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.

Wettability of Different Zirconia Implant Surfaces after Glycine and Erythritol Treatment.

PURPOSE: This in-vitro study aims to investigate whether the wettability of two zirconia implant disk surfaces is affected by glycine and erythritol air-polishing, using saline, bovine serum albumin, bovine thrombin, and bovine artificial blood as the testing mediums. MATERIALS AND METHODS: Zirconia disks were provided by two implant companies: SDS. (Swiss Dental Solutions, Plymouth, MA, USA) (n=6) and Patent. (Zircon Medical AG, Altendorf, Switzerland) (n=6). Surface parameters (Sa, Sz, Sdr, Ssk, Sku, and Spd) were measured to determine their initial surface roughness. Air-polishing was completed using glycine or erythritol powders using the AIRFLOW. PERIO device (Manufactured by Electro Medical Systems (EMS)). The wettability of the disk surfaces was evaluated by the contact angle analysis applied on treated and untreated disks using four wetting solutions, saline, bovine serum albumin (BSA), bovine thrombin, and bovine artificial blood. In total, 720 contact angle measurements were completed with n=30 per group. Statistical analysis was performed using the one-way analysis of variance and post-hoc Tukey HSD test. RESULTS: The results indicate SDS. has a greater wettability than Patent. before and after air-polishing. The wettability of surfaces treated with glycine was hydrophobic in some cases. Erythritol increased the surface wettability of zirconia disks compared to glycine. BSA and bovine artificial blood had lower contact angles than saline and bovine thrombin for both untreated disks. CONCLUSIONS: The initial wettability of zirconia disks differs between manufacturers, and air-polishing with erythritol powder increases the wettability of zirconia implant disks for saline, bovine serum, bovine thrombin, and bovine artificial blood.

Digitally designed and manufactured sectional custom tray for a patient with microstomia: A case report.

Microstomia presents a challenge for the patient and dental provider. This report describes a partial digital workflow for the fabrication of a mandibular complete denture for a patient with microstomia. Computer-aided design and computer-aided manufacturing technology was utilized to 3D print a sectional custom tray with a unique design. The sectional custom tray was used to make a conventional border molded impression of the edentulous arch to fabricate a flexible complete mandibular denture for a 58-year-old female patient with scleroderma and microstomia. This treatment resulted in a successful prosthetic outcome and high patient satisfaction.

Thermographic Changes During Soft Tissue Incisions with Diode Infrared Lasers.

Objective: This study aimed to demonstrate temperature changes and heat transfer patterns in soft tissues when using infrared (IR) diode lasers, utilizing thermographic techniques. Methods: Bovine tongue slices (5 mm thick) were placed between two glass slides at 11 cm from a thermographic camera. Twenty-two centimeter-long incisions were made along the soft tissue parallel to the camera capture field. Incisions were performed using the 970 and 980 nm lasers (continuous wave, 2-watt, 320 µm-thick glass initiated, and noninitiated fiber tips, 30-sec irradiation). The maximum temperature changes in oC (ΔT) and the vertical and lateral heat transfer (in mm) were recorded for 30 sec, using the thermographic images captured using the IR camera. The ΔT and the amount of lateral and vertical heat distribution were measured in 10-sec intervals for a 30-sec irradiation period. A repeated analysis of variance (ANOVA) (p < 0.05) statistical test was used to analyze the statistical differences between the average ΔT and heat transfer patterns between the initiated and noninitiated lasers. Results: The maximum ΔT for the 970 nm diode laser with initiated tips at the 30-sec mark was 17.81 ± 11.48, while the maximum ΔT for the 980 nm diode laser with initiated tips was 13.24 ± 6.90 (p = 0.041). Statistically significant differences between the vertical and horizontal heat transfer patterns were noted between the initiated and noninitiated diode lasers. The 980 nm diode laser with initiated tips proved to have statistically significant greater vertical and lateral heat transfer when compared to the 970 nm diode laser. The 970 nm diode laser with noninitiated tips proved to have a statistically significant higher heat distribution when compared to the 980 nm laser with noninitiated tips. Conclusions: Different near-IR lasers present differences in lateral heat and tissue penetration, using initiated or noninitiated fibers, and due to these differences, power settings and irradiation period must be considered to avoid risks due to overheating.

