Analysis of the Marginal Continuity in Different Designs of Monolithic Zirconia Inlay-Retained Fixed Dental Prostheses: An In Vitro Study.

PURPOSE: To evaluate the marginal integrity of three inlay-retained fixed dental prosthesis (IRFDP) designs fabricated using monolithic zirconia. MATERIALS AND METHODS: In total, 30 IRFDPs were fabricated using 4-YTZP monolithic zirconia and randomly divided into three groups according to the cavity design. Groups ID2 and ID1.5 received an inlay cavity preparation, which includes a proximal box and an occlusal extension with a depth of 2 mm or 1.5 mm, respectively. Group PB received a proximal box cavity preparation without an occlusal extension. The restorations were fabricated and cemented using a dual-cure resin cement (Panavia V5) and subjected to an equivalent of 5 years of aging. The specimens were evaluated under an SEM to measure marginal continuity before and after the aging process. RESULTS: During the whole 5-year aging process, no specimens showed signs of cracking, fracture, or loss of retention in any restorations. In the SEM analysis, most marginal defects observed in the restorations were areas of microgaps at the tooth/cement interface (TC) or zirconia/cement interface (ZC), resulting in loss of adaptation. There was a significant difference between the groups after the aging process at both the TC (F = 4.762, P < .05) and ZC (F = 6.975, P < .05), with Group ID2 presenting the best performance. There was a significant difference between TC and ZC in all groups (P < .05), with ZC presenting more gaps in all groups. CONCLUSIONS: Inlay cavity designs including a proximal box and an occlusal extension exhibited better marginal stability than a proximal box without occlusal extension.

A 24-month randomized clinical study of flowable bulk-fill resin composites in Class III restorations.

Background: The 24-month clinical performance of 3 commercially available flowable bulk-fill resin composites in Class III restorations was evaluated. Material and Methods: Forty-two patients, 27 females (64.3%) and 15 (35.7%) males, received at least 3 Class III restorations that never exceeded 4 mm depth and width. One hundred thirty-eight teeth, divided up into three groups (n=46), were randomly restored with Admira Fusion x-base (AFB), Estelite Bulk Fill Flow (EBF) and SDR flow+ (SDR) in one single increment. A 2-step self-etch adhesive system Clearfil SE Bond (C-SE) with selective enamel etching was used for all restorations. The restorations were clinically evaluated using a slightly modified USPHS criteria at the baseline and every 6 months for 24 months. Success rates of each material between the baseline and at 24 months were compared with the McNemar test. At each timepoint, the comparison of the clinical performance among materials in terms of the ratings of the considered criteria was analyzed by using the Friedman and Cochran's Q tests. Results: At the end of the 24-month follow-up, the overall clinical success rate was 100% for each tested material. However, significant differences among the composites were highlighted for several criteria involving the marginal adaptation, marginal discoloration, surface texture, surface staining and color match. Conclusions: The flowable bulk-fill resin composites tested showed an overall good effectiveness for Class III restorations after the 24 months, although significant rating differences among the materials emerged for some specific clinical criteria. Key words:Bulk-fill, Class III restoration, flowable composite, clinical study, self-etching adhesive.

Fracture load comparison of a new Fiber-Reinforced Composite and Zirconia in All-on-Four Prosthesis: An In Vitro Study.

