Retrospective clinical study of 842 clasp-retained removable partial dentures with a metal framework: survival, maintenance needs, and biologic findings.

OBJECTIVES: To evaluate clasp-retained removable partial dentures (C-RPDs) with a metal framework for survival, maintenance requirements, and biological implications. METHOD AND MATERIALS: C-RPDs were retrospectively analyzed based on patient records. Treatment failure was defined as fracture of a framework component (metal base or connector) or loss of an abutment tooth. Other outcome variables included factors that might conceivably impact C-RPD survival (maxilla vs. mandible, Kennedy classes, opposing dentitions, treatment by students vs. certified dentists), mobility and caries of abutment teeth (in relation to clasp designs), and maintenance requirements (relining, clasp or resin fractures). Differences were evaluated by appropriate statistical tests at the P ≤ .05 level. RESULTS: A total of 612 patients (339 men, 273 women) 60.0 ± 11.5 years old at delivery were included, covering 842 C-RPDs and a mean observation period of 42.1 ± 33.2 months. Kaplan-Meier C-RPD survival was 76.2% after 5 years and 49.5% after 10 years. Biological complications (i.e. loss of abutment teeth) accounted for the vast majority (95.6%) of C-RPDs failures, and Kaplan-Meier C-RPD survival was significantly better in the mandible (P = .015). Some clasp designs contributed significantly to caries and removal of abutment teeth (both P < .05). No other significant differences were noted. CONCLUSION: Tooth loss both emerges as the main cause of C-RPDs failure and might be amenable to careful selection of clasp designs. Overall, better C-RPD survival should be expected in the mandible. A non-contributory role of Kennedy classes and opposing dentitions is tentatively suggested based on numerically heterogeneous subgroups.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Biological Characterization, Properties, and Clinical Use of a Novel Homeopathic Antiseptic Oral Recovery Kit: A Narrative Review.

Most available antiseptic solutions have strong antibacterial effects, but many also possess major cytotoxic effects on gingival fibroblasts, osteoblasts, osteoprogenitor cells, and/or epithelial cells. A novel VEGA Oral Care Recovery Kit (StellaLife) consisting of 16 active ingredients that are monographed in the Homeopathic Pharmacopeia of the United States (HPUS) has gained tremendous momentum as a replacement for more cytotoxic oral rinses such as chlorhexidine. While accumulating evidence has thus far supported its use, little of the gathered data have fully described the properties of the oral formulation. Therefore, the aim of the present review article was 3-fold. First, a biological characterization regarding the active ingredients found in StellaLife Recovery Kit including their biological properties was assessed in 4 predominant categories; 1) antimicrobial resistance, 2) accelerated wound healing, 3) pain management control, and 4) anti-cancer properties. The second aim of this review article was to assess both fundamental and clinical research to date comparing VEGA oral rinse (StellaLife) to the more commonly utilized CHX for differences regarding their effect on decreasing bacterial loads as well as cell viability, survival, proliferation, and expression of both regenerative cytokines and inflammatory markers. Lastly, clinical case examples are presented describing the use of StellaLife remedies in a variety of clinical situations. These include but are not limited to wisdom-tooth extraction, extraction site management, dental implants and ridge augmentation, soft-tissue grafting procedures, frenectomies, and also temporary relief of dry sockets, dry mouth, aphthous ulcers, mucositis, lichen planus, among others. In summary, findings from the present review article provide evidence from basic laboratory experiments that validate clinical studies supporting the use of the StellaLife oral rinse regarding its superior biocompatibility and wound healing properties when compared to common antiseptic solutions such as CHX.

Which Histometric Analysis Approach Is More Reliable for Assessing Histological Bone Tissue Samples?

This study aims to evaluate the grid of Merz and ImageJ methods for histometric quantification, verifying which is more reliable and defining which is most suitable based on the time required to perform. Thirty histological samples of maxillary sinuses grafted with xenografts were evaluated using an optical light microscope attached to an image capture camera and connected to a microcomputer. The images were digitalized and recorded as a TIFF image, and the new bone formation was evaluated using the grid of Merz and ImageJ. The Bland-Altman analysis was used to identify the agreement between the methods and determine suitable future research options. The timing of the quantification was also performed to identify a possible advantage. The mean value for the quantification analysis timing for the grid of Merz was 194.9 ± 72.0 s and for ImageJ was 871.7 ± 264.4, with statistical significance between the groups (p = 0.0001). The Bland-Altman analysis demonstrated a concordance between the methods, due to the bias being next to the maximum concordance (-1.25) in addition to the graphic showing the scattering points next to the mean of differences and inside of limits of agreement. Thus, it was demonstrated that the grid of Merz presents reliable outcomes and advantages over the ImageJ methodology regarding the time spent to contour the areas of interest.

