) and control (n = 20) groups. In Group 1, after root canal treatment, half of the roots were cut with a bur, and the other half with an ultrasonic cutter. In Groups 2 and 3, after the 4-mm CEM and MTA plugs were placed and set, the root ends of half of the samples were cut with a bur and the other half by an ultrasonic cutter. The prevalence of cracks in the dentin and orthograde apical plugs of MTA and CEM was then assessed by scanning electron microscopy. Data were analyzed using the McNemar's, Chi-square, and Fisher's exact tests at P ≤ 0.05 level of significance. Results: In general, the prevalence of crack in dentin in Groups 2 and 3 was significantly higher than in the plug (P < 0.05). There was no significant difference in the prevalence of dentin crack in the studied groups (P > 0.05). The prevalence of crack in dentin was lower when the bur was used to cut off the end of the root, although the difference was not significant. The prevalence of crack in the plug was similar in CEM and MTA. Conclusion: Based on the results of this study, the prevalence of crack in dentin is always significantly higher than its prevalence in the plug, and the prevalence of crack in the plug was similar in CEM and MTA; then, when there is an orthograde access to the root canal and surgery is likely in future, MTA and CEM can be placed in an orthograde technique and it just resects the root during surgery. [ABSTRACT FROM AUTHOR]

Objectives To assess heat generation in osteotomies during application of sonic and ultrasonic saws compared to conventional bur. Methods Two glass-fiber isolated nickel–chromium thermocouples, connected to a recording device, were inserted into fresh bovine rib bone blocks and kept in 20 ± 0.5 °C water at determined depths of 1.5 mm (cortical layer) and 7 mm (cancellous layer) and 1.0 mm away from the planned osteotomy site. Handpieces, angulated 24–32°, were mounted in a vertical drill stand, and standardized weights were attached to their tops to exert loads of 5, 8, 15 and 20 N. Irrigation volumes of 20, 50 and 80 ml/min were used for each load. Ten repetitions were conducted using new tips each time for each test condition. The Mann–Whitney-U test was used for statistical analysis ( p < 0.05). Results Both ultrasonic and sonic osteotomies were associated with significantly lower heat generation than conventional osteotomy ( p < 0.01). Sonic osteotomy showed non-significantly lower heat generation than ultrasonic osteotomy. Generated heat never exceeded the critical limit of 47 °C in any system. Variation of load had no effect on heat generation in both bone layers for all tested systems. An increased irrigation volume resulted in lower temperatures in both cortical and cancellous bone layers during all tested osteotomies. Conclusion Although none of the systems under the conditions of the present study resulted in critical heat generation, the application of ultrasonic and sonic osteotomy systems was associated with lower heat generation compared to the conventional saw osteotomy. Copious irrigation seems to play a critical role in preventing heat generation in the osteotomy site. [ABSTRACT FROM AUTHOR]

Ultrasonic surgical devices are increasingly used in oral, craniofacial and maxillofacial surgery to cut mineralized tissue, offering the surgeon high accuracy with minimal risk to nerve and vessel tissue. Power ultrasonic devices operate in resonance, requiring their length to be a halfwavelength or multiple-half-wavelength. For bone surgery, devices based on a half-wavelength have seen considerable success, but longer multiplehalf- wavelength endoscopic devices have recently been proposed to widen the range of surgeries. To provide context for these developments, some examples of surgical procedures and the associated designs of ultrasonic cutting tips are presented. However, multiple-half-wavelength components, typical of endoscopic devices, have greater potential to exhibit nonlinear dynamic behaviours that have a highly detrimental effect on device performance. Through experimental characterization of the dynamic behaviour of endoscopic devices, it is demonstrated how geometrical features influence nonlinear dynamic responses. Period doubling, a known route to chaotic behaviour, is shown to be significantly influenced by the cutting tip shape, whereas the cutting tip has only a limited effect on Duffing-like responses, particularly the shape of the hysteresis curve, which is important for device stability. These findings underpin design, aiming to pave the way for a new generation of ultrasonic endoscopic surgical devices. [ABSTRACT FROM AUTHOR]

The aim of the present study was to compare subjective experiences using bur, ultrasonic, and sonic osteotomy systems. Ten novice (N) and 10 expert (E) practitioners performed osteotomies on bovine ribs with each system. They scored ease of handling and sense of accuracy on visual analogue scales. The duration of the osteotomy procedure and the amount of noise were recorded objectively. Learning experience was evaluated in a second run. The Mann–Whitney U -test, Wilcoxon signed rank tests, and Spearman's rank correlation coefficient were used for the statistical analyses. The sonic system was significantly slower, with the worst noise impact (92.9 dB; standard deviation (SD) 7.1). However, both user groups improved significantly in the second run (N 7.9, E 7.6). There were no significant differences in handling. The sense of accuracy was evaluated to be significantly best for the sonic system (N 8.4, E 8.4), compared to the ultrasonic system (N 7.1, E 7.1; both P = 0.043) and bur system (N 5.5, P = 0.002; E 6.0, P = 0.006). The practitioners had a promising experience with the application of the ultrasonic system and particularly with the sonic system. [ABSTRACT FROM AUTHOR]