PURPOSE: To compare the fracture load of two framework materials, zirconia and a new fiber-reinforced composite (FRC), for full-arch implant-supported rehabilitations using various cross- sections. MATERIAL AND METHODS: A cobalt-chromium metal model simulating the all-on-four concept and including 2 anterior straight and 2 posterior 45- degree angled multi-unit digital implant analogs was manufactured. 4 straight multi-unit abutments were screwed onto the implant analogs. The metallic model was scanned, and 18 frameworks were fabricated, consisting of 9 made of zirconia and 9 made of fiber-reinforced composite (FRC). The frameworks were then divided into 6 groups, with each group consisting of 3 frameworks (n=3). Group division was based on material type (Zirconia or FRC Trilor) and framework cross-section: 3.5 x 6 mm2, 5.5 x 6 mm2, or 7.5 x 6 mm2. All specimens underwent thermocycling in 2 baths (5 ͦ c- 55 ͦ c for 2350 cycles). Subsequently, the frameworks were cemented to the abutments of the metal model and subjected to a load-to-failure bending test at 3 different points using a universal testing machine (crosshead speed: 1 mm/min) until complete fracture occurred (according to ISO/TS 11405:2015). Descriptive statistics were used to present quantitative variables as means ± standard deviations. To compare two means, Student's t-test or Mann-Whitney test was utilized, and for three means, ANOVA test was used. RESULTS: The FRC group with a 7.5 x 6 mm2 cross-section exhibited the highest load-to-failure values (ranging from 1020 N to 2994N) , while the zirconia group with a 3.5 x 6 mm2 cross-section recorded the lowest values (ranging from 212 N to 1287 N). The material type and framework cross-section significantly affected the mean load-to-fracture values (p< 0.05). Regardless of the framework cross-section, the FRC group exhibited higher fracture loads than the zirconia group. In both materials, fracture load values were increased with larger framework cross-sectional areas, with the highest values observed at the inter-implant midpoint. CONCLUSION: The FRC Trilor demonstrated a fracture load that make it a suitable alternative to zirconia for all-on-four implant prosthetic frameworks.

Simultaneous Dual-Wavelength Laser Irradiation against Implant-Adherent Biofilms of Staphylococcus aureus, Escherichia coli, and Candida albicans for Improved Antimicrobial Photodynamic Therapy.

The efficiency of antimicrobial photodynamic therapy (PDT) might be improved by using multiple wavelengths. This study investigates the sensitivity of implant-adherent biofilms of Staphylococcus aureus, Escherichia coli, and Candida albicans to indocyanine green (ICG)-808 nm diode laser, toluidine blue O (TBO)-635 nm diode laser, and hydrogen peroxide (HP)-980 nm diode laser and their combination when irradiated with dual-wavelength laser irradiation (simultaneously 980-635 nm or 980-808 nm). After an incubation period of 72 h, the infected implants were randomly divided into seven different treatment modalities: Control, HP, HP-PDT, TBO-PDT, HP-TBO-PDT, ICG-PDT, and HP-ICG-PDT. After the treatments, the colony-forming units (CFUs)/mL and reactive oxygen species (ROS) generation were determined. All evaluated disinfection methods were significantly effective against the three investigated bacteria compared to the control. The combined treatment of HP-ICG-PDT or HP-TBO-PDT had the greatest antibacterial effect compared to each treatment alone. There were statistical differences between HP-ICG-PDT and ICG-PDT or HP-TBO-PDT and TBO-PDT for all three bacteria studied. PDT with simultaneous dual-wavelength laser irradiation is an efficient strategy to improve the therapeutic effect of PDT.

The Effect of Different Output Powers of Blue Diode Laser along with Curcumin and Riboflavin against Streptococcus mutans around Orthodontic Brackets: An In Vitro Study.

OBJECTIVES: The aim of the present study was to determine the effects of antimicrobial photodynamic therapy (aPDT) using the blue diode laser (BDL) with different output powers and the photosensitizers riboflavin and curcumin on reducing the number of Streptococcus mutans around orthodontic brackets. MATERIALS AND METHODS: A total of 36 orthodontic brackets were contaminated with S. mutans and randomly assigned to 12 groups as follows: control, riboflavin alone, riboflavin + BDL with an output power of 200, 300, 400, or 500 mW, and curcumin alone, curcumin + BDL with an output power of 200, 300, 400, or 500 mW, and 0.2% chlorhexidine (CHX-positive control). Orthodontic brackets were irradiated with a BDL (wavelength 445 nm) at a power density of 0.4-1.0 W/cm2 for 30 s. All orthodontic brackets were examined under a stereomicroscope at 10× magnification. Mean colony-forming units (CFUs)/mL were measured before and after treatment. A one-way analysis of variance with Tukey's post hoc test was performed to compare CFU/mL between groups. RESULTS: CHX and curcumin plus BDL with an output power of 500 mW had the highest reduction in S. mutans colony numbers (p < 0.001). The curcumin groups were more effective than the riboflavin groups. Riboflavin alone and riboflavin + BDL with an output power of 200 mW showed no significant difference from the control group (p = 0.99 and 0.74, respectively). CONCLUSION: Our results suggest that aPDT using curcumin as a photosensitizer plus BDL with an output power of 500 mW and a power density of 1.0 W/cm2 at a wavelength of 445 nm can effectively reduce colonies of S. mutans around stainless steel brackets.

