Cooling Efficiency of Sleeveless 3D-Printed Surgical Guides with Different Cylinder Designs.

Background and Objectives: Surgical guides might impede the flow of coolant to the implant drills during the preparation of the implant bed, potentially contributing to increased temperatures during bone drilling. The objective of this experimental study was to assess the cooling efficiency of various guiding cylinder designs for sleeveless surgical guides used in guided surgery. Materials and Methods: In this experimental study, surgical guides with three different guiding cylinder designs were printed. One group had solid cylinders (control) and two test groups (cylinders with pores and cylinders with windows). Forty customized polyurethane blocks with type III bone characteristics were fitted into the guide and fixed in a vise, and implant bed preparations were completed using a simplified drilling protocol with and without irrigation. An infrared thermographic camera was used to record the temperature changes during drilling at the coronal, middle, and apical areas. ANOVA test and Games-Howell post hoc test were used to determine significant thermal differences among groups. Results: A significant thermal increase was observed at the coronal area in the group without irrigation (39.69 ± 8.82) (p < 0.05). The lowest thermal increase was recorded at the surgical guides with windows (21.451 ± 0.703 °C) compared to solid (25.005 ± 0.586 °C) and porous surgical guides (25.630 ± 1.004) (p < 0.05). In the middle and apical areas, there were no differences between solid and porous cylinders (p > 0.05). Conclusions: 3D-printed sleeveless surgical guides with window openings at the guiding cylinders reduce the temperature elevation at the cortical bone in guided implant surgery.

Counterclockwise Drilling with Different Tapered Drills Condenses the Implant Bed-An Optical Coherence Tomography In Vitro Study.

Background and Objectives: To evaluate the condensation and the microarchitecture of implant bed walls of sites prepared with counterclockwise drilling with tapered implant drills using optical coherence tomography. Materials and Methods: Four drill designs with different wall and tip angles were used. Polyurethane laminas resembling type IV bone microarchitecture were superimposed and clamped with a vice to simulate the coronal, middle, and apical aspects of the implant site. Twenty implant beds were prepared at 1200 rpm in clockwise (control) and counterclockwise (test) directions (N = 160). Optical coherence tomography (OCT) was used to evaluate the condensation and microarchitecture characteristics of the implant bed walls. The relative condensation was calculated using the Image J software Bone application. The microarchitecture was evaluated in reconstructed 3D volumes in XY, XZ, and YZ sections. Statistical analysis was performed using one-way ANOVA. Dunnet test was applied to determine differences between groups. Significance was set as p < 0.05. Results: Counterclockwise drilling (Test) condensed and changed the microarchitecture of the apical regions for all the implant beds in all of the groups when compared to clockwise drilling (control). The apical region of test groups showed the highest relative bone condensation (p = 0.026) when compared to controls. Conclusions: The direction of rotation (counterclockwise drilling) and not the design of tapered drills (tip and wall angles) is responsible for the condensation at the apical area observed in polyurethane blocks. The OCT method can be used for the evaluation of changes in density and microstructure of polyurethane blocks.

Comparative evaluation of crestal bone levels following placement of implant in delayed implant bed: An in vivo clinical study.

BACKGROUND: Restoring lost dentition using dental implant is one of the most promising treatment modality, for both complete and partially dentulous situation. In order to have more predictable outcome, the quest for coming up with a surgical protocol has been never ending. Keeping the same in mind the present study was conducted to place implant in delayed implants beds, i.e., 14 days after the osteotomy site was prepared. MATERIALS AND METHODS: For the purpose of the study, ten implants measuring 4.2 mm × 10 mm were placed in ten healthy individuals with missing mandibular first molars in site prepared 14 days before actual placement of implants, i.e., delayed implant beds. RESULTS: The study revealed that, on evaluation of the bone levels at the time of placement of prosthetic loading revealed, a bone gain was maximum after 3 months of prosthetic loading. CONCLUSION: A significant bone gain with a mean of 0.8 mm makes this technique of placing implants in delayed implant beds a more predictable technique than conventional protocol.

Ultrasonic vs Drill Implant Site Preparation: Post-Operative Pain Measurement Through VAS, Swelling and Crestal Bone Remodeling: A Randomized Clinical Study.

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.

Sub-crestal positioning of implants results in higher bony crest resorption: an experimental study in dogs.

OBJECTIVE: To compare peri-implant soft- and hard-tissue integration at implants installed juxta- or sub-crestally. Furthermore, differences in the hard and soft peri-implant tissue dimensions at sites prepared with drills or sonic instruments were to be evaluated. MATERIAL AND METHODS: Three months after tooth extraction in six dogs, recipient sites were prepared in both sides of the mandible using conventional drills or a sonic device (Sonosurgery(®)). Two implants with a 1.7-mm high-polished neck were installed, one with the rough/smooth surface interface placed at the level of the buccal bony crest (control) and the second placed 1.3 mm deeper (test). After 8 weeks of non-submerged healing, biopsies were harvested and ground sections prepared for histological evaluation. RESULTS: The buccal distances between the abutment/fixture junction (AF) and the most coronal level of osseointegration (B) were 1.6 ± 0.6 and 2.4 ± 0.4 mm; between AF and the top of the bony crest (C), they were 1.4 ± 0.4 and 2.2 ± 0.2 mm at the test and control sites, respectively. The top of the peri-implant mucosa (PM) was located more coronally at the test (1.2 ± 0.6 mm) compared to the control sites (0.6 ± 0.5 mm). However, when the original position of the bony crest was taken into account, a higher bone loss and a more apical position of the peri-implant mucosa resulted at the test sites. CONCLUSIONS: The placement of implants into a sub-crestal location resulted in a higher vertical buccal bone resorption and a more apical position of the peri-implant mucosa in relation to the level of the bony crest at implant installation. Moreover, peri-implant hard-tissue dimensions were similar at sites prepared with either drills or Sonosurgery(®).