Accuracy of torque controllers on healing abutments in implant dentistry-an in vitro study.

PURPOSE: To evaluate the accuracy of three torque-control devices used on healing abutments in implant prosthodontics. MATERIALS AND METHODS: In this in vitro experiment, three torque controllers, Ankylos friction-based, Straumann spring-based, and Anthogyr pre-calibrated torque control devices were used to tighten the healing abutments of Ankylos and Straumann dental implants to a pre-determined value of 15 Ncm. A digital torque meter (DT), Cedar DID-4A, was used to assess removal torque as a surrogate for the accuracy of the torque controllers to apply a tightening force of 15 Ncm on healing abutments.  One-way analysis of variance (ANOVA) was used to identify differences between each torque controller and the digital torquemeter, a p < 0.05 was considered significant. RESULTS: The torque required to remove the healing abutments was 16.05 ± 0.66 Ncm for the Ankylos ratchet, 12.61 ± 0.90 Ncm for the Straumann ratchet, and 14.37 ± 1.08 Ncm for the Anthogyr torque-control device. Significant statistical differences were observed between Ankylos and the control digital torquemeter (p = 1.84E-8 ; F = 50.3); Anthogyr and control digital torquemeter (p = 0.01; F = 6.79); and Straumann and control digital torquemeter (p = 0.01; F = 141.15). CONCLUSION: Friction-based (Ankylos), spring-based (Straumann), and pre-calibrated (Anthogyr) torque control devices present over-torque and under-torque values when used over healing abutments of Ankylos and Straumann implant systems.

Assisted removal of metal housings from overdentures with a 445-nm diode laser: A dental technique.

A straightforward, laser-assisted method of extracting the metal housings from an overdenture by using the visible (blue) light of a high-power dental diode laser is presented. This approach produced localized softening of the acrylic resin, allowing the metal housing to be dislodged without damage. This technique minimizes damage to the metal housings during removal, is rapid and conservative, and may help reduce patient costs.

Macroscopic Evidence of Surface Changes of Dental Implants After Insertion and Removal in Dense Bone: In Vitro Study.

PURPOSE: Titanium and zirconium wear are discussed in the literature as contributing factors for mechanical complications. The purpose of this study was to evaluate if current implant designs present visible clinical evidence of surface damage after insertion and removal in dense bone and if these changes are comparable in titanium and zirconia implants. MATERIALS AND METHODS: For this experimental in vitro and pilot study, four implant systems were evaluated. Astra Tech Implants (Dentsply Sirona), Nobel Biocare Implants (Nobel Biocare), Straumann Implants (Institut Straumann), and Zeramex Implants (Dentalpoint). Six implants of each group with similar lengths (between 10 and 11 mm) and diameters (between 4.0 and 4.5 mm) were used. Protocols for implant bed preparations in dense bovine bone disks represented type II bone density. The implants were inserted and removed to evaluate the changes experienced by their surfaces using a magnification compatible with 5× magnification of the clinical setting. The presence or absence of damage and type of damage were evaluated at the coronal, middle, and apical regions at higher magnification. The Cochran Q test for binary dichotomous samples was used for statistical comparisons. RESULTS: All the groups showed surface changes; titanium implants showed abrasion at the threads' flanks, and zirconia implants showed microfractures at the tip of the threads. CONCLUSION: Due to the insertion and removal of titanium and zirconia implants in dense bone, the flanks and tips of the implant threads will develop visible surface damage.

Temporal and Permanent Changes Induced by Maxillary Sinus Lifting with Bone Grafts and Maxillary Functional Endoscopic Sinus Surgery in the Voice Characteristics-Systematic Review.