Photons Induce Vesicular Exocytotic Release of Glutamate in a Power-Dependent Way.

Increasing evidence indicates that photobiomodulation, based on tissue irradiation with photons in the red to near-infrared spectrum, may be an effective therapeutic approach to central nervous system disorders. Although nervous system functionality has been shown to be affected by photons in animal models, as well as in preliminary evidence in healthy subjects or in patients with neuropsychiatric disorders, the mechanisms involved in the photobiomodulation effects have not yet been clarified. We previously observed that photobiomodulation could stimulate glutamate release. Here, we investigate mechanisms potentially involved in the glutamate-releasing effect of photons from adult mouse cerebrocortical nerve terminals. We report evidence of photon ability to induce an exocytotic vesicular release of glutamate from the terminals of glutamatergic neurons in a power-dependent way. It can be hypothesized that photobiomodulation, depending on the potency, can release glutamate in a potentially neurotoxic or physiological range.

The Evaluation of SWEEPS Plus Antimicrobial Photodynamic Therapy with Indocyanine Green in Eliminating Enterococcus faecalis Biofilm from Infected Root Canals: An In Vitro Study.

OBJECTIVES: This study aimed to assess the efficacy of shockwave-enhanced emission photoacoustic streaming (SWEEPS) plus antimicrobial photodynamic therapy (aPDT) using indocyanine green (ICG) for the elimination of Enterococcus faecalis biofilm from infected root canals. MATERIALS AND METHODS: thirty sound human single-canal teeth were chosen and standardized to have 12 mm of root length. The root canals were shaped and prepared by means of ProTaper rotary files. After sterilization of the teeth, the canals were inoculated with E. faecalis for 2 weeks. The teeth were then randomly divided into six groups (n = five) of control, ICG, ICG + 808 nm diode laser, ICG + SWEEPS, ICG + 808 nm diode laser + SWEEPS, and 5.25% sodium hypochlorite (NaOCl). Following treatment, the number of colony-forming units (CFUs)/mL were calculated for each group. Statistical analysis was carried out using one-way ANOVA. For multiple comparisons, Tukey's test was used as the post hoc test. RESULTS: NaOCl alone showed the highest efficacy (p < 0.001). The ICG + 808 nm diode laser + SWEEPS group displayed significantly lower amounts of bacteria than either the ICG + 808 nm diode laser or SWEEPS (p < 0.001). There was a statistically significant difference detected between the ICG + 808 nm diode laser and ICG + SWEEPS (p = 0.035). CONCLUSIONS: SWEEPS can effectively increase the photosensitizer distribution in the root canal space, and its application along with irrigants can bring about promising results.

Analysis of the Marginal Continuity in Different Designs of Monolithic Zirconia Inlay-Retained Fixed Dental Prosthesis: (An in vitro Study).

