Dynamic Navigation in Dental Implantology: The Influence of Surgical Experience on Implant Placement Accuracy and Operating Time. An in Vitro Study.

AIM: the aim of this in vitro study was to test whether the implant placement accuracy and the operating time can be influenced by the operator's experience. MATERIALS AND METHODS: sixteen models underwent a (Cone Beam Computer Tomography) CBCT and implant positioning was digitally planned on this. The models were randomly assigned to four operators with different levels of surgical experience. One hundred and twelve implant sites were drilled using a dynamic navigation system and operating times were measured. Based on postoperative CBCTs, dental implants were virtually inserted and superimposed over the planned ones. Two-dimensional and 3D deviations between planned and virtually inserted implants were measured at the entry point and at the apical point. Angular and vertical errors were also calculated. RESULTS: considering coronal and apical 3D deviations, no statistically significant differences were found between the four operators (p = 0.27; p = 0.06). Some vectorial components of the deviation at the apical point and the angular errors of some operators differed from each other. CONCLUSIONS: within the limitations of this study, dynamic navigation can be considered a reliable technique both for experienced and novice clinicians.

Mechanical testing of antimicrobial biocomposite coating on metallic medical implants as drug delivery system.

Post-operative infection often occurs following orthopedic and dental implant placement requiring systemically administered antibiotics. However, this does not provide long-term protection. Over the last few decades, alternative methods involving slow drug delivery systems based on biodegradable poly-lactic acid and antibiotic loaded hydroxyapatite microspheres were developed to prevent post-operative infection. In this study, thermally anodised and untreated Ti6Al4V discs were coated with Poly-Lactic Acid (PLA) containing Gentamicin (Gm) antibiotic-loaded coralline Hydroxyapatite (HAp) are investigated. Following chemical characterization, mechanical properties of the coated samples were measured using nanoindentation and scratch tests to determine the elastic modulus, hardness and bonding adhesion between film and substrate. It was found that PLA biocomposite multilayered films were around 400nm thick and the influence and effect of the substrate were clearly observed during the nanoindentation studies with heavier loads. Scratch tests of PLA coated samples conducted at ~160nm depth showed the minimal difference in the measured friction between Gm and non Gm containing films. It is also observed that the hardness values of PLA film coated anodised samples ranged from 0.45 to 1.9GPa (dependent on the applied loads) against untreated coated samples which ranged from 0.28 to 0.8GPa.

Augmented reality for dental implantology: a pilot clinical report of two cases.

BACKGROUND: Despite the limited number of articles dedicated to its use, augmented reality (AR) is an emerging technology that has shown to have increasing applications in multiple different medical sectors. These include, but are not limited to, the Maxillo-facial and Dentistry disciplines of medicine. In these medical specialties, the focus of AR technology is to achieve a more visible surgical field during an operation. Currently, this goal is brought about by an accurate display of either static or dynamic diagnostic images via the use of a visor or specific glasses. The objective of this study is to evaluate the feasibility of using a virtual display for dynamic navigation via AR. The secondary outcome is to evaluate if the use of this technology could affect the accuracy of dynamic navigation. CASE PRESENTATION: Two patients, both needing implant rehabilitation in the upper premolar area, were treated with flapless surgery. Prior to the procedure itself, the position of the implant was virtually planned and placed for each of the patients using their previous scans. This placement preparation contributed to a dynamic navigation system that was displayed on AR glasses. This, in turn, allowed for the use of a computer-aided/image-guided procedure to occur. Dedicated software for surface superimposition was then used to match the planned position of the implant and the real one obtained from the postoperative scan. Accuracies, using this procedure were evaluated by way of measuring the deviation between real and planned positions of the implants. For both surgeries it was possible to proceed using the AR technology as planned. The deviations for the first implant were 0.53 mm at the entry point and 0.50 mm at the apical point and for the second implant were 0.46 mm at the entry point and 0.48 mm at the apical point. The angular deviations were respectively 3.05° and 2.19°. CONCLUSIONS: From the results of this pilot study, it seems that AR can be useful in dental implantology for displaying dynamic navigation systems. While this technology did not seem to noticeably affect the accuracy of the procedure, specific software applications should further optimize the results.

Dynamic navigation: a prospective clinical trial to evaluate the accuracy of implant placement.

