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 Novel Therapeutic Approach of 980 nm Photobiomodulation Delivered with Flattop Beam Profile in Management of Recurrent Aphthous Stomatitis in Paediatrics and Adolescents-A Case Series with 3-Month Follow-Up

Background/Objectives: Recurrent aphthous stomatitis (RAS) is one of the most common oral mucosal lesions and a very debilitating lesion, especially in paediatric and adolescent patients. The current pharmacotherapy offers a pain relief but not without side effects, and therefore photobiomodulation (PBM) can be an alternative therapy. To the authors' best knowledge, no published study has explored the efficacy of λ 980 nm laser PBM in the management of all RAS subtypes in paediatric and adolescent patients, and therefore, this prospective observational clinical study was conducted to bridge this gap by evaluating λ 980 nm laser PBM efficacy in symptomatic RAS management in paediatric and adolescent patients. The objectives were to evaluate (1) pain intensity alleviation; (2) wound healing rate; (3) wound size closure; (4) a complete resolution; (5) evidence of recurrence; and (6) patients' treatment satisfaction. Methods: The study's variables were assessed at the following timepoints: T0: pre-treatment; T1: immediately after first PBM session; T2: 5 hours (h) post first PBM session (via telephone call); T3: immediately after second PBM session (three days post first PBM session); T4: three-day follow-up (after complete PBM treatments); T5: two-week follow-up; and T6: three-month follow-up. The following PBM dosimetry and treatment protocols were employed: λ 980 nm; 300 mW; 60 s; 18 J; CW; flattop beam profile of 1 cm2 spot size; 18 J/cm2; and twice-a-week irradiation (72 h interval). Results: At T1, significant immediate pain intensity relief was reported. 33.33% recorded "4" and 66.67% reported "5" on the quantitative numeric pain intensity scale (NPIS), and this continued to improve significantly (83.33%) at T2. All the subjects reported "0" on the NPIS at T3, T4, T5 and T6. There was a significant reduction in the lesion surface area (>50% complete healing) at T3 compared to T0. Complete healing (100%) with no evidence of scarring and lesion recurrence observed at T4, T5 and T6. Very good patients' satisfaction was reported at all timepoints. Conclusions: This is the first report demonstrating λ980 nm efficacy in all RAS subtype management in paediatric and adolescent patients with a 3-month follow-up, whereby its PBM dosimetry and treatment protocols were effective from scientific and practical standpoints, and hence multicentre RCTs with large data are warranted to validate its reproducibility and to enrich the knowledge of PBM application in all RAS subtypes.

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.

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.

Feasibility and Safety of Adopting a New Approach in Delivering a 450 nm Blue Laser with a Flattop Beam Profile in Vital Tooth Whitening. A Clinical Case Series with an 8-Month Follow-Up

A prospective observational case series included six patients who presented with discoloured upper and lower teeth extending from the right second premolar to the left second premolar. The photoactivation dosimetry and treatment protocol were as follows: λ 450 nm, 1 W, CW; flattop beam profile; 1 cm2; 15 J/spot; 10 irradiated spots; an irradiation time of 15 s/spot; three whitening cycles in a single session. Blanc One ULTRA+ was the bleaching agent. A visual analogue scale (VAS) was utilised to evaluate the pain intensity and dental hypersensitivity during treatment immediately after complete treatment (T1), 24 h (T2), and 8 h (T3) postoperatively, and at an 8-month follow-up timepoint (T4), whereas the dental colour shade change was assessed using the VITA colour shade guide pre-treatment (T0), T1, and T4. The Gingival index and modified Wong Baker faces scale were utilised to evaluate gingival inflammation and patients' treatment satisfaction, respectively. Our findings revealed a reduction in the dental colour shade of the six cases between 2 and 10- fold (average of 3.5-fold) at T1 and maintained at T4, indicating significant improvement in the colour shade change with optimal outcomes. The percentage of this improvement for all the patients was ranged between 16.6% and 33.3%. At all timepoints, a "0" score was provided for pain intensity, dental hypersensitivity, and gingival inflammation. Our study demonstrates the feasibility and safety of a λ 450 nm laser delivered with a flattop handpiece to achieve optimal whitening outcomes without adverse effects. This offers a useful guide for dental clinicians for vital in-office tooth whitening. Extensive clinical studies with large data are warranted to validate our study protocol.

Evaluation of Sterify Gel as an Adjunctive Treatment to Scaling and Root Planing in Promoting Healing of Periodontal Pockets: A Split-Mouth Randomized Controlled Trial

Background

Periodontal disease is a common infectious disease that leads to the destruction of tooth-supporting structures. Current treatments, such as scaling and root planing (SRP), have limitations in deep and complex pockets, and antibiotic use carries the risk of resistance. Sterify Gel, a medical device composed of polyvinyl polymers, hydroxytyrosol, nisin, and magnesium ascorbyl phosphate, offers a new approach to periodontal care. This study aims to evaluate the safety and efficacy of Sterify Gel as an adjunctive treatment to SRP in promoting the healing of periodontal pockets.