PURPOSE: To evaluate the marginal integrity of three inlay-retained fixed dental prosthesis (IRFDP) designs fabricated using monolithic zirconia. MATERIALS AND METHODS: Thirty inlay-retained fixed dental prostheses were fabricated using a 4-YTZP monolithic zirconia, and divided randomly into 3 groups according to the cavity design. Group ID2 and ID1.5 received an inlay cavity preparation which includes a proximal box and an occlusal extension with a depth of 2 mm or 1.5 mm respectively. Group PB received a proximal box cavity preparation without an occlusal extension. The restorations were fabricated and cemented using a dual cure resin cement (Panava V5) and subjected to an equivalent of 5 years of ageing. The specimens were evaluated under a SEM to measure marginal continuity before and after the ageing process. RESULTS: During the whole 5-year ageing process, no specimens showed signs of cracking,fracture or loss of retention in any of the restorations. In the SEM analysis, most of the marginal defects observed in the restorations were areas of micro-gaps at the TC (tooth/cement interface) or ZC (zirconia/cement interface) resulting in loss of adaptation. There was a significant difference between the groups after the ageing process at both the TC (F=4.762, p<.05) and ZC (F=6.975, p<.05), with group ID2 presenting the best performance. There was a significant difference between TC and ZC in all groups (p<.05) with ZC presenting more gaps in all groups. CONCLUSION: Inlay cavity design including a proximal box and an occlusal extension exhibited better marginal stability than a proximal box without occlusal extension.

Comparison between the Flapless Surgical Approach and a Novel Single Incision Access in Terms of Recovery Time and Comfort after Extraction of Impacted Inferior Third Molars: A Randomised, Blinded, Split-Mouth Controlled Clinical Trial.

The recent attention to quality of life and oral health care procedures reflects a renewed 'patient-based' approach to dealing with non-life-threatening conditions. In the current study, we proposed a novel surgical approach to the extraction of impacted inferior third molars (iMs3) through a randomised, blinded, split-mouth controlled clinical trial following the CONSORT guidelines. The novel surgical procedure, hereinafter referred to as single incision access (SIA), will be compared with our previously described flapless surgical approach (FSA). The predictor variable was the novel SIA approach, involving access through a single incision without removal of soft tissue, on the impacted iMs3. The primary endpoint was the acceleration of the iMs3 extraction healing time. The secondary endpoints were the incidences of pain and oedema as well as gum health (pocket probing depth and attached gingiva). The study was carried out on 84 teeth of 42 patients with both iMs3 impacted. The cohort was composed of 42% Caucasian males and 58% Caucasian females, aged 23.8 ± 7.9 (17-49) years. We observed faster recovery/wound-healing on the SIA side (33.6 ± 4.3 days) than at the FSA side (42.1 ± 5.4 days; p < 0.05). The FSA approach confirmed the evidence previously detected concerning early post-surgery improvement in terms of attached gingiva and reduced oedema and pain, with respect to the traditional envelope flap. The novel SIA approach follows the early positive post-surgery FSA results.

Evaluation of Enamel Surfaces after Different Techniques of Interproximal Enamel Reduction.

According to the literature, interproximal enamel reduction (IER) has become a consolidated technique used in orthodontic treatments to gain space in particular situations such as dental crowding, non-extractive therapies, tooth-size discrepancies, and prevention of dental relapse. There are different methods to realize stripping, and enamel surfaces resulting after this procedure can be analyzed with SEM. The aim of this study was to analyze how different devices of IER leave the surface of the teeth. One hundred and sixty freshly extracted, intact human lower incisors were included in the study, fixed in a plaster support, and then processed with four different techniques of enamel reduction and finishing. Then, they were divided randomly into eight groups (A1-A2, B1-B2, C1-C2, D, and E), each containing twenty teeth. The A, B, and C groups were divided into two subgroups and then all the teeth were observed at SEM. Each digital image acquired by SEM showed that there were streaks on the surfaces, due to the cutter used. The results of this study showed that only group C2 (tungsten carbide bur followed by twelve steps of medium-fine-ultrafine 3M Soft Lex disks) has a few line, which is very similar to group E (untreated group), while the other groups have a lot of lines and show a rougher final surface.

"Sticky Bone" Preparation Device: A Pilot Study on the Release of Cytokines and Growth Factors.

