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.

Management of Advanced Peri-Implantitis by Guided Bone Regeneration in Combination with Trabecular Metal Fixtures, Two Months after Removal of the Failed Implants: Two-Year Results of a Single-Cohort Clinical Study.

Background: Implant replacement is among the treatment options for severe peri-implantitis. The aim of this single-cohort study was to evaluate the feasibility of replacing compromised implants affected by advanced peri-implantitis with new implants with a porous trabecular metal (TM) structure. Materials and Methods: Patients with one or more implants in the posterior region showing a defect depth >50% of implant length, measured from the residual crest, were consecutively included. Two months after implant removal, patients received a TM implant combined with a xenograft and a resorbable membrane. The implant stability quotient (ISQ) was measured at placement and re-assessed five months later (at uncovering), then after 6, 12, and 24 months of function. Marginal bone loss was radiographically evaluated. Results: Twenty consecutive cases were included. One patient dropped out due to COVID-19 infection, and nineteen cases were evaluated up to 24 months. At placement, the mean ISQ was 53.08 ± 13.65 (standard deviation), which increased significantly to 69.74 ± 9.01 after five months of healing (p < 0.001) and to 78.00 ± 7.29 after six months of loading (p < 0.001). Thereafter, the ISQ remained stable for up to 24 months (80.55 ± 4.73). All implants successfully osseointegrated and were restored as planned. After two years, the average marginal bone level change was -0.41 ± 0.38 mm (95% confidence interval -0.60, -0.21), which was limited yet significantly different from the baseline (p < 0.05). Conclusions: The treatment of advanced peri-implant defects using TM implants inserted two months after explantation in combination with guided bone regeneration may achieve successful outcomes up to two years follow-up, even in the presence of low primary stability.

Understanding Dental Lasers: They're Not Only for Frenectomies.

Often, clinicians consider lasers in dentistry only as a tool for doing frenectomies. Unfortunately, despite the dental laser having more than 30 years of clinical application, many practitioners and educators may lack an extensive understanding of this valuable instrument. This article highlights the scientific basis and indications for the use of lasers in dentistry.

Impact of two different patient decision aids in prosthodontic consultations: a prospective randomized controlled study.

OBJECTIVES: Different approaches to prosthodontic consultation, all involving a strong focus on shared decision-making, were analyzed from the perspective of patients by inter-group comparisons. No patient decision aid (PDA) was used in the control group, a paper-based PDA in test group 1, and a software-based PDA in test group 2. MATERIALS AND METHODS: Seventy-five patients were prospectively randomized to the control group or a test group. All patients then rated the consultation on a questionnaire, six key items of which were analyzed, along with the time spent on each consultation. RESULTS: Overall satisfaction was highest in test group 2, with a significant difference from the control group (p = 0.015). Test group 2 showed the most favorable ratings for all six questionnaire items, which invariably was significant compared to the control group (p = 0.032). Test group 1 significantly differed from test group 2 based on two items (consultation was adequately intelligible: p = 0.011; consultation was adequately comprehensive: p = 0.034) but not from the control group based on any item (p = 0.070). CONCLUSIONS: Within the limitations of this study, the use of a software-based PDA, in particular, can be recommended based on patient satisfaction and was associated with the shortest sessions for consultation. CLINICAL RELEVANCE: Patients are routinely faced with a wealth of information in dental offices and may be overwhelmed especially by prosthetic treatment options and decision requirements. Our findings shed some light on the nature of aids that may truly be helpful in the process of shared decision-making. TRIAL REGISTRATION: ClinicalTrials.gov.Identifier: ISRCTN11472465.

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.

Neurological Risks During Implant Placement in the Anterior Maxilla and Mandible: A Literature Review.

The placement of implants in the anterior maxillary and mandibular region requires esthetic proficiency and surgical finesse. It is important to consider the esthetic outcome while avoiding any type of nerve injury for the patient. In this literature review, anatomical structures of the anterior jaw were reviewed from a gross anatomical and radiographic interpretation. A discussion on the frequency of neurosensory complications for patients as a result of nerve damage in this region was evaluated. The purpose of this literature review was to educate the dental surgeon to consider the anterior jaw's neurological structures when performing procedures like implant surgery. The mandibular incisive canal (MIC) presents as an extension of the inferior alveolar canal that runs between the mental foramina. The MIC is a structure that is easily depicted in cone-beam computed tomography (CBCT) imaging and is present in most subjects in gross anatomical studies. The anterior loop of the mental nerve is another structure that is discussed in this paper. Although its structure is accurately depicted in CBCT images, its anatomical variations in patients can make implant treatment planning difficult. The maxilla contains 2 neurovascular structures that were discussed. First, the nasopalatine canal and its relation and impact on implant placement is evaluated. Case reports are reviewed that outline a prophylactic enucleation and bone grafting of the canal prior to implant placement. Second, the canalis sinuosus, which houses the anterior superior alveolar nerve, is of concern during implant placement in the lateral incisor region. Case reports involving nerve damage with follow-up are discussed.