AIM: The objective of this prospective pilot clinical study was to evaluate the accuracy of a new dynamic navigation system and postoperative clinical outcomes. MATERIALS AND METHODS: Ten patients were recruited and 18 implants were placed. The surgery was performed with the navigation system and according to the virtual planning. Ten implants were placed using a flapless technique and eight implant sites were prepared with a combined piezo-drill method. The deviation between the real implant position obtained from the postoperative cone beam computed tomography (CBCT) scan and the planned implant position was measured. RESULT: The average deviation was 1.19 ± 0.54 mm. The mean deviation measured at the insertion point was 1.04 ± 0.47 mm and at the apical point it was 1.35 ± 0.56 mm. The depth error was 0.43 ± 0.34 mm. The axis deviation was 6.46 ± 3.95 degrees. No significant differences were found between the flapless and the open-flap approaches and between the conventional and piezoelectric techniques. No complications occurred. CONCLUSION: The accuracy values reported in this study are comparable, although not superior, to the literature data regarding dynamic and static computer-guided surgery. Dynamic navigation could increase the quality and safety of interventions and may reduce morbidity when compared with freehand insertion techniques. Deviation at the entry point (mm) Deviation at the apex (mm) Depth deviation (mm) Angular deviation (degrees) Mean 1.04 1.35 0.43 6.46 SD 0.47 0.56 0.34 3.95 Maximum 2.21 2.28 1.41 6.46 Minimum 0.45 0.59 0.03 3.95 Deviation at the entry point (mm)Deviation at the apex (mm)Depth deviation (mm)Angular deviation (degrees)OF0.96 ± 0.331.45 ± 0.600.35 ± 0.227.93 ± 5.15FL1.10 ± 0.581.27 ± 0.570.49 ± 0.425.28 ± 2.60Data are shown as mean ± SDOF = open-flap surgery; FL = flapless surgery Deviation at the entry point (mm)Deviation at the apex (mm)Depth deviation (mm)Angular deviation (degrees)P1.01 ± 0.251.37 ± 0.480.44 ± 0.267.63 ± 4.30C1.06 ± 0.621.34 ± 0.660.42 ± 0.415.52 ± 3.81Data are shown as mean ± SDP = piezoelectric tips; C = conventional burs.

Simplifying Zygomatic Implant Site Preparation Using Ultrasonic Navigation: A Technical Note.

Zygomatic implant site preparation could be considered a challenging procedure because of the use of a very long twist drill that could sometimes be difficult to control due to the need for drilling the malar bone on an oblique surface. Ultrasound was recently suggested to achieve better control, but the specific long tips required are not readily available, and the elongated tip also tends to reduce the efficacy. This technical note describes a proposal of a novel computer-aided technique to simplify the procedure of zygomatic implant site preparation. This method uses a standard-length ultrasonic tip to prepare the crestal bone and the zygomatic bone in two individual steps. The desired implant trajectory can be achieved during preparation using a real-time tracking navigation system. The combined use of the navigation system and the ultrasonic tips could aid the surgeon, during the first steps, in achieving optimal control of the instruments employed for the implant site preparation and keeping the planned zygomatic implant position. If the efficacy of the procedure is confirmed through clinical trials, this technique could also contribute to reducing the invasiveness of the procedure, promoting a smaller flap, and reducing the soft tissue damage.

Three-Dimensional Implant Positioning with a Piezosurgery Implant Site Preparation Technique and an Intraoral Surgical Navigation System: Case Report.

This case report describes new implant site preparation techniques joining the benefits of using an intraoral navigation system to optimize three-dimensional implant site positioning in combination with an ultrasonic osteotomy. A report of five patients is presented, and the implant positions as planned in the navigation software with the postoperative scan image were compared. The preliminary results are useful, although further clinical studies with larger populations are needed to confirm these findings.

Biomechanics and functional distortion of the human mandible.

The reaction to the use of finite element analysis (FEA) in the study of the human body has been particularly enthusiastic. Of equal and challenging complexity is the investigation of load/stress distribution and morphological distortion of the human mandible under functional loads. Furthermore, the mandible also impacts directly on body function and esthetics, playing a vital role, such as mastication and speech. The application of FEA to the biomechanical investigation of the oral systems, such as human teeth and mandibular bone remodeling, began in the early 1970s. The clinical significance of jaw deformation is unknown. The primary concern is that deformation might result in an ill-fitting superstructure or the creation of harmful strains in the patient-implant complex. Although mandibular implant treatment has a high success rate, the possibility of failure caused by these dimensional changes and the related micromotion cannot be ignored.