Methods

The study includes 34 patients with moderate to advanced chronic periodontal disease. Randomization assigned one site for SRP alone (control) and the other site for SRP with Sterify Gel (treatment). Periodontal parameters were evaluated at baseline, 1, 2, and 3 months after treatment bacterial contamination was assessed through quantitative PCR at baseline and 3 months after treatment. Statistical analysis was conducted using ANOVA and Wilcoxon test.

Results

Treatment with Sterify Gel and SRP demonstrated significant improvements in pocket depth, gingival recession, and clinical attachment level compared with SRP alone. Bleeding and plaque indexes, pain perception, tooth mobility, and furcations showed no significant differences between the two groups. The treatment group showed a reduction in bacterial contamination at 3 months.

Conclusions

Sterify Gel in combination with SRP shows the potential for improving periodontal health by promoting healing and reducing periodontal pockets. It may offer benefits in preventing bacterial recolonization and reducing reliance on antibiotics.

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.

10,600 nm High Level-Laser Therapy Dosimetry in Management of Unresponsive Persistent Peripheral Giant Cell Granuloma to Standard Surgical Approach: A Case Report with 6-Month Follow-Up

Peripheral giant cell granuloma (PGCG) is a non-neoplastic, tumour-like reactive lesion that exclusively involves the gingiva and/or the alveolar crest. The surgical approach with a scalpel has been the golden standard of treatment for PGCG, but the scientific literature reports a high rate of lesion recurrence. Hence, this unique case report aimed to evaluate the efficacy of λ 10,600 nm high-level laser therapy (HLLT) in eradicating persistent, aggressive, and recurrent PGCG that failed to respond to standard surgical treatment. A fit and healthy thirty-four-year-old Caucasian male presented with a two-month history of recurrent episodes of an oral mucosal lesion involving the buccal and lingual interdental papillae between the lower right second premolar (LR5) and lower right first molar (LR6), which was surgically excised with a scalpel three times previously. A λ 10,600 nm-induced HLLT was chosen as a treatment modality at a lower peak power of 1.62 W, measured with a power metre, emitted in gated emission mode (50% duty cycle), whereby the average output power reaching the target tissue was 0.81 W. The spot size was 0.8 mm. Ninety seconds was the total treatment duration, and the total energy density was 7934.78 J/cm2. Patient self-reporting outcomes revealed minimal to no post-operative complications. Initial healing was observed on the 4th day of the post-laser treatment, and a complete healing occurred at two-weeks post-operatively. The histological analysis revealed PGCG. This unique case report study demonstrated the efficacy of λ 10,600 nm-induced HLLT and its superiority to eradicate persistent aggressive PGCG over the standard surgical approach with minimal to no post-operative complications, accelerating wound healing beyond the physiological healing time associated with no evidence of PGCG recurrence at the six-month follow-up timepoint. Based on the significant findings of this unique study and the results of our previous clinical studies, we can confirm the validity and effectiveness of our standardised λ 10,600 nm laser dosimetry-induced HLLT and treatment protocol in achieving optimal outcomes. Randomised controlled clinical trials with large data comparing λ 10,600 nm with our dosimetry protocol to the standard surgical treatment modality at long follow-up timepoints are warranted.

In Vitro Assessment of SWEEPS and Antimicrobial Photodynamic Therapy Alone or in Combination for Eradicating Enterococcus faecalis Biofilm in Root Canals

OBJECTIVES

This study investigates the efficacy of antimicrobial photodynamic therapy (aPDT) using riboflavin and a blue diode laser (BDL), combined with shock wave-enhanced emission photoacoustic streaming (SWEEPS), against Enterococcus faecalis.

MATERIALS AND METHODS

A total of 48 extracted single-rooted human teeth were used. The root canals were instrumented, sealed at their apices, had the smear layer removed, and then underwent autoclave sterilization. Subsequently, each canal was inoculated with E. faecalis bacterial suspension and allowed to incubate for ten days. After confirming the presence of biofilms through scanning electron microscopy (SEM) in three teeth, the remaining teeth were randomly allocated into nine groups, each containing five teeth: control, 5.25% sodium hypochlorite (NaOCl), BDL, SWEEPS + normal saline, SWEEPS + NaOCl, riboflavin, riboflavin + SWEEPS, riboflavin + BDL, and riboflavin + BDL + SWEEPS. After the treatment, the numbers of colony-forming units (CFUs)/mL were calculated. The data were analysed using one-way ANOVA followed by Tukey's test for comparisons.

RESULTS

All groups, with the exception of the BDL group, exhibited a significant reduction in E. faecalis CFU/mL when compared to the control group (p < 0.001). The difference in CFU/mL value between riboflavin + BDL + SWEEPS and riboflavin + SWEEPS was significant (p = 0.029), whereas there was no significant difference between riboflavin + BDL + SWEEPS and riboflavin + BDL (p = 0.397). Moreover, there was no statistically significant difference between the riboflavin + SWEEPS group and the riboflavin + BDL group (p = 0.893).

CONCLUSIONS

The results demonstrated that combining the SWEEPS technique with riboflavin as a photosensitizer activated by BDL in aPDT effectively reduced the presence of E. faecalis in root canals.

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.