Sticky bone, a growth factor-enriched bone graft matrix, is a promising autologous material for bone tissue regeneration. However, its production is strongly dependent on manual handling steps. In this sense, a new device was developed to simplify the confection of the sticky bone, named Sticky Bone Preparation Device (SBPD®). The purpose of this pilot study was to investigate the suitability of the SBPD® to prepare biomaterials for bone regeneration with autologous platelet concentrates. The SBPD® allows the blending of particulate samples from synthetic, xenograft, or autogenous bone with autologous platelet concentrates, making it easy to use and avoiding the need of further manipulations for the combination of the materials. The protocol for the preparation of sticky bone samples using the SBPD® is described, and the resulting product is compared with hand-mixed SB preparations regarding in vitro parameters such as cell content and the ability to release growth factors and cytokines relevant to tissue regeneration. The entrapped cell content was estimated, and the ability to release biological mediators was assessed after 7 days of incubation in culture medium. Both preparations increased the leukocyte and platelet concentrations compared to whole-blood samples (p < 0.05), without significant differences between SB and SBPD®. SBPD® samples released several growth factors, including VEGF, FGFb, and PDGF, at concentrations physiologically equivalent to those released by SB preparations. Therefore, the use of SBPD® results in a similar product to the standard protocol, but with more straightforward and shorter preparation times and less manipulation. These preliminary results suggest this device as a suitable alternative for combining bone substitute materials with platelet concentrates for bone tissue regeneration.

Comparison and Effect of Common Beverages on Color Stability of Different Esthetic Restorative Materials: An In Vitro Study.

AIM: The aim of this in vitro study is to assess the color stability of different esthetic veneer restorative materials (feldspathic ceramic, hybrid ceramic, zirconia-reinforced lithium silicate glass ceramic, and composite resin) after being exposed to commonly consumed beverages that have staining potential. MATERIALS AND METHODS: Sixty specimens were prepared into rectangular blocks with fixed dimensions of 10 × 12 × 2.5 mm. Machinable feldspathic ceramic (FC), zirconia-reinforced lithium silicate glass ceramic (LS), and a hybrid ceramic (HC) were milled using CAD/CAM (n = 15), and specimens of microparticle composite resin (MPC) were manually prepared by with the same dimensions (n = 15). All specimens were randomly divided into three subgroups (= 5) according to immersing solutions used (coffee, black tea, and red wine). All specimens were immersed for a period of 72 hours. A colorimetric evaluation was done for each specimen before and after immersion using a spectrophotometer and the difference in color was calculated according to the CIE-Lab system. To analyze the data, two-way ANOVA and one-way ANOVA tests of significance were used to compare between the different study groups, followed by pairwise comparisons using post hoc test (Tukey). RESULTS: Different restorative materials showed statistical significance regarding color change after staining (p < 0.001); however, no statistical significance in color change (p > 0.05) was found between the different beverages used. CONCLUSION: All tested ceramic materials had better color stability compared with composite resin. All the staining beverages used in the current study might cause a significant color change in the tested restorative materials. CLINICAL SIGNIFICANCE: The color stability of esthetic restorative materials affects their clinical performance in the oral cavity, where the restorative materials are usually exposed to staining beverages that are frequently consumed by patients. Therefore, it is important to understand the staining effect of the different beverages on esthetic restorative materials.

Immediate Implants in the Aesthetic Zone: Is Socket Shield Technique a Predictable Treatment Option? A Narrative Review.

(1) Background. Dental implant placement in the anterior region requires extreme precision due to relatively high aesthetic demand. This narrative review aimed to analyse some of the available clinical studies of the socket-shield technique and determine its viability for dental implant survival/success and complication rates. (2) Methods. An electronic search for publications was performed using the Cochrane, PubMed-MEDLINE, Web of Science, and Google Scholar databases. All electronic searches included human clinical and animal studies and were performed by three independent examiners. (3) Results. A total of 1383 records were identified with the initial search strategies, but only 25 full texts + five abstracts clinical studies were kept after the recruitment criteria screening. The technical details, advantages, and limitations of the techniques were illustrated. (4) Conclusion. Within the limitations of the present review, it would be merely justified that immediate dental implant placement in conjunction with the socket-shield technique can be a promising strategy for dental implant therapy.

pH Evaluation over a Period of 6 months of Two-bottle Water-based Self-etching Primers: An In Vitro Study.