Thermal Effects of 445-nm Diode Laser Irradiation on Titanium and Ceramic Implants.

This study aimed to evaluate temperature changes in titanium and ceramic implants after using a 445-nm diode laser under different in vitro conditions. Titanium (Ti) and ceramic (Zr) dental implants were placed into a bone analog, and an intrabony defect was created at each implant. A 445-nm diode laser was used to irradiate the defects for 30 seconds, noncontact, at 2 W in continuous wave (c.w.) and pulsed mode. The experiment was done at room temperature (21.0 ± 1°C) and in a water bath (37.0 ± 1°C). Two thermocouple probes were used to record real-time temperature changes (°C) at the coronal part of the implant (Tc) and the apex (Ta). The temperature was recorded at time 0 (To) and after 30 seconds of irradiation (Tf). The average temperature change was calculated, and a descriptive analysis was conducted (P < .05). The Ti implant resulted in the highest ΔT values coronally (29.6°C) and apically (6.7°C) using continuous wave at 21°C. The Zr implant increased to 26.4°C coronally and 5.2°C apically. In the water bath, the coronal portion of the Ti and Zr implants rose to 14.2°C and 14.01°C, respectively, using continuous waves. The ΔT values for Ti were 11.9°C coronally and 1.7°C apically when placed in a water bath using pulsed mode. The lowest ΔT occurred on the Zr implant with ΔTc and ΔTa of 4.8°C and 0.78°C, respectively. Under in vitro conditions, the 445-nm diode laser in pulsed mode seems to be safe for use on ceramic implants and should be used with caution on titanium implants.

Dental Diode Lasers for Implant Uncovering: A Case Series.

Diode lasers are increasingly being utilized as an alternative to conventional soft tissue surgery. Diode lasers originally referred to wavelengths ranging from 810 to 980 nm, but a visible diode laser with a 445-nm wavelength has emerged as an additional wavelength for soft tissue surgery. The goal of this case series was to demonstrate the clinical results of both visible and near-infrared (NIR) wavelengths when utilized for stage-two implant surgery. Ten patients with 23 implants were treated at Stony Brook University, Department of Periodontology, for implant uncovering using both visible and nonvisible (NIR) diode lasers. The uncovering was performed utilizing 445-, 970-, and 980-nm wavelengths at a power setting of 2 W in either continuous or pulsed modes. The fiberoptic tips were initiated using blue articulating paper. Either topical benzocaine or infiltration anesthesia was utilized prior to soft tissue removal with the initiated tip. All patients healed uneventfully without any postoperative complications. Visible and NIR diode lasers provide an alternative and safe method to uncover submerged implants at stage-two surgery.

Hypercementosis in Late Pleistocene Homo sapiens fossils from Klasies River Main Site, South Africa.

OBJECTIVE: To examine early Homo sapiens fossils from the Late Pleistocene site of Klasies River Main Site, South Africa for evidence of hypercementosis. The specimens represent seven adult individuals dated to between 119,000 and 58,000 years ago. These observations are contextualized in relation to the incidences of hypercementosis among recent human populations and fossil human samples and the potential etiologies of hypercementosis. DESIGN: The fossils were investigated utilizing micro-CT and nano-CT scanning to visualize and measure cementum apposition on permanent incisor, premolar and molar roots. Cementum thickness was measured at mid-root level, and the volume of the cementum sleeve was calculated for the two fossil specimens that display marked hypercementosis. RESULTS: Two of the fossils display no evidence of cementum hypertrophy. Three exhibit moderate cementum thickening, barely attaining the quantitative threshold for hypercementosis. Two evince marked hypercementosis. One of the Klasies specimens with marked hypercementosis is judged to be an older individual with periapical abscessing. The second specimen is a younger adult, and seemingly similar in age to other Klasies fossils that exhibit only minimal cementum apposition. However, this second specimen exhibits dento-alveolar ankylosis of the premolar and molars. CONCLUSIONS: These two fossils from Klasies River Main Site provide the earliest manifestation of hypercementosis in Homo sapiens.