Innovative Nanostructured Fillers for Dental Resins: Nanoporous Alumina and Titania Nanotubes

The possibility of improving dental restorative materials is investigated through the addition of two different types of fillers to a polymeric resin. These fillers, consisting of porous alumina and TiO₂ nanotubes, are compared based on their common physicochemical properties on the nanometric scale. The aim was to characterize and compare the surface morphological properties of composite resins with different types of fillers using analytical techniques. Moreover, ways to optimize the mechanical, surface, and aesthetic properties of reinforced polymer composites are discussed for applications in dental treatments. Filler-reinforced polymer composites are the most widely used materials in curing dental pathologies, although it remains necessary to optimize properties such as mechanical resistance, surface characteristics, and biocompatibility. Anodized porous alumina nanoparticles prepared by electrochemical anodization offer a route to improve mechanical properties and biocompatibility as well as to allow for the controlled release of bioactive molecules that can promote tissue integration and regeneration. The inclusion of TiO₂ nanotubes prepared by hydrothermal treatment in the resin matrix promotes the improvement of mechanical and physical properties such as strength, stiffness, and hardness, as well as aesthetic properties such as color stability and translucency. The surface morphological properties of composite resins with anodized porous alumina and TiO₂ nanotube fillers were characterized by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), and X-ray chemical analysis. In addition, the stress-strain behavior of the two composite resins is examined in comparison with enamel and dentin.

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.

Prevention of Dry Socket with Ozone Oil-Based Gel after Inferior Third Molar Extraction: A Double-Blind Split-Mouth Randomized Placebo-Controlled Clinical Trial

Tooth extraction is followed by a sequence of elaborate local changes affecting hard and soft tissues. Dry socket (DS) can occur as intense pain around and in the extraction site, with an incidence from 1–4% after generic tooth extraction to 45% for mandibular third molars. Ozone therapy has gained attention in the medical field because of its success in the treatment of various diseases, its biocompatible properties and its fewer side effects or discomfort than drugs. To investigate the preventive effect of the sunflower oil-based ozone gel Ozosan® (Sanipan srl, Clivio (VA), Italy) on DS, a double-blind split-mouth randomized placebo-controlled clinical trial was conducted according to the CONSORT guidelines. Ozosan® or the placebo gel were put in the socket, and the gels were washed off 2 min later. In total, 200 patients were included in our study. The patient population comprised 87 Caucasian males and 113 Caucasian females. The mean age of the included patients was 33.1 ± 12.4 years. Ozosan reduced the incidence of DS after inferior third molar extraction from 21.5% of the control to 2% (p < 0.001). Concerning the dry socket epidemiology, the incidence was not significantly correlated with gender, smoking or mesioangular, vertical or distoangular Winter’s classification. Post hoc power calculation showed a power of 99.8% for this data, with alpha = 0.001.

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.

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.

Comparison of the Clinical Outcomes of Titanium and Zirconia Implant Abutments: A Systematic Review of Systematic Reviews

Background: Dental implants are widely used and in order to answer to esthetic demands, zirconia has been introduced as an abutment material as an alternative to titanium. Several studies have been published on this topic, but the results have been often inconsistent. The objective of the present study is to systematically analyze the existing literature comparing clinical outcomes of titanium and zirconia implant abutments. The study was designed as a systematic review of systematic reviews. Methods: This systematic review is in accordance with the Transparent Reporting of Systematic Reviews and Meta-analyses. A MEDLINE/PubMed, Cochrane Database of Systematic Reviews and SCOPUS literature search was performed up to and including June 2021. Data were extracted independently by two reviewers and tAMSTAR2 was used to assess the quality of the systematic reviews. Results: The electronic search identified 1146 papers, and 175 duplicates were removed. After manual screening, 954 studies were excluded and the final analysis was conducted on 11 papers. Both mechanical and esthetic outcomes and biological complications were analyzed. Conclusions: It can be concluded that titanium abutments have a better mechanical resistance than zirconia ones. Plaque accumulation is reported to be slightly higher on titanium but without any significant inflammatory process. The esthetic outcomes seem to be more related to the thickness (>3 mm) of the soft tissues than to the abutment material.

Outpatient Oral Neuropathic Pain Management with Photobiomodulation Therapy: A Prospective Analgesic Pharmacotherapy-Paralleled Feasibility Trial

