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.

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.

Biological mechanisms underlying complications related to implant site preparation.

Implant site preparation is a critical stage of implant surgery that may underpin various complications related to implant surgery. This review discusses the latest available scientific information on risk factors related to implant site preparation. The role of the drilling process in relation to the density of the available alveolar bone, the effects of insertion torque on peri-implant osseous healing, and implant-related variables such as macrodesign and implant-abutment connection are all factors that can influence implant success. Novel information that links osteotomy characteristics (including methods to improve implant initial stability, the impact of drilling speed, and increase of the implant insertion torque modifying the bone-implant interface) with the appropriate instrumentation techniques will be discussed, as well as interactions at the bone-biomaterial interface that may lead to biologic complications mediated by implant dissolution products.

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.

Reducing errors in guided implant surgery to optimize treatment outcomes.

Clinical considerations and treatment criteria in implant placement are constantly evolving. Prosthetically driven implant surgery has become the standard of care to improve short and long-term functional and esthetic outcomes. Therefore, implant position and angulation are planned according to the available bone, anatomical structures, and the requirements of the future prosthetic superstructure. In parallel with these developments, significant progress has been made in data imaging and different software technologies to allow the integration of data within a digital file format. Digitalization in implant surgery enables optimal planning of implant position, as well as the ability to transfer this planning to the surgical field-a process defined as "computer-supported implant planning and guided surgery." The aims of the present review are as follows: (a) to critically appraise the indications and potential "added value" of guided implant surgery, elaborating the main differences between dynamic and static guidance; and (b) to discuss the most important clinical considerations relevant for the different steps of the workflow that might influence the surgical outcome and to offer recommendations on how to avoid or reduce process errors in order to optimize treatment outcomes.

Crestal bone loss and implant failure of prefabricated versus customized abutments: a 10-year retrospective radiological study.

OBJECTIVES: There is no information today about the impact of abutment type on the crestal bone stability. This retrospective study was aimed to evaluate the crestal bone levels (CBL) and failures of implants with prefabricated and customized abutments after the long term. MATERIALS AND METHODS: The mesial and distal CBL around dental implants with prefabricated and custom abutments were recorded. Measures were completed at 5- and 10-year endpoints. RESULTS: Sixty-three patients with 249 implants were included. One hundred twenty-seven implants (51%) were restored with prefabricated and 122 implants (49%) with customized abutments. All the patients received fixed restorations. The results showed that the CBL was higher in patients with custom abutments than the CBL of patients with prefabricated abutments. The mean bone loss around implants with prefabricated abutments was 0.29 mm mesial/0.45 mm distal after 10 years. Meanwhile, the mean bone loss at implants with custom abutments was 1.19 mm mesial/1.27 mm distal (p < 0.05) after 10 years. None of the implants with prefabricated abutments failed up to 10-year follow-up, whereas 4.1% of implants with customized abutments failed. CONCLUSION: Implants with prefabricated abutments present less crestal bone loss compared to customized abutments. CLINICAL RELEVANCE: The selection of abutment type is associated with the crestal bone stability or marginal bone loss.

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.

Anti-inflammatory effect of salt water and chlorhexidine 0.12% mouthrinse after periodontal surgery: a randomized prospective clinical study.