AIM AND OBJECTIVE: The objective of this study was to monitor the pH stability over a period of 6 months of two-bottle self-etching (SE) primers. MATERIALS AND METHODS: Four commercially available two-bottle SE primer solutions, Adhese SE (Ivoclar Vivadent; Schaan, Liechtenstein), Clearfil SE (Kuraray; Tokyo, Japan), Contax Primer (DMG; Hamburg, Germany), and Enabond SE (Micerium; Avegno (Ge), Italy), containing water as the main solvent were selected. The pH values during a 6-month storage period at intermittent temperature were daily measured by means of a microprocessor-based pH/temperature meter and hence recorded, tabulated, and analyzed. RESULTS: The mean values of overall pH measurements and standard deviation for Adhese SE, Clearfil SE, Contax Primer, and Enabond SE are, respectively, 1.70 (±0.01), 1.72 (±0.01), 1.20 (±0.01), 1.80 (±0.01). One-way ANOVA did not detect any significant change of the mean pH values of all measurements over time. CONCLUSION: The conventional 6-months storage did not affect the pH values of the water-containing primers of two-bottle SE adhesives. CLINICAL SIGNIFICANCE: This study provides evidence that conventional storage under adequate conditions did not affect the pH values of the water-containing primers of two-bottle SE adhesives with different monomer formulations. Clinicians may rely on the known pH value of the selected SE adhesive during shelf-life.

Marginal quality of a full-body bulk-fill composite placed with an universal adhesive system in etch-and-rinse and self-etch mode: An in vitrostudy.

BACKGROUND: Marginal seal of a nanohybrid bulk-fill composite compared to a nanohybrid conventional composite, using a universal adhesive (UA) applied in etch-and-rinse (ER) and self-etch (SE) mode was investigated. MATERIAL AND METHODS: Thirty-six intact molars were selected and two standardized cavities in each tooth were prepared and allocated into four groups according to restorative material and etching strategy. All samples were placed in a 1% methylene blue solution for 24 h, then cut in the middle of the restorations obtaining two parts (n=144) and used for microscopic evaluation (50x) for dye penetration measurements. RESULTS: The data were analysed by ANOVA and Tukey post-hoc test (p<0.05). Marginal seal was influenced by adhesive strategy (p<0.05) but not from the composite used (p>0.05). CONCLUSIONS: Simplified restorations with nanohybrid bulk-fill composite showed comparable marginal leakage to incrementally placed nanohybrid composite. The UA used with a ER technique resulted in better marginal seal irrespective of the restorative material used. Key words:Bulk-fill composite, universal adhesive, self-etching, etch-and-rinse, marginal seal.

Free Gingival-Bone Graft in the Anterior Maxilla: A Clinical Case Report.

AIM: To present the healing, development, and long-term clinical results after a combined gingival-bone graft as an alternative treatment for the management of critical extraction sites in the esthetic zone. BACKGROUND: To enhance the knowledge of in vivo soft and hard tissue remodeling, in this case report, we observed the healing, development, and long-term clinical results after a case of a combined gingival-bone graft as an alternative treatment for the management of critical extraction sites. CASE DESCRIPTION: Autogenous grafts of gingival and bone tissue were placed in a 56-year-old female patient, where a hopeless upper left central incisor with an evident loss of both the buccal and the palatal bony plates and with endodontic problems was due for extraction. In order to obtain enough autogenous tissue for filling the defect, a cylindrical free gingival and bone graft was retrieved from the retromolar area with a trephine drill, to obtain hard and soft tissues for grafting the postextraction defect. After 6 months, following soft tissue maturation and once esthetic and natural gingival contours were achieved, the surgical site was prosthetically restored with a porcelain fused to a metal bridge and scheduled for regular follow-up. CONCLUSION: No complications were observed either from the donor site or from the recipient site. The post-treatment result was esthetically pleasing, based upon successful architectural stability of both hard and soft tissues. Although more studies are needed to confirm the beneficial use of this approach, the procedure can be considered a viable option in the management of soft and hard tissue remodeling in esthetically compromised cases. CLINICAL SIGNIFICANCE: The gingival-bone graft may be considered as an alternative treatment for the management of critical extraction sites in the esthetic area. How to cite this article: Signore A, Stepanov M, Angelis ND, et al. Free Gingival-Bone Graft in the Anterior Maxilla: A Clinical Case Report. J Contemp Dent Pract 2021;22(5):568-571.