Sinus surgery procedures such as sinus lifting with bone grafting or maxillary functional endoscopy surgery (FESS) can present different complications. The aims of this systematic review are to compile the post-operatory complications of sinus elevation with bone grafting and FESS including voice changes, and to elucidate if those changes are either permanent or temporary. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were used, and the literature was exhaustively searched without time restrictions for randomized and non-randomized clinical studies, cohort studies (prospective and retrospective), and clinical case reports with ≥4 cases focused on sinus lift procedures with bone grafts and functional endoscopic maxillary sinus surgery. A total of 435 manuscripts were identified. After reading the abstracts, 101 articles were selected to be read in full. Twenty articles that fulfilled the inclusion criteria were included for analysis. Within the limitations of this systematic review, complications are frequent after sinus lifting with bone grafts and after FEES. Voice parameters are scarcely evaluated after sinus lifting with bone grafts and no voice changes are reported. The voice changes that occur after FESS include a decreased fundamental frequency, increased nasality, and nasalance, all of which are transitory.

Spectrometric Analysis of the Wear from Metallic and Ceramic Dental Implants following Insertion: An In Vitro Study.

Titanium wear is a growing area of interest within dental implantology. This study aimed to investigate titanium and zirconium wear from dental implants at the time of insertion using X-ray-fluorescence spectrometry (XRF) and an in vitro protocol utilizing artificial bovine bone plates. Five groups were analyzed using XRF-spectrometry: groups 1-4 (titanium implants) and group 5 (zirconia implants). The implants were inserted into two bone blocks held together by a vice. The blocks were separated, and the insertion sites were analyzed for titanium (Ti) and zirconium (Zr). Statistical descriptive analyses of Ti and Zr concentrations in the coronal, middle and apical bone interface were performed. A comparative analysis confirmed differences between the implant's surface stability and Ti accumulation within the insertion sites of the bone block. There was a direct relationship between implant length and the quantity of titanium found on the bone block. The data generally indicates greater quantities of titanium in the coronal thirds of the implants, and less in the apical thirds. The titanium and zirconium found in the bone samples where the group 5 implants were inserted was not of statistical significance when compared to control osteotomies. The results of this study confirm wear from metallic, but not ceramic, dental implants at the time of insertion.

Heat Accumulation in Implant Inter-Osteotomy Areas-An Experimental In Vitro Study.

To examine the influence of the distance between adjacent implant osteotomies on heat accumulation in the inter-osteotomy area, two experimental groups with 15 pairs of osteotomies in Type II polyurethane blocks were compared: 7 mm inter-osteotomy separations (Group A, n = 15) and 14 mm inter-osteotomy separations (Group B, n = 15). An infrared thermographic analysis of thermal changes in the inter-osteotomy area was completed. A one-way analysis of variance (ANOVA) and Fisher post-test were used to determine group differences. Higher temperatures were recorded in Group A at the coronal and middle levels compared to the apical level in both groups. The temperature reached max temperatures at T80s and T100s. In Group A, the threshold for thermal necrosis was exceeded. Meanwhile, Group B did not reach the threshold for thermal necrosis. Preparing adjacent implant osteotomies in dense bone with a 7 mm separation between their centers increases the temperature in the inter-osteotomy area, exceeding the threshold for bone thermal necrosis; meanwhile, increasing the distance between osteotomies reduces the thermal accumulation and the risk for thermal necrosis.

Implant and prosthetic rehabilitation of a patient with mucous membrane pemphigoid.

Mucous membrane pemphigoid (MMP) is an autoimmune condition characterized by subepithelial separation and deposition of autoantibodies and complement along the basement membrane zone. The disease results in the development of vesiculobullous lesions of the mucous membranes and skin. This report discusses the surgical treatment and management and the prosthetic implant rehabilitation of a patient with mucous membrane pemphigoid. The rationale for this treatment was to fabricate a prosthesis that was stable and did not rub against the gingival tissues and that was easily cleaned. The overdenture attachment system used provides more stability than other attachment systems while allowing the prosthesis and abutments to be easily cleaned.

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.

Argon Bioactivation of Implants Installed Simultaneously to Maxillary Sinus Lifting without Graft. An Experimental Study in Rabbits.