Verhoeff van Gieson staining in laser-irradiated gingival tissues.

There have been several studies on the use of the Verhoeff van Gieson staining method to demonstrate thermal effects on tissues. However, this method has rarely been used for the analysis of periodontal tissues. This study was undertaken to compare the quality and effectiveness of the Verhoeff van Gieson (VVG) staining method with conventional hematoxylin & eosin (H&E) in measuring the thermal effects in gingival tissues. Periodontal tissues around bovine mandibular teeth were treated using different surgical lasers (wavelengths of 10,600 nm, 970 nm, and 445 nm) at 2 W power setting. Measurements of the depth of the coagulation zone were recorded for all treatment groups in sample tissues stained with H&E as well as the VVG-staining method. Measures were interpreted by a trained pathologist. A statistical analysis was performed using the Wilcoxon signed-rank test to determine if there was a statistically significant difference between values recorded for the light penetration depth on tissues stained with each of the two staining methods. It was determined that there was no significant difference in the recorded values (P = 0.23). We have concluded that the VVG-stained tissues were better able to visualize the depth of thermal damage and thus may make it easier for someone not well trained to interpret the depth of light penetration in these tissues.

The Significance of Mylohyoid Muscle Release (MMR) in the Vertical and Horizontal Ridge Augmentation Surgeries; Clinical and Human Cadaver Analyses of the Techniques.

(1) Background: Ridge augmentations either horizontal (HRA) or vertical (VRA) in the posterior mandible are very challenging regenerative procedures. To attain and retain tension-free primary closure, buccal periosteal and mylohyoid muscle releases should be performed. The purpose of the present study was to review, analyze and discuss the three different techniques for the mylohyoid muscle release (MMR) in VRA and HRA surgeries on a clinical and human cadaver level. (2) Presentation of the techniques: Three different techniques are described in the literature regarding the lingual flap management: (i) the finger sweep technique (FST), (ii) the release of the mylohyoid muscle attachment on the lingual flap (MMALF), and (iii) the mylohyoid preservation technique (MPT) in three key anatomical zones. All three techniques, even though they use a different approach, can achieve similar amount of horizontal and vertical mylohyoid muscle release although MPT showed statistically significant higher flap advancement. The human cadaver analyses revealed that all three techniques are considered safe since they do not approximate vital anatomical structures. (3) Conclusions: All three techniques are considered safe, but they are not free of limitations or complications; therefore, they should be performed only by highly experienced and trained clinicians. MPT achieved statistically significant higher flap advancement.

A 23-Year Observational Follow-Up Clinical Evaluation of Direct Posterior Composite Restorations.

The purpose of this observational follow-up clinical study was to observe the quality of posterior composite restorations more than 23 years after application. A total of 22 patients, 13 male and 9 female (mean age 66.1 years, range 50-84), with a total of 42 restorations attended the first and second follow-up examinations. The restorations were examined by one operator using modified FDI criteria. Statistical analysis was performed with the Wilcoxon Mann-Whitney U test and Wilcoxon exact matched-pairs test with a significance level of p = 0.05. Bonferroni-Holm with an adjusted significance level of alpha = 0.05 was applied. With the exception of approximal anatomical form, significantly worse scores were seen for six out of seven criteria at the second follow-up evaluation. There was no significant difference in the first and second follow-up evaluations in the grades of the restorations with regard to having been placed in the maxilla or mandible, as well as for one-surface or multiple-surface restorations. The approximal anatomical form showed significantly worse grades at the second follow-up when having been placed in molars. In conclusion, the study results show that significant differences regarding FDI criteria in posterior composite restorations occur after more than 23 years of service. Further studies with extended follow-up time and at regular and short time intervals are recommended.

Tissue-Level Laser-Lok Implants Placed with a Flapless Technique: A 4-Year Clinical Study.

BACKGROUND: The present study aims to analyze the use of Laser-Lok microtextured neck implants placed with a transmucosal surgical approach. The marginal bone level (MBL) and periodontal parameters were evaluated in a cohort prospective 4-year clinical study. METHODS: A total of 41 implants were placed in 36 healthy consecutive patients (16 males, 20 females, mean age 60 ± 9 years). Tapered tissue level implants, characterized by a 2.0 mm laser-microtextured neck, were used with a flapless approach. Customized abutments and provisional resin crowns were positioned. Definitive metal-ceramic crowns were cemented approximately 4 months after insertion. Periapical radiographs were taken after 1, 3, 6, 12, 36 and 48 months from implant placement to evaluate MBL. Gingival thickness (thin/thick), plaque score (PS) and bleeding on probing (BoP) were evaluated. RESULTS: After 48 months, all implants were safe from complications. No complications, peri-implantitis, early implant failures or mucositis occurred. The survival rate was 100%. Mean MBL during the follow-up was -0.15 ± 0.18 at T1, -0.29 ± 0.29 at T3, -0.45 ± 0.37 at T6, -0.53 ± 0.45 at T12, -1.06 ± 1.13 at T 36 and -1.10 ± 0.89 at T 48. Implants placed 2-3 months after tooth extraction revealed lower MBL variation when compared to those placed immediately (in fresh extraction sockets) or in completely healed ridges (delayed group). Narrower diameter implants (3.8 mm) showed significantly higher MBL variation when compared to 4.6 diameter implants. Multilevel analysis at T48 revealed that among all the evaluated variables, implant diameter was the factor mostly associated with MBL modifications (p = 0.027). CONCLUSION: This 4-year clinical study supports the use of Laser-Lok implants placed at tissue level with a flapless approach. A limited bone loss during the 48-month follow-up was observed. Periodontal parameters were stable with no sign of inflammation or soft tissue alteration. The use of Laser-Lok implants with transmucosal surgery represents a suitable technique with a minimally invasive approach.

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.

Clinical Outcomes of Metal-Ceramic versus Metal-Acrylic Resin Implant-Supported Fixed Complete Dental Prostheses: A Systematic Review and Meta-analysis.

PURPOSE: To compare the clinical outcomes of metal-ceramic vs metal-acrylic resin implant-supported fixed complete denture prostheses (IFCDPs). MATERIALS AND METHODS: An electronic literature database search was conducted in the CINAHL, EMBASE, PubMed, and Web of Science databases. Additionally, a manual search of the literature was performed. Studies conducted in edentulous human subjects comparing clinical outcomes of metal-acrylic resin IFCDPs to those of metal-ceramic IFCDPs were included if quantitative outcomes for the following variables were reported: implant failure, prosthetic failure, incidence of peri-implantitis, incidence of peri-implant mucositis, incidence of peri-implant mucosal recession, prosthetic complications, and any patient-centered outcomes. Data from included studies were pooled to estimate effect size. RESULTS: Five studies met the inclusion criteria. A quantitative analysis was possible for risk of implant failure, prosthesis failure, and incidence of peri-implantitis. Meta-analysis showed no statistically significant differences in the risk of implant or prosthesis failure between the two groups. However, meta-analysis showed a significantly greater risk of developing peri-implantitis at the implant level in the metal-acrylic group when compared to the metal-ceramic group (risk difference = 0.069; 95% CI = 0.028 to 0.06; P = .001; fixed-effects model). Furthermore, descriptive analysis of the literature indicated a higher incidence of other biologic complications such as peri-implant mucositis and peri-implant mucosal recession, as well as prosthetic complications such as abrasion and veneer fracture, in metal-acrylic resin IFCDPs compared to metal-ceramic IFCDPs. CONCLUSION: The available evidence suggests that a higher incidence of biologic and prosthetic complications, including a higher risk of peri-implantitis, are present with metal-acrylic resin IFCDPs compared to metal-ceramic IFCDPs.

Mesh Ridge Augmentation Using CAD/ CAM Technology for Design and Printing: Two Case Reports.

The use of guided bone regeneration to achieve a stable peri-implant bone foundation has been shown to be a highly predictable and successful treatment in dental implantology. A variety of methods have been described in the literature to obtain this objective, including the use of titanium mesh. In this report of two patient cases, CAD-designed and CAM-manufactured custom-made titanium meshes were used in the rebuilding of lost hard tissues. The case results showed the first patient presenting 4.1 mm vertical gain and a width of 8.7 mm and the second patient having 6.7 mm vertical gain and 10.8 mm width. Within the limits of these retrospective case reports, the two cases demonstrate that custom-made CAD/CAM titanium meshes are reliable and safe devices for bone augmentation, especially for vertical and horizontal combined defects. Soft-tissue handling for sufficient mesh coverage is the most critical step when using this technique. Mesh exposure had no influence on bone healing.