Experimental and Clinical Applications of Red and Near-Infrared Photobiomodulation on Endothelial Dysfunction: A Review.

BACKGROUND: Under physiological conditions, endothelial cells are the main regulator of arterial tone homeostasis and vascular growth, sensing and transducing signals between tissue and blood. Disease risk factors can lead to their unbalanced homeostasis, known as endothelial dysfunction. Red and near-infrared light can interact with animal cells and modulate their metabolism upon interaction with mitochondria's cytochromes, which leads to increased oxygen consumption, ATP production and ROS, as well as to regulate NO release and intracellular Ca2+ concentration. This medical subject is known as photobiomodulation (PBM). We present a review of the literature on the in vitro and in vivo effects of PBM on endothelial dysfunction. METHODS: A search strategy was developed consistent with the PRISMA statement. The PubMed, Scopus, Cochrane, and Scholar electronic databases were consulted to search for in vitro and in vivo studies. RESULTS: Fifty out of >12,000 articles were selected. CONCLUSIONS: The PBM can modulate endothelial dysfunction, improving inflammation, angiogenesis, and vasodilatation. Among the studies, 808 nm and 18 J (0.2 W, 2.05 cm2) intracoronary irradiation can prevent restenosis as well as 645 nm and 20 J (0.25 W, 2 cm2) can stimulate angiogenesis. PBM can also support hypertension cure. However, more extensive randomised controlled trials are necessary.

Mitochondrial Bioenergetic, Photobiomodulation and Trigeminal Branches Nerve Damage, What's the Connection? A Review.

BACKGROUND: Injury of the trigeminal nerve in oral and maxillofacial surgery can occur. Schwann cell mitochondria are regulators in the development, maintenance and regeneration of peripheral nerve axons. Evidence shows that after the nerve injury, mitochondrial bioenergetic dysfunction occurs and is associated with pain, neuropathy and nerve regeneration deficit. A challenge for research is to individuate new therapies able to normalise mitochondrial and energetic metabolism to aid nerve recovery after damage. Photobiomodulation therapy can be an interesting candidate, because it is a technique involving cell manipulation through the photonic energy of a non-ionising light source (visible and NIR light), which produces a nonthermal therapeutic effect on the stressed tissue. METHODS: The review was based on the following questions: (1) Can photo-biomodulation by red and NIR light affect mitochondrial bioenergetics? (2) Can photobiomodulation support damage to the trigeminal nerve branches? (preclinical and clinical studies), and, if yes, (3) What is the best photobiomodulatory therapy for the recovery of the trigeminal nerve branches? The papers were searched using the PubMed, Scopus and Cochrane databases. This review followed the ARRIVE-2.0, PRISMA and Cochrane RoB-2 guidelines. RESULTS AND CONCLUSIONS: The reliability of photobiomodulatory event strongly bases on biological and physical-chemical evidence. Its principal player is the mitochondrion, whether its cytochromes are directly involved as a photoacceptor or indirectly through a vibrational and energetic variation of bound water: water as the photoacceptor. The 808-nm and 100 J/cm2 (0.07 W; 2.5 W/cm2; pulsed 50 Hz; 27 J per point; 80 s) on rats and 800-nm and 0.2 W/cm2 (0.2 W; 12 J/cm2; 12 J per point; 60 s, CW) on humans resulted as trustworthy therapies, which could be supported by extensive studies.

Photobiomodulation and Oxidative Stress: 980 nm Diode Laser Light Regulates Mitochondrial Activity and Reactive Oxygen Species Production.

Photobiomodulation with 808 nm laser light electively stimulates Complexes III and IV of the mitochondrial respiratory chain, while Complexes I and II are not affected. At the wavelength of 1064 nm, Complexes I, III, and IV are excited, while Complex II and some mitochondrial matrix enzymes seem to be not receptive to photons at that wavelength. Complex IV was also activated by 633 nm. The mechanism of action of wavelengths in the range 900-1000 nm on mitochondria is less understood or not described. Oxidative stress from reactive oxygen species (ROS) generated by mitochondrial activity is an inescapable consequence of aerobic metabolism. The antioxidant enzyme system for ROS scavenging can keep them under control. However, alterations in mitochondrial activity can cause an increment of ROS production. ROS and ATP can play a role in cell death, cell proliferation, and cell cycle arrest. In our work, bovine liver isolated mitochondria were irradiated for 60 sec, in continuous wave mode with 980 nm and powers from 0.1 to 1.4 W (0.1 W increment at every step) to generate energies from 6 to 84 J, fluences from 7.7 to 107.7 J/cm2, power densities from 0.13 to 1.79 W/cm2, and spot size 0.78 cm2. The control was equal to 0 W. The activity of the mitochondria's complexes, Krebs cycle enzymes, ATP production, oxygen consumption, generation of ROS, and oxidative stress were detected. Lower powers (0.1-0.2 W) showed an inhibitory effect; those that were intermediate (0.3-0.7 W) did not display an effect, and the higher powers (0.8-1.1 W) induced an increment of ATP synthesis. Increasing the power (1.2-1.4 W) recovered the ATP production to the control level. The interaction occurred on Complexes III and IV, as well as ATP production and oxygen consumption. Results showed that 0.1 W uncoupled the respiratory chain and induced higher oxidative stress and drastic inhibition of ATP production. Conversely, 0.8 W kept mitochondria coupled and induced an increase of ATP production by increments of Complex III and IV activities. An augmentation of oxidative stress was also observed, probably as a consequence of the increased oxygen consumption and mitochondrial isolation experimental conditions. No effect was observed using 0.5 W, and no effect was observed on the enzymes of the Krebs cycle.

Xerostomia and hyposalivation in patients with obstructive sleep apnoea.

OBJECTIVE: (a) To report the xerostomia prevalence and severity in patients with obstructive sleep apnoea (OSA). (b) To assess the saliva pH in patients with OSA. DESIGN: Simultaneous cohort observational clinical study. SETTING: In Sleep Medicine Centre at Lomonosov Moscow State University from March to June 2019. PARTICIPANTS: The study was conducted on 30 patients with OSA aged from 35 to 65 years. MAIN OUTCOMES MEASURES: The diagnosis of sleep apnoea was made after standard polysomnography using the Domino programme. The severity of OSA was indicated using the Apnoea-Hypopnea Index. Xerostomia was evaluated using Fox's test. Hyposalivation was evaluated by measurement of salivary flow rate. Determination of the saliva pH was carried out with a pH metre. Statistical analysis was performed by one-way ANOVA and Tukey-Kramer multi-comparison test. RESULTS: Twenty-two out of 30 (73.3%) patients were diagnosed with "dry mouth". Hyposalivation was observed in 6 out of 30 (20%). Dry mouth on awakening was observed in 60.0%, 72.7% and 88.9% of patients with mild, moderate and severe OSA, respectively. The average salivary flow rate was 0.28 mL/min, 0.24 mL/min and 0.14 mL/min, respectively. The average pH value in patients with mild, moderate and severe apnoea was 6.40 ± 0.017, 6.15 ± 0.27 and 5.87 ± 0.24, respectively. CONCLUSIONS: In patient with mild and moderate OSA, the saliva amount and rate are similar (P > .05). With the increase of OSA severity, both these parameters change (P < .001). The acidity of the saliva was correlated with the level of OSA, and it statistically increased with the increment of the OSA severity (P < .05-P < .001).