BACKGROUND: The treatment of the surface of titanium implants with argon plasma improved its hydrophilicity and cell adhesion, resulting in higher bone apposition on implant and graft surfaces. The spontaneous perforation over time of the sinus mucosa after sinus augmentation has been documented in experimental studies at both implants and graft particles. The aim of the present study was to evaluate the influence of plasma argon treatment of the implant surface on bone apposition and on the rate of sinus mucosa perforations. METHODS: A sinus lifting procedure was performed bilaterally in sixteen rabbits, and implants, either treated with argon plasma or left without treatment (control), were placed simultaneously without grafts. After 8 weeks, histological analyses were carried out. RESULTS: A collapse of the sinus mucosa was observed at all implants. Twenty-four out of thirty-two implants presented sinus mucosa perforations at the apex. Several perforations were also found at the threads. Thinned mucosa sites (width < 40 µm) were found around almost all implants. About 2.6-2.9 mm of the apical regions of the implant did not present signs of osseointegration and about 1.3 mm were exposed to the sinus cavity. No statistically significant differences were found between plasma and control sites. CONCLUSIONS: In conclusion, the sinus mucosa was damaged and perforated by direct contact with treated and non-treated implant surfaces. The treatment of the implant surface with argon plasma did not affect the outcomes.

Diode Laser Light Scattering and Temperature Changes Due to Anesthesia Injection in Bovine Tongue Mucosa.

Background and objective: Diode lasers are used in periodontal therapy. Parameters such as wavelength and application mode can affect the laser/tissue interactions, quality of incision, and final outcomes. This study set out to assess the temperature changes in tissue when diode lasers are used for incisions on tissues injected with local anesthetics. Materials and methods: Incisions were made on the surface of bovine tongue parallel to the tongue axis (ex vivo). The tissue was divided into three groups (lidocaine, saline, and a control group with no infiltration). Irradiation was performed with 810 and 980 nm diode lasers. Trials were further divided using noninitiated and initiated tips. A microprobe thermocouple was placed to evaluate the temperature changes. Linear mixed-model with Tukey adjustment was used to make comparisons and p < 0.05 was denoted as statistically significant. Results: The overall group comparisons reveal that the control group mean rise in temperature is lower than both the lidocaine group (p < 0.0001) and the saline group (p < 0.0001). When combining the data in and across each group, the average temperature rise that occurred for incisions made with initiated tips was significantly lower than incisions made with noninitiated tips (p < 0.0001). Combining the data of tip initiation shows that incisions made with a 980 nm laser produced lower temperature changes, than incisions made with an 810 nm laser (p < 0.0001). Conclusions: Infiltration of water-based liquids, such as local anesthetics or saline, causes an increase in tissue temperature during irradiation, especially when noninitiated tips are used. In addition, temperature significantly rises with the use of the 810 compared with the 980 nm diode laser. Therefore, to avoid photothermal damage to the tissue, the use of initiated tips is encouraged and local anesthetics in conjunction with 810 nm diode lasers should be minimized.

Thermal Transfer on Splinted Implants During Diode Laser Irradiation In Vitro.

Objective: Laser irradiation is being used for treatment of peri-implantitis. Therefore, this study aimed to assess the heat transfer from laser irradiation on an implant-supported, metal-ceramic fixed prosthesis in vitro. Materials and methods: Two titanium implants were placed in artificial type I bone, and after abutment connection, a bridge was fabricated and cemented. A peri-implant 3-wall defect was created around one of the implants. Thermocouples were placed at coronal (T1/T2) and apical (T3/T4) positions of both implants, and the T5 thermocouple was placed in the pontic. An identical setup was created in the type IV artificial bone. Diode laser irradiation (2 W, noninitiated tips, 320-µm fiber, and noncontact) was performed for 60 sec on each experimental model. This experiment was performed separately with 810- and 980-nm lasers for pulsed and continuous modes. ΔT based on the baseline was recorded during irradiation. Statistical analysis was performed with repeated analysis of variance. Results: Across all experimental models, the recorded ΔT (°) values in T2, T4, and T5 at 10, 30, and 60 sec were significantly less than 10°C (p < 0.001) for both types of bones. For both types of bones, there was a statistically significant ΔT greater than 10°C (p < 0.001) for continuous and pulsed 980-nm irradiation and continuous 810-nm diode laser irradiation after 60 sec. For both 810- and 980-nm lasers, there was a statistically significant ΔT greater than 10°C (p < 0.001) for type I and IV bones under irradiation and only for the type I bone model under pulsed irradiation after 60 sec. Conclusions: Within the limitations of this study, 810- and 980-nm lasers on splinted implants placed in vitro may increase the temperature on adjacent splinted implants due to material conductivity and splinting. Clinicians are advised to keep the temperature lower than the critical threshold following recommended power settings to avoid excessive heat and control complications due to overheating.