Neuropathic pain (NP) can be challenging to treat effectively as analgesic pharmacotherapy (MED) can reduce pain, but the majority of patients do not experience complete pain relief. Our pilot approach is to assess the feasibility and efficacy of an evidence-based photobiomodulation (PBM) intervention protocol. This would be as an alternative to paralleled standard analgesic MED for modulating NP intensity-related physical function and quality of life (QoL) prospectively in a mixed neurological primary burning mouth syndrome and oral iatrogenic neuropathy study population (n = 28). The study group assignments and outcome evaluation strategy/location depended on the individual patient preferences and convenience rather than on randomisation. Our prospective parallel study aimed to evaluate the possible pre/post-benefit of PBM and to allow for a first qualitative comparison with MED, various patient-reported outcome measures (PROMs) based on Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT-II) were used for up to a nine-month follow-up period in both intervention groups (PBM and MED). The PBM protocol applied to the PBM group was as follows: λ810 nm, 200 mW, 0.088 cm2, 30 s/point, 9 trigger and affected points, twice a week for five consecutive weeks, whereas the MED protocol followed the National Institute of Clinical Excellence (NICE) guidelines. Our results showed that despite the severe and persistent nature of the symptoms of 57.50 ± 47.93 months at baseline in the PBM group, a notably rapid reduction in PISmax on VAS from 7.6 at baseline (T0) to 3.9 at one-month post-treatment (T3) could be achieved. On the other hand, mean PISmax was only reduced from 8.2 at baseline to 6.8 at T3 in the MED group. Our positive PBM findings furthermore support more patients' benefits in improving QoL and functional activities, which were considerably impaired by NP such as: eating, drinking and tasting, whereas the analgesic medication regimens did not. No adverse events were observed in both groups. To the best knowledge of the authors, our study is the first to investigate PBM efficacy as a monotherapy compared to the gold standard analgesic pharmacotherapy. Our positive data proves statistically significant improvements in patient self-reported NP, functionality, psychological profile and QoL at mid- and end-treatment, as well as throughout the follow-up time points (one, three, six and nine months) and sustained up to nine months in the PBM group, compared to the MED group. Our study, for the first time, proves the efficacy and safety of PBM as a potent analgesic in oral NP and as a valid alternative to the gold standard pharmacotherapy approach. Furthermore, we observed long-term pain relief and functional benefits that indicate that PBM modulates NP pathology in a pro-regenerative manner, presumably via antioxidant mechanisms.

Steering the multipotent mesenchymal cells towards an anti-inflammatory and osteogenic bias via photobiomodulation therapy: How to kill two birds with one stone

The bone marrow-derived multipotent mesenchymal cells (MSCs) have captured scientific interest due to their multi-purpose features and clinical applications. The operational dimension of MSCs is not limited to the bone marrow reservoir, which exerts bone-building and niche anabolic tasks; they also meet the needs of quenching inflammation and restoring inflamed tissues. Thus, the range of MSC activities extends to conditions such as neurodegenerative diseases, immune disorders and various forms of osteopenia. Steering these cells towards becoming an effective therapeutic tool has become mandatory. Many laboratories have employed distinct strategies to improve the plasticity and secretome of MSCs. We aimed to present how photobiomodulation therapy (PBM-t) can manipulate MSCs to render them an extraordinary anti-inflammatory and osteogenic instrument. Moreover, we discuss the outcomes of different PBM-t protocols on MSCs, concluding with some perplexities and complexities of PBM-t in vivo but encouraging and feasible in vitro solutions.

808-nm Photobiomodulation Affects the Viability of a Head and Neck Squamous Carcinoma Cellular Model, Acting on Energy Metabolism and Oxidative Stress Production

Photobiomodulation (PBM) is a form of low-dose light therapy that acts through energy delivery from non-ionizing sources. During the recent two decades, there has been tremendous progress with PBM acceptance in medicine. However, PBM effects on potential stimulation of existing malignant or pre-malignant cells remain unknown. Thus, the primary endpoint was to assess the safety of PBM treatment parameters on head and neck squamous cell carcinoma (HNSCC) proliferation or survival. The secondary endpoint was to assess any putative anti-cancer effects of PBM treatments. Cell viability, energy metabolism, oxidative stress, and pro- and anti-apoptotic markers expression were investigated on a Human Head and Neck Squamous Cell Carcinoma cellular model (OHSU-974 FAcorr cell line). PBM therapy was administered through the 810 nm diode laser (GaAlAs) device (Garda Laser, 7024 Negrar, Verona, Italy) at the powers of 0, 0.25, 0.50, 0.75, 1.00, or 1.25 W in continuous wave (CW) mode for an exposure time of 60 s with a spot-size of 1 cm² and with a distance of 1.86 cm from the cells. Results showed that 810-nm PBM affected oxidative phosphorylation in OHSU-971 FAcorr, causing a metabolic switch to anaerobic glycolysis. In addition, PBM reduced the catalase activity, determining an unbalance between oxidative stress production and the antioxidant defenses, which could stimulate the pro-apoptotic cellular pathways. Our data, at the parameters investigated, suggest the safeness of PBM as a supportive cancer therapy. Pre-clinical and clinical studies are necessary to confirm the in vitro evidence.

Role of Photobiomodulation Therapy in Neurological Primary Burning Mouth Syndrome. A Systematic Review and Meta-Analysis of Human Randomised Controlled Clinical Trials

Mitochondrial homeostasis is crucial for energy production and neuronal survival in neurological primary burning mouth syndrome (npBMS). Photobiomodulation therapy (PBMT) has been utilised in npBMS management, however, its role of intervention remains controversial. The aim of this systematic review and meta-analysis of CRD 42020198921 PROSPERO registration reference was to oversee and determine the efficacy of PBMT in patients with npBMS, identifying the gaps and bridge them by proposing recommendations for future studies purposes. PRISMA guidelines and Cochrane Collaboration recommendations followed. Various search engines employed to analyse a total of 351 studies of which 12 were included. A wide range of utilised PBM wavelengths was between 635-980 nm and the power output ranged between 30 mW and 4000 mW. A high risk of bias (RoB) was noted in 7 out of 12 included studies (58.3%), as results of qualitative analysis. Meta-analysis findings of 4 out of 12 studies showed statistically significant intergroup differences (SSID) for visual analogue scale (VAS) values (MD = -1.47; 95% CI = -2.40 to -0.53; Z = 3.07 (p = 0.002) whereas meta-analysis on 5 out of 12 studies revealed SSID for anxiety/depression and quality of life (MD = -1.47; 95% CI = -2.40 to -0.53; Z = 3.07 (p = 0.002), favouring PBMT group to the control treatment strategies. Despite the inconsistency and diversity in PBM parameters (wavelength, power, light source, spot size, emission mode, energy per point, total energy) and treatment protocols (exposure time, number of sessions, time interval between sessions, treatment duration)-majority of the included studies showed positive PBM results. The high RoB and meta-analytical heterogeneity in the eligible studies warrant the necessity to perform well-designed and robust RCTs after acknowledging the drawbacks of the available scientific literature and addressing our suggested recommendations highlighted in our review.