Drug-associated bone resorption with potential dental and implant implications.

Every year more and more innovative pharmacological agents are introduced medicine, to treat systemic diseases. Due to these rapid and recent advancements, many patients are receiving treatment with a high variety of drugs, such as selective serotonin reuptake inhibitors, bisphosphonates, tumor necrosis factor (TNF)-α inhibitors, cyclosporine, and steroids. Since implant and osseous surgery are common treatment modalities used, within dentistry, it is of critical important to acknowledge and discuss the potential effects of selective serotonin reuptake inhibitors, bisphosphonates, TNF-α inhibitors, cyclosporine, and steroids, on bone healing. The present paper discusses the possible detrimental ramifications and risks these drug classes may have on bone healing.

Thermal Effects of Diode Laser-Irradiation on Titanium Implants in Different Room Temperatures In Vitro.

Objective: The aim of this study was to determine the thermal effects of diode laser irradiation on titanium implants. Methods: An implant (3.5 × 11 mm) was placed into a bovine bone block. A three-wall intrabony defect was created to simulate peri-implant defect. Two thermocouples were secured to the apical and coronal surfaces to measure temperature changes (ΔT) during irradiation. The block was placed in a 37°C water bath and at room temperature (21°C). The defect was irradiated with different diode lasers (fiber 300 µm), while the coronal part of the implant was slightly emerging from the water. While the laser tip was positioned parallel to the implant, the defect was irradiated for 30 sec at 2 W in continuous and pulsed mode. Twenty laser irradiations were performed for each laser wavelength for assessment of ΔT. The linear mixed model was used for comparative statistics. Results: The 980 nm pulsed laser resulted in the highest ΔT (°C) at the coronal (22.45 ± 2.1/14.15 ± 0.13) and apical level (5.4 ± 0.56/3.56 ± 0.35) when this laser was used in both room temperature and water bath conditions, respectively. Similarly, highest ΔT (p < 0.0001) for the 810 nm was 14.3 ± 1.6/12.51 ± 0.63 and apical 3.42 ± 0.52/2.58 ± 0.25, for the 970 nm was 13 ± 1.4/9.93 ± 0.47 and apical 2.89 ± 0.19/2.01 ± 0.19 compared to the 940 nm laser coronally 10.1 ± 0.6/9.19 ± 0.35 and apically 1.67 ± 0.34/1.80 ± 0.17. The coronal part of the implant surpassed the critical threshold of 10°C when irradiated with each of the lasers in the room temperature conditions. Conclusions: Within the limitations of the study, the 940 nm laser seems to control better the risks of overheating during implant irradiation.

Comparing the Use of Diode Lasers to Light-Emitting Diode Phototherapy in Oral Soft and Hard Tissue Procedures: A Literature Review.

Objective: In dentistry, patient and physician adoption of diode lasers and light-emitting diodes (LEDs) continues to increase as research indicates that diode lasers and LEDs may be used for surgical and nonsurgical procedures. The goal of this literature review was to critically analyze randomized controlled trials and experimental trials to provide evidence-based recommendations on the therapeutic uses of diode lasers and LEDs in oral applications based on published efficacy and safety data. Methods: A literature review was performed of published literature on patients receiving periodontal and oral surgery treatment that included the use of diode lasers and/or the use of LED phototherapy to determine if the outcomes of phototherapy were superior to conventional therapy and if one form of phototherapy was superior to the other. Results: Eighteen original clinical trials and experimental studies were suitable for review. The diode laser was presented as an effective tool in soft tissue management due to its cutting precision, incision depth, analgesic effects, and elimination of bacterial load and in periodontal applications for probing depth reduction when used as an adjunct to scaling and root planing (SRP). LEDs also served as an effective tool for pain management, wound healing, and efficacy when used as an adjunct to SRP. Other than one study, all the available studies reviewed were either evaluating the efficacy of diode lasers or LEDs, but not both. Therefore, the results for determining the more effective tool were inconclusive. Conclusions: According to existent data, diode lasers and LEDs are equally effective tools for the phototherapy in periodontology and oral surgery. Although fewer studies exist examining the use of LED for phototherapy, the studies all revealed positive results. Further clinical comparative investigations utilizing both diode lasers and LED are needed to determine superiority of this application for periodontal management and oral surgery.