Background Only a few reports deal with implants placed in infected postextraction sites. Purpose Survival rates of a cohort of immediate implants cases placed in acute and chronically infected sites were compared with a cohort of noninfected ones while (1) tooth extraction and osteotomy sites were prepared with a piezosurgery device and (2) ultrasonication was applied to abate the bacterial charge at infected sites. Materials and Methods Eighty-six patients received 168 immediate implants distributed into three groups: noninfected (85), acute (36), and chronically (47) infected sites. Atraumatic extraction and implant osteotomy were performed with an ultrasonic surgery device without flap elevation. All sites received the same medication and surgical protocol; infected sites were ultrasonicated during 30 seconds at 72 W. Kaplan- Meyer survival rates were calculated at 1 year. Results The 1-year survival rates of the noninfected, chronically, and acute infected groups were 98.8, 100, and 94.4%, respectively. The differences were not statistically significant. No implant was lost after loading. All teeth and roots could be extracted in one piece. Drilling at extraction sockets was uncomplicated, without skidding. Conclusions Implant survival rates might be similar in infected and noninfected sites when infected sites receive standard medical and surgical treatment and are ultrasonicated. Atraumatic tooth/root extraction and implant placement can be reliably performed with piezoelectric surgery. [ABSTRACT FROM AUTHOR]

Objective: Neuroendoscopic surgery using an ultrasonic aspirator represents a valid tool with which to perform the safe resection of deep-seated ventricular lesions, but the handling of neuroendoscopic instruments is technically challenging, requiring extensive training to achieve a steep learning curve. Simulation-based methods are increasingly used to improve surgical skills, allowing neurosurgical trainees to practice in a risk-free, reproducible environment. The authors introduce a synthetic, patient-specific simulator that enables trainees to develop skills for endoscopic ventricular tumor removal, and they evaluate the model's validity as a training instrument with regard to realism, mechanical proprieties, procedural content, and handling., Methods: The authors developed a synthetic simulator based on a patient-specific CT data set. The anatomical features were segmented, and several realistic 1:1 skull models with all relevant ventricular structures were fabricated by a 3D printer. Vascular structures and the choroid plexus were included. A tumor model, composed of polyvinyl alcohol, mimicking a soft-consistency lesion, was secured in different spots of the frontal horn and within the third ventricle. Neurosurgical trainees participating in a neuroendoscopic workshop qualitatively assessed, by means of a feedback survey, the properties of the simulator as a training model that teaches neuroendoscopic ultrasonic ventricular tumor surgery; the trainees rated 10 items according to a 5-point Likert scale., Results: Participants appreciated the model as a valid hands-on training tool for neuroendoscopic ultrasonic aspirator tumor removal, highly rating the procedural content. Furthermore, they mostly agreed on its comparably realistic anatomical and mechanical properties. By the model's first application, the authors were able to recognize possible improvement measures, such as the development of different tumor model textures and the possibility, for the user, of creating a realistic surgical skull approach and neuroendoscopic trajectory., Conclusions: A low-cost, patient-specific, reusable 3D-printed simulator for the training of neuroendoscopic ultrasonic aspirator tumor removal was successfully developed. The simulator is a useful tool for teaching neuroendoscopic techniques and provides support in the development of the required surgical skills.

This article reviews evolving and lesser known technologies for tissue cutting and their application in oral and maxillofacial surgery., (Published by Elsevier Inc.)

Background: Piezosurgery is a surgical procedure that is able to perform osteotomies by a micrometric and selective cut of the bone tissue. The objective of this investigation was to evaluate two different techniques; an ultrasonic device, and a drill approach for implant site preparation. Methods: A total of fifty patients were recruited for the randomized clinical trial to receive dental implants for fixed prosthetic restoration in the posterior mandible and were allotted to two groups. In Group A the implant site was prepared following a drilling technique, while in Group B the implant site was prepared using an ultrasonic device; moreover, the operative duration was recorded. Postoperative pain and swelling were evaluated at 1, 2, 4, and 6 days. The crestal bone resorption was measured at 3 months from implant placement by a three-dimensional tomography evaluation. Results: The findings suggest that osteotomies performed by an ultrasonic device cause less pain and swelling. On the other hand, the piezoelectric preparation was characterized by a significative increase in the operative time. No statistical differences in crestal bone resorption were evident in the two different approaches. Conclusions: According to the outcome of the study, ultrasonic implant bed preparation can be used with success in implantology and could be considered a suitable alternative to traditional drilling techniques for dental fixture placement. [ABSTRACT FROM AUTHOR]