Utilisation of an 810 nm diode laser for surgical management of oral soft tissues related to orthodontic treatment: A case series

The present case series demonstrates the efficacy of an 810 nm diode laser for the surgical management of oral soft tissues related to orthodontic treatment. Three orthodontic patients aged 16-23 years underwent operculectomy, ablation of soft-tissue overgrowth over orthodontic appliance and gingivectomy along with gingival recontouring procedures, respectively, using the 810 nm diode laser. In each case, an initiated laser fibre tip was utilised to ablate the tissue at the treatment site by making a light contact with the tissue (average power output = 1-1.6 W, continuous wave emission mode, fibre diameter = 400 µm, spot size = 0.0013 cm², energy density = 124.9-199.9 J/cm², irradiance = 796-1273 W/cm², total energy dose = 300-480 J). The maximum total length of treatment was 300 s (5 min). None of the patients reported any instantaneous or delayed postoperative complications over six months. Utilisation of the 810 nm diode laser for surgical management of oral soft tissues related to orthodontic treatments can be considered safe, effective and justifiable over the conventional scalpel technique; however, it must be performed by trained and experienced clinicians only.

Efficacy of near infrared dental lasers on dentinal hypersensitivity: a meta-analysis of randomized controlled clinical trials

Conventional therapies have aimed to try to help individuals suffering with dentine hypersensitivity (DH/DHS). A relatively new approach, laser therapy claims to be beneficial while having immediate and long-lasting effect. Therefore, our analysis aims to explore the immediate and 1-month efficacy of near-infrared laser (NIR) therapy in treating dentinal hypersensitivity. A systematic literature search conducted in databases, and analysis was undertaken utilizing a meta-analysis approach. Randomized controlled clinical trials comparing near-infrared lasers and placebo/no treatment in patients (> 18 years) were included. The risk of bias for included studies was assessed using Cochrane RoB tool (for randomized studies). Random effects meta-analyses model of standardized mean differences and 95% confidence intervals were performed using RevMan 5.4 software. A comprehensive electronic and manual search yielded a total of 1081 potential articles. Following the implementation of the inclusion and exclusion criteria, a total of 6 studies were included in the analysis. Near-infrared laser therapy led to statistical significant reduction in immediate and 1-month follow-up VAS (visual analog scale) scores compared to placebo/no treatment (p < 0.05). Statistical heterogeneity across the studies was high (I²-96%). The findings suggest that near-infrared laser therapy does have a significant immediate effect in reducing dentine hypersensitivity compared to placebo/no treatment. Furthermore, this effect is not diminished and endured at 1-month follow-up.

Improving Consistency of Photobiomodulation Therapy: A Novel Flat-Top Beam Hand-Piece versus Standard Gaussian Probes on Mitochondrial Activity

The tremendous therapeutic potential of photobiomodulation therapy in different branches of medicine has been described in the literature. One of the molecular mechanisms for this treatment implicates the mitochondrial enzyme, cytochrome C oxidase. However, the efficacy and consistency of clinical outcomes with photobiomodulation treatments has been fiercely debated. This work was motivated by this need to improve photobiomodulation devices and delivery approaches. We designed a novel hand-piece with a flat-top beam profile of irradiation. We compared the beam profile versus a standard hand-piece and a fibre probe. We utilized isolated mitochondria and performed treatments at various spots within the beam, namely, the centre, left and right edge. We examined mitochondrial activity by assessing ATP synthesis with the luciferin/luciferase chemiluminescent method as a primary endpoint, while mitochondrial damage was assessed as the secondary endpoint. We observed a uniform distribution of the power density with the flat-top prototype compared to a wide Gaussian beam profile with the standard fibre and standard hand-piece. We noted increased production of ATP in the centre of all three beams with respect to the non-treated controls (p < 0.05). Both the fibre and standard hand-piece demonstrated less increase in ATP synthesis at the edges than the centre (p < 0.05). In contrast, ATP synthesis was increased homogenously in the flat-top handpiece, both in the centre and the edges of the beam. Fibre, standard hand-piece and the flat-top hand-piece prototype have discrete beam distribution characteristics. This significantly affected the mitochondrial activity with respect to their position within the treated areas. Flat-top hand-piece enhances the uniformity of photobiomodulation treatments and can improve the rigour and reproducibility of PBM clinical outcomes.