Macrogeometry and Bone Density Control Over the Primary Stability of 6-mm Implants: An In Vitro Study.

PURPOSE: Short implants are used in clinical conditions of insufficient vertical bone availability. This study aimed to compare the primary stability of short implants with different macrodesigns placed in different bone densities in vitro. MATERIALS AND METHODS: One hundred twenty short (6-mm) implants (20/group) were placed at the bone level in commercially available polyurethane blocks representing type I and IV bone quality. The groups were as follows: test A group (4.6-mm diameter with tapered body), test B group (4.8-mm diameter/cylindric microthreaded neck), and test C group (4.8-mm diameter, cylindric body with polished collar, three threads at the intraosseous portion). Implant primary stability was assessed using insertion torque and implant stability quotient (ISQ) values. A blinded calibrated clinician recorded all measurements. Statistical comparisons were completed using a one-way analysis of variance (ANOVA) and Bonferroni posttests. RESULTS: The insertion torque values (mean ± SD) for groups A, B, and C in type I bone were 52.50 ± 5.25, 49.00 ± 5.98, and 46.25 ± 3.93, and in type IV bone, the values were 14.00 ± 2.05, 15.50 ± 2.76, and 9.75 ± 1.11, respectively. Also, the ISQ values were 67.25 ± 2.760, 69.25 ± 1.67, and 61.80 ± 5.68 (type I bone); and 53.27 ± 1.99, 60.65 ± 2.11, and 51.97 ± 4.51 (type IV bone), respectively. The comparison showed statistical differences in ISQ (Bonferroni adjusted P < .0001) for the A and B groups but also for the A and C groups (type I bone), in soft bone between the A and B groups and between the B and C groups, and also for the insertion torque values for the A and C groups and between the B and C groups in type IV bone. CONCLUSION: Short implant macrogeometry defines primary stability. Short implants with 6-mm length and multiple threads can achieve good primary stability in vitro in type I and IV artificial bone.

Temperature Change from Diode Lasers in Oral Mucosa: An Ex Vivo Study.

Objective: The aim of this ex vivo study was to assess the mean temperature change deep in tissue during diode laser (980 vs. 810 nm) irradiation using continuous and pulsed laser and initiated versus noninitiated tips. Background data: Previous studies have determined thermal effects of diode lasers on tissue damage but have yet to compare the incision qualities of 980 versus 810 nm diode lasers. Further studies need to be done to determine the efficiency of diode lasers to create a safer protocol for clinicians. Methods: Ninety-six incisions of 20 mm length were made in three bovine tongues using diode lasers (980 and 810 nm). Both continuous and pulsed modes were tested with initiated (using blue articulating paper) and noninitiated glass fibers (n = 12 per group). Thermocouples attached to LabChart® software were used to measure mean temperature changes. Mean, standard deviations, and p values were conducted for each group to test the statistical significance (p < 0.05). Results: Quality of incisions were better using the initiated tips for both laser wavelengths. Pulsed mode with 810 nm diode laser produced the least mean temperature change in tissue. Overall, both pulsed and continuous mode showed similar thermal effects on tissue. Conclusions: Within the limitations of this study, noninitiated tips are responsible for diffuse irradiation in tissue and are associated with tissue temperature increase during surgery. Low incision quality was observed using noninitiated tips. The temperature changes seem to be dependent on the laser wavelength and are higher for 980 nm compared with 810 nm pulsed diode laser.