OBJECTIVES: The purpose of this study was to compare the anti-inflammatory efficacy of sodium chloride- and a 0.12% chlorhexidine mouth rinses in patients undergoing minimal invasive periodontal surgery. MATERIALS AND METHODS: Forty-seven patients with a diagnosis of periodontitis and indication for access flap procedure were randomly selected. Group A: a sodium chloride (salt)water-based mouth rinse (test group) or group B: a 0.12% chlorhexidine mouth rinse (control group) administered after surgery. Gingival Index (GI) were evaluated in the whole mouth and in the surgical site at baseline (T1), a week later (T2), and 12 weeks (T3) after the treatment. Total MMP activity was measured in GCF using a commercial kit and plate reader. Medians of total MMP activity and GI were compared for time intervals T1 vs. T2, T1 vs. T3, and T2 vs T3 using Friedman tests and Wilcoxon signed rank tests, and were also compared between test and control using Mann-WhitneyU tests at each timepoint. RESULTS: The average GI values showed significant differences between baseline and T2 (p = 0.0005) and baseline and T3 (p = 0.003) in the test group. CONCLUSION: The sodium chloride-mouth rinse use after periodontal surgery seems to have similar anti-inflammatory properties as CHX mouth rinse and can be used regularly postoperatively after periodontal surgical procedures. CLINICAL RELEVANCE: The use of salt water mouthwash showed an anti-inflammatory effect similar to CHX 0.12% after minimal invasive periodontal surgery. Salt water mouthwash is accessible to the world population and can contribute on the healing process after periodontal surgery.

Titanium Wear of Dental Implants from Placement, under Loading and Maintenance Protocols.

The objective of this review was to analyze the process of wear of implants leading to the shedding of titanium particles into the peri-implant hard and soft tissues. Titanium is considered highly biocompatible with low corrosion and toxicity, but recent studies indicate that this understanding may be misleading as the properties of the material change drastically when titanium nanoparticles (NPs) are shed from implant surfaces. These NPs are immunogenic and are associated with a macrophage-mediated inflammatory response by the host. The literature discussed in this review indicates that titanium NPs may be shed from implant surfaces at the time of implant placement, under loading conditions, and during implant maintenance procedures. We also discuss the significance of the micro-gap at the implant-abutment interface and the effect of size of the titanium particles on their toxicology. These findings are significant as the titanium particles can have adverse effects on local soft and hard tissues surrounding implants, implant health and prognosis, and even the health of systemic tissues and organs.

Connective Tissue Graft vs Platelet-rich Fibrin in the Treatment of Gingival Recessions: A Randomized Split-mouth Case Series.

AIM AND OBJECTIVE: Coronally advanced flap (CAF) with connective tissue graft (CTG) has been considered the gold standard for obtaining complete root coverage. However, some limitations have been reported with the use of CTG, especially because it increases morbidity and leads to postoperative pain and bleeding. Recently, platelet-rich fibrin (PRF) has been used in periodontal plastic surgery for the treatment of gingival recessions (GRs). The aim of this study was to evaluate the outcome of PRF combined with a CAF (test) compared to de-epithelialized connective tissue graft (DeCTG) + CAF (control) for GR coverage. MATERIALS AND METHODS: Ten healthy patients exhibiting mandibular or maxillary Miller class I and II were treated with PRF + CAF or DeCTG + CAF. GR, probing depth (PD), and gingival thickness (GT) were evaluated at baseline, 6 weeks, and 28 weeks postoperatively. RESULTS: GR, PD, and GT differences between the test and control groups at 28 weeks were not statistically significant. GR was 3.30 ± 1.25 mm and 3.00 ± 1.63 mm (control vs test) group (baseline) and -0.10 ± 0.32 vs -0.20 ± 0.42 mm (7 months), respectively. CONCLUSION: Within the limitations of the present study, it can be concluded that localized gingival recessions could be successfully treated with CAF + PRF or CAF + DeCTG. CLINICAL SIGNIFICANCE: This study suggests that PRF membrane may be an alternative and valid graft material for treating localized gingival recessions Miller class I and II.

3D construct of hydroxyapatite/zinc oxide/palladium nanocomposite scaffold for bone tissue engineering.

The purpose of this study was to produce and characterize Hydroxyapatite/Zinc Oxide/Palladium (HA/0.05 wt% ZnO/0.1 wt% Pd) nanocomposite scaffolds and study their mechanical and antibacterial properties, biocompatibility and bioactivity. The initial materials were developed using sol-gel and precipitation methods. Scaffolds were characterized using atomic absorption analysis (AA), scanning electron microcopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM), atomic force microscopy (AFM) and Brunauer-EmmeS-Teller (BET) method. Furthermore, the bioactivity of scaffolds in simulated body fluid (SBF) and the interaction of dental pulp stem cells (DPSCs) with the nanocomposite scaffolds were assessed. Our results showed that the HA/ZnO/Pd (H1), HA/ZnO/Pd coated by 0.125 g chitosan (H2) and HA/ZnO/Pd coated by 0.25 g chitosan (H3) scaffolds possess higher compressive strength and toughness and lower microhardness and density compared to the pure HA (H0) scaffolds. Immersion of samples in SBF showed the deposition of apatite on the surface of the scaffolds. The biocompatibility assay indicated lower cell proliferation on the H1, H2 and H3 in comparison to the H0. The antibacterial results obtained show a significant impact by loading Pd/ZnO on HA in the deactivation of microorganisms in vitro.

Assessment of routine diet (garlic consumption) as a pre- and postoperative protocol in oral and maxillofacial surgical interventions: An evidence-based literature review.

BACKGROUND: It was hypothesized that pathological bleeding (PB) during and/or after oral surgical procedures is higher in systemically healthy patients who have a history of garlic intake compared to controls (patients without a history of garlic consumption). AIM: The aim of the present review article was to identify studies in which garlic consumption was included as a patient management protocol before and after oral and maxillofacial surgery (OMFS). METHODS: A review of pertinent indexed literature was performed. The focused question that was addressed was "Has diet (garlic consumption) been considered as a patient management protocol before and after OMFS?" The inclusion criteria were: (a) studies published in indexed databases, (b) original studies, (c) studies on OMFS, and (d) studies that considered diet (garlic consumption) as a patient management protocol before and after OMFS. Literature review, commentaries, letters to the editor, and studies published in non-indexed resources were excluded. The pattern of the present review was customized to summarize the pertinent information. RESULTS: The initial search using the terms "oral," maxillofacial," "protocol," and "surgery" yielded 1478 studies. The addition of the term "diet" to this search strategy reduced the number of studies to five. Further filtration of these studies using the terms "garlic" and/or "Allium sativum" showed no studies. CONCLUSIONS: Garlic intake predisposes patients to PB. However, there are no studies in the indexed literature that have considered the inclusion of garlic consumption in patient management protocols before and after OMFS.

"Religious Belief": An Undervalued Ethical Inclusion Criterion for Clinical Trials on Bone Grafting Procedures.

The aim of the present review was to assess randomized controlled trials (RCTs) on bone grafting procedures that included religious belief as an eligibility criterion. Indexed databases were searched up to and including February 2019 using different search strategies. In strategy 1, the following terms were used: (a) belief; (b) bone graft; (c) faith; (d) inclusion; (e) exclusion; (f) eligibility; (g) criteria; (h) randomized clinical trial; (i) religion; and (j) xenograft. In strategy 2, the following terms were used in addition to those used in strategy 1: Xenografts AND oral surgery OR xenografts AND maxillofacial OR xenografts AND dental implants. These searches were filtered using the terms "Randomized clinical trial" and "human studies". The initial search yielded 3932 studies. Filtration of results using the terms "Randomized clinical trial" and "human studies" showed 0 studies. Evaluation of patients' religious beliefs seems to be undervalued in RCTs related to the placement of xenografts. This is an essential and ethical criterion that should be taken into consideration prior to inclusion of participants and signing the informed consent form for RCTs related to the placement of bone grafts.

Chronic hyperglycemia as a risk factor in implant therapy.

It has been estimated that by 2030, the number of patients with diabetes aged > 64 years will be > 82 million in underdeveloped countries, and > 48 million in developed countries. Chronic hyperglycemia delays wound healing by reducing the expression of growth factors in the wound fluid and re-epithelialization. Impaired wound healing in patients with diabetes has also been associated with inhibition of the production of stromal cell-derived factor-1alpha by several tissues including bone marrow, brain, heart, spleen, and gingivae. Chronic hyperglycemia interferes with the osseointegration of implants by deferring the expression of fibronectin and integrins. Results from experimental studies have shown a significantly higher bone-to-implant contact around implants placed in healthy animals compared with animals with streptozotocin-induced diabetes. Moreover, persistent hyperglycemia plays a role in abnormal differentiation of osteoclasts, thereby making bone tissue more susceptible to resorption. Furthermore, persistent hyperglycemia has also been associated with increased peri-implant soft tissue inflammation (increased peri-implant bleeding on probing and probing depth) and crestal bone loss. Clinical studies have shown that under optimal glycemic control dental implants can show success and survival rates of up to 100% in patients diagnosed with diabetes. Although patients with diabetes can undergo dental implant therapy and can exhibit implant survival similar to those in systemically healthy individuals, the contribution of glycemic control and regular oral hygiene maintenance cannot be disregarded.

Tobacco-product usage as a risk factor for dental implants.

The oral cavities of tobacco smokers and users of smokeless tobacco products are exposed to high concentrations of nicotine. A limited number of animal studies have assessed the effect of nicotine on osseointegration. Results from experimental studies have reported a statistically significant decrease, at 4 weeks of follow-up, in bone-to-implant contact among rats exposed to nicotine compared with unexposed rats. Nicotine increases the production of inflammatory cytokines (such as interleukin-6 and tumor necrosis factor-alpha) by osteoblasts. Waterpipe, pipe, and cigarette smokers are at increased risk of developing oral cancer, periodontal disease, and alveolar bone loss. One explanation for this is that smokers (regardless of the type of tobacco product) are exposed to similar chemicals, such as nicotine, tar, oxidants, polyaromatic hydrocarbons, and carbon monoxide. Moreover, raised levels of proinflammatory cytokines have been identified in the gingival crevicular fluid of cigarette smokers with peri-implant diseases. Therefore, it is hypothesized that nicotine and chemicals in tobacco smoke induce a state of oxidative stress in peri-implant tissues (gingiva and alveolar bone), thereby increasing the likelihood of peri-implant disease development via an inflammatory response, which if left uncontrolled, will result in implant failure/loss. In this regard, tobacco smoking (including cigarettes, waterpipe, and pipe) is a significant risk factor for peri-implant diseases. The impact of vaping electronic cigarettes using nicotine-containing e-juices remains unknown. Habitual use of smokeless tobacco products is associated with oral inflammatory conditions, such as oral precancer, cancer, and periodontal disease. However, the effect of habitual use of smokeless tobacco products on the success and survival of dental implants remains undocumented.

Molecular tools for preventing and improving diagnosis of peri-implant diseases.

Peri-implantitis is an inflammatory disease of tissues surrounding osseointegrated dental implants. Inflammation affecting soft and hard peri-implant tissues can cause alveolar bone resorption and subsequent implant loss. Clinical surveillance and early diagnosis are of paramount importance to reduce clinical failures and improve implant survival. Current diagnosis of implants is based on clinical and radiological signs. Molecular tests are an emerging diagnostic methodology, which potentially can help to detect and prevent early peri-implantitis and monitor the efficacy of therapy as well. A plethora of potential biomarkers are potentially available to support the clinical diagnosis of peri-implantitis. However, conflicting diagnostic conclusions have been reached, probably related to weak statistical results due to limited sample size or disease heterogeneity. The present paper reviews candidate diagnostic biomarkers for peri-implantitis, including infective agents, genetic susceptibility factors, and key proteins related to inflammation and tissue remodeling.

Soft tissue-related complications and management around dental implants.

Implant installation for replacing missing teeth is a frequent treatment procedure with high long-term survival and success rates. However, the success of implant therapy may be jeopardized by several complications related to mistakes in treatment planning, surgical procedure, management of hard and soft tissues, and infections. Increasing evidence suggests that the stability of the soft tissues surrounding osseointegrated dental implants may substantially influence long-term clinical stability and esthetics. Therefore, when implant therapy is planned, the clinician must not only be able to perform the appropriate steps to maintain/create a stable soft tissue, but also needs to be aware of the potential sources for complications and possess the adequate knowledge for their appropriate management. The present paper provides an overview of the most important aspects related to the prevention and management of soft tissue-related complications in conjunction with implant therapy. The current literature indicates that the presence of an adequate width of keratinized attached mucosa around dental implants may lead to better soft and hard tissue stability, less plaque accumulation, limited soft tissue recession, and lower incidence of peri-implant mucositis. Proper implant positioning by carefully considering appropriate mesio-distal and bucco-lingual dimensions and implant angulation may prevent the loss of interdental soft tissues and development of soft tissue recessions. To optimize the width of keratinized attached mucosa, the appropriate soft tissue augmentation protocol should be selected for each particular indication. When the use of autogenous soft tissue grafts is planned, a thorough knowledge of the anatomical structures is mandatory in order to harvest soft tissue grafts of an appropriate quality and quantity and to avoid/minimize postoperative complications. Finally, the clinician needs to master the necessary steps in order to manage complications related to extensive bleeding and tissue necrosis that may occur in conjunction with soft tissue augmentation procedures.

Concepts for prevention of complications in implant therapy.

The use of dental implants is nowadays a well-accepted and highly predictable treatment modality for restoring the dentition and reestablishing the masticatory function of edentulous and partially edentulous patients. Despite the high predictability and excellent long-term survival rates reported for implant therapy, complications may still occur and can jeopardize both short- and long-term success. The present paper provides an overview on the most important aspects related to the etiology, prevention, and management of complications associated with implant therapy. Data from the literature indicate that a number of factors, such as surgical trauma, implant diameter, type of implant-abutment connection, abutment disconnection and reconnection, presence of microgap, and implant malpositioning, can substantially influence the biologic processes of bone remodeling and biofilm formation, thus increasing the rate of short- and long-term hard- and soft-tissue complications. Other factors, such as excess cement at cement-retained prosthetic restorations, abutment mobility, and infections (e.g. peri-implant mucositis and peri-implantitis) caused by bacterial biofilm, are further causes for complications and failures. More recent evidence also indicates that besides the need for sufficient bone volume surrounding the implant, the presence of an adequate width and thickness of attached mucosa may improve biofilm control and limit crestal bone resorption. Furthermore, emerging evidence points also to the pivotal role of human factors as one of the most important causes of complications in implant dentistry. It can be concluded that clinicians need to consider all biologic and biomechanical factors affecting implant placement and survival, as well as undergo adequate training to improve their surgical skills to control and prevent implant complications. Careful patient selection and control of environmental and systemic factors, such as smoking, diabetes etc., coupled with an accurate surgical and prosthetic planning, enable a better prevention and control of infections.

Effects of occlusal forces on the peri-implant-bone interface stability.

The occlusal forces and their influence on the initiation of peri-implant bone loss or their relationship with peri-implantitis have created discussion during the past 30 years given the discrepancies observed in clinical, animal, and finite element analysis studies. Beyond these contradictions, in the case of an osseointegrated implant, the occlusal forces can influence the implant-bone interface and the cells responsible for the bone remodeling in different ways that may result in the maintenance or loss of the osseointegration. This comprehensive review focuses on the information available about the forces transmitted through the implant-crown system to the implant-bone interface and the mechano-transduction phenomena responsible for the bone cells' behavior and their interactions. Knowledge of the basic molecular biology of the peri-implant bone would help clinicians to understand the complex phenomenon of occlusal forces and their effects on the implant-bone interface, and would allow better control of the negative effects of mechanical stresses, leading to therapy with fewer risks and complications.