Photobiomodulation by Near-Infrared 980-nm Wavelengths Regulates Pre-Osteoblast Proliferation and Viability through the PI3K/Akt/Bcl-2 Pathway

BACKGROUND

bone tissue regeneration remains a current challenge. A growing body of evidence shows that mitochondrial dysfunction impairs osteogenesis and that this organelle may be the target for new therapeutic options. Current literature illustrates that red and near-infrared light can affect the key cellular pathways of all life forms through interactions with photoacceptors within the cells' mitochondria. The current study aims to provide an understanding of the mechanisms by which photobiomodulation (PBM) by 900-nm wavelengths can induce in vitro molecular changes in pre-osteoblasts.

METHODS

The PubMed, Scopus, Cochrane, and Scholar databases were used. The manuscripts included in the narrative review were selected according to inclusion and exclusion criteria. The new experimental set-up was based on irradiation with a 980-nm laser and a hand-piece with a standard Gaussian and flat-top beam profile. MC3T3-E1 pre-osteoblasts were irradiated at 0.75, 0.45, and 0.20 W in continuous-wave emission mode for 60 s (spot-size 1 cm²) and allowed to generate a power density of 0.75, 0.45, and 0.20 W/cm² and a fluence of 45, 27, and 12 J/cm², respectively. The frequency of irradiation was once, three times (alternate days), or five times (every day) per week for two consecutive weeks. Differentiation, proliferation, and cell viability and their markers were investigated by immunoblotting, immunolabelling, fluorescein-FragELTM-DNA, Hoechst staining, and metabolic activity assays.

RESULTS AND CONCLUSIONS

The 980-nm wavelength can photobiomodulate the pre-osteoblasts, regulating their metabolic schedule. The cellular signal activated by 45 J/cm², 0.75 W and 0.75 W/cm² consist of the PI3K/Akt/Bcl-2 pathway; differentiation markers were not affected, nor do other parameters seem to stimulate the cells. Our previous and present data consistently support the window effect of 980 nm, which has also been described in extracted mitochondria, through activation of signalling PI3K/Akt/Bcl-2 and cyclin family, while the Wnt and Smads 2/3-β-catenin pathway was induced by 55 J/cm², 0.9 W and 0.9 W/cm².

Impact of Adjunctive Diode Laser Application to Non-Surgical Periodontal Therapy on Clinical, Microbiological and Immunological Outcomes in Management of Chronic Periodontitis: A Systematic Review of Human Randomized Controlled Clinical Trials

Background

Due to the limitations of scaling and root planing (SRP) in chronic periodontitis (CP) management, research has been focused on utilising additional therapies to enhance conventional treatment methods. The present systematic review is aimed to appraise the accessible scientific evidence of in vivo human studies to establish the effectiveness of adjunctive diode (λ 808- λ 980nm) laser treatment to SRP in CP.

Methodology

This systematic review was conducted following the PRISMA statement guidelines. The review protocol is registered in PROSPERO (CRD 42021227695). The search strategies were based on structured electronic and manual (with appropriate keywords) and were conducted to collect the applicable published data on RCTs studies (in vivo human), spanning over ten years between August 2010 and August 2020. The articles were selected to address the following research focus question: “Does diode laser (λ 808- λ 980nm) therapy have superior effects as an adjunct to SPR, compared to SRP alone, in terms of clinical or microbiological or immunological profiles in the management of CP?”

Results

Fifteen articles met the eligibility criteria and are included in this review. A wide range of discrepancies and inconsistencies were shown in the outcomes of the laser and SPR treatment modality, compared to SRP alone. The data on standardised study protocol, optimal laser parameters and outcome measurements were inconclusive, and a high risk of bias in the majority of the studies observed, which are crucial in establishing a homogenous and reproducible protocol.

Conclusion

In light of the confined evidence-based data and critical evaluation of this systematic review, the efficacy of adjunctive diode laser treatment ranging between 808 and 980nm to SRP remains debatable. The observational quality of the present systematic review was emphasised after scrutinising the available data, and an attempt to propose a laser protocol for future RCTs consideration was a great challenge due to an absence of clear and standardised recommendations in delivering a reliable laser protocol which can be replicable by future investigators. RCTs with robust methodology are warranted.

Effectiveness of Antimicrobial Photodynamic Therapy in the Treatment of Periodontitis: A Systematic Review and Meta-Analysis of In Vivo Human Randomized Controlled Clinical Trials

This systematic review and meta-analysis evaluated antimicrobial photodynamic therapy (aPDT) efficacy in periodontitis. The review protocol was conducted in accordance with PRISMA statements, Cochrane Collaboration recommendations and is registered in PROSPERO (CRD 42020161516). Electronic and hand search strategies were undertaken to gather data on in vivo human RCTs followed by qualitative analysis. Differences in probing pocket depth (PPD) and clinical attachment level (CAL) were calculated with 95% confidence intervals and pooled in random effects model at three and six months. Heterogeneity was analyzed, using Q and I² tests. Publication bias was assessed by visual examination of the funnel plot symmetry. Sixty percent of 31 eligible studies showed a high risk of bias. Meta-analysis on 18 studies showed no additional benefit in split mouth studies in terms of PPD reduction (SMD 0.166; 95% CI −0.278 to 0.611; P = 0.463) and CAL gain (SMD 0.092; 95% CI −0.013 to 0.198; P = 0.088). Similar findings noted for parallel group studies; PPD reduction (SMD 0.076; 95% CI −0.420 to 0.573; P = 0.763) and CAL gain (SMD 0.056; 95% CI −0.408 to 0.552; P = 0.745). Sensitivity analysis minimized heterogeneity for both outcome variables; however, intergroup differences were not statistically significant. Future research should aim for well-designed RCTs in order to determine the effectiveness of aPDT.

Electromagnetic Dosimetry for Isolated Mitochondria Exposed to Near-Infrared Continuous-Wave Illumination in Photobiomodulation Experiments

This paper presents results on the electromagnetic field computed inside isolated mitochondria when they are exposed to near-infrared illuminations with reference to photobiomodulation experiments. The accurate calculation of the electromagnetic dose is considered to be important for a better understanding of the mechanism of interaction of light with these organelles and to improve the reliability and repeatability of the experiments. To get such results, we introduce several models. Even though they refer to a well-defined experimental setup, different models are necessary to take into account the possible different dispositions of the mitochondria, and of the differences in their dimensions and in their constitutive parameters. Different wavelengths and polarizations are considered as well. The effects of all parameters on the electromagnetic field inside mitochondria are discussed. © 2021 Bioelectromagnetics Society.

Is antimicrobial photodynamic therapy an effective treatment modality for aggressive periodontitis? A systematic review of in vivo human randomized controlled clinical trials

BACKGROUND

Limitations of scaling and root planing (SRP) have directed research to utilize additional therapies to enhance conventional techniques. The present systematic review was conducted to evaluate and present a comprehensive overview on effectiveness of antimicrobial photodynamic therapy (aPDT) in the management of aggressive periodontitis (AgP).

METHODOLOGY

The PRISMA statement guidelines and Cochrane Collaboration recommendations were followed to conduct this systematic review. The review protocol is registered in PROSPERO (CRD 42019143316). A structured electronic and manual search strategy was implied to gather the relevant published data on in vivo human RCTs from their earliest records until 31st October 2019. Relevant data was extracted from the eligible studies, analysed and impartially appraised for its quality.

RESULTS

Eleven papers met the eligibility criteria and included in this review. The data on standardized study protocol, ideal photosensitizer (PS) dye-wavelength combination, optimal parameters was inconclusive and a high risk of bias in majority of the studies noted, which are fundamental in establishing a standardized and replicable protocol.

CONCLUSION

Ultimately researchers should conduct well-designed and robust RCTs performed by trained clinicians in order to determine the effectiveness of aPDT, if any, after acknowledging the drawbacks highlighted in this systematic review.

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.

Utilization of 810 nm Diode Laser Treatment in Periodontitis as an Alternative to Surgical Debridement Approach

The efficacy of surgical periodontal may be compromised by inadequate patients' self-performed plaque control or lack of supportive periodontal therapy. This clinical case report aimed to evaluate the effectiveness of 810 nm diode laser-assisted full-mouth sulcular debridement, as a potential treatment modality in the management of chronic periodontitis along with a 12-month follow-up evaluation. Each periodontal pocket was lased within 2 mm of deepest point, using a light contact of "hot tip" of the fiber with tissue [Average power-1W, emission mode-continuous wave, in "contact", beam diameter-400 µm, spot area at tissue-0.0013 cm² , fluence-124.9 J cm^-2 , power density-796 W cm^-2 , total energy-300 J, total treatment duration-300 s (5 min)]. The patient was followed up to 12 months and did not report any immediate or delayed complications such as any sign of photothermal damage, pain, tissue swelling and deformation, bleeding and infection. 810 nm diode laser-assisted sulcular debridement at low-power settings showed overall clinical and radiographic improvements and can be deemed as a potential alternative to surgical debridement approach, in persistent moderate periodontal pockets (4-6 mm).

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.

Evaluating the marginal integrity and clinical outcome of posterior zirconia inlay-retained fixed dental prostheses: A randomized clinical trial

PURPOSE

To assess the short-term outcomes of two different conservative preparation designs for posterior zirconia inlay-retained fixed dental prostheses (IRFDPs) and to analyze the marginal integrity of such restorations.

MATERIALS AND METHODS

Thirty patients with a missing maxillary first molar participated in this study and were divided randomly into two groups: one that received abutment preparations for inlay retainers (ID group, n = 20), including a proximal box and an occlusal extension, and one that received only proximal box preparations (PB group, n = 10). Zirconia IRFDPs were bonded in position and followed up after 2 weeks, 6 months, 1 year, and then annually. The in situ restorations were duplicated utilizing a single-step putty/wash impression technique at the 2-week and 2-year follow-up visits. Restoration margins were evaluated under scanning electron microscopy, and marginal continuity was calculated as a percentage of the whole margin at the tooth-cement (TC) interface and the zirconia-cement (ZC) interface.

RESULTS

After a mean observation period of 26.2 months, all restorations were still in function. The only complication encountered was debonding of restorations; however, they were re-bonded back in place without issue. The cumulative Kaplan-Meier 2-year survival rate for the IRFDPs was 86.6%. There was a significant difference between the two groups regarding percentage of continuous margins (P < .05) after 2 years, with the percentage of continuous margins in the ID group at 92.8% and 91.5% at the TC and ZC interfaces, respectively, and in the PB group at 84.1% and 78.6% at the TC and ZC interfaces, respectively.

CONCLUSION

Zirconia-based monolithic IRFDPs can be recommended for short-term replacement of a single maxillary molar.

Flapless Surgical Approach to Extract Impacted Inferior Third Molars: A Retrospective Clinical Study

This study aimed to compare a flapless surgical approach (FSA) with a traditional envelope flap (traditional approach (TA)). Every patient was treated with two approaches: TA and FSA. The primary outcome variables were both the discomfort during the post-operative convalescence and the correct final recovery of the impacted area. The secondary outcome variable was the average duration of the surgery. Post-operative pain and oedema were recorded. The measurements of soft tissue interface toward the distobuccal edge of the second molar were taken by periodontal probe before surgery (baseline) and 8 weeks after surgery. Statistical software was used to evaluate the data; a p-value < 0.05 was considered statistically significant. Twenty-four teeth of 12 patients (six Caucasian males and six Caucasian females, aged 23 ± 4 (17-30) years) with both lower impacted third molars (Ms3) were analysed. Considering an alpha error 0.05 that sample size allows power from 0.80 to 0.90, depending on the variable evaluated. Concerning attached gingiva, oedema and pain, the linear mixed model resulted in a statistically significant difference between the TA and FSA (p = 0.003; p < 0.01; and p = 0.018, respectively). Conversely, the model did not show a difference (p = 0.322) if pocket probing depth was considered. The FSA procedure was faster (p < 0.05) than the TA procedure (17 min and 8 s (±6 s) vs. 28 min and 6 s (±4 s), respectively). The results suggest that the FSA could be a suitable option for improving the surgical removal of lower Ms3. However, additional randomized controlled trial studies are necessary to confirm the reliability of our procedure and to verify its suitability in more complex Ms3 classifications.

Understanding COVID-19 Pandemic: Molecular Mechanisms and Potential Therapeutic Strategies. An Evidence-Based Review

Initially, the SARS-CoV-2 virus was considered as a pneumonia virus; however, a series of peer reviewed medical papers published in the last eight months suggest that this virus attacks the brain, heart, intestine, nervous and vascular systems, as well the blood stream. Although many facts remain unknown, an objective appraisal of the current scientific literature addressing the latest progress on COVID-19 is required. The aim of the present study was to conduct a critical review of the literature, focusing on the current molecular structure of SARS-CoV-2 and prospective treatment modalities of COVID-19. The main objectives were to collect, scrutinize and objectively evaluate the current scientific evidence-based information, as well to provide an updated overview of the topic that is ongoing. The authors underlined potential prospective therapies, including vaccine and phototherapy, as a monotherapy or combined with current treatment modalities. The authors concluded that this review has produced high quality evidence, which can be utilized by the clinical scientific community for future reference, as the knowledge and understanding of the SARS-CoV-2 virus are evolving, in terms of its epidemiological, pathogenicity, and clinical manifestations, which ultimately map the strategic path, towards an effective and safe treatment and production of a reliable and potent vaccine.

Effects of photobiomodulation on bone defects grafted with bone substitutes: A systematic review of in vivo animal studies

A present, photobiomodulation therapy (PBMT) effectiveness in enhancing bone regeneration in bone defects grafted with or without biomaterials is unclear. This systematic review (PROSPERO, ref. CRD 42019148959) aimed to critically appraise animal in vivo published data and present the efficacy of PBMT and its potential synergistic effects on grafted bone defects. MEDLINE, CCCT, Scopus, Science Direct, Google Scholar, EMBASE, EBSCO were searched, utilizing the following keywords: bone repair; low-level laser therapy; LLLT; light emitting diode; LEDs; photobiomodulation therapy; in vivo animal studies, bone substitutes, to identify studies between 1994 and 2019. After applying the eligibility criteria, 38 papers included where the results reported according to "PRISMA." The results revealed insufficient and incomplete PBM parameters, however, the outcomes with or without biomaterials have positive effects on bone healing. In conclusion, in vivo animal studies with a standardized protocol to elucidate the effects of PBMT on biomaterials are required initially prior to clinical studies.

Effectiveness of Photobiomodulation as an Adjunct to Nonsurgical Periodontal Therapy in the Management of Periodontitis- A Systematic Review of in vivo Human Studies

Photobiomodulation therapy (PBMT) has anti-inflammatory, analgesic and regenerative properties. This systematic review aimed to critically appraise the published data of in vivo human randomized clinical trials (RCTs), and present a comprehensive overview of the efficacy of PBMT, as an adjunct to the nonsurgical periodontal therapy (NSPT) in the management of periodontitis. The systematic review protocol is registered in the Prospective Register Of Systematic Reviews (PROSPERO) (www.crd.york.ac.uk/PROSPERO/; ref CRD 42020169108). With the help of the appropriate key words, structured electronic and manual search strategies were applied to gather the relevant published data on in vivo human RCTs based on this topic. Seventeen papers that met the eligibility criteria were included in this review and subjected to a qualitative assessment. Current evidence lacks adequate information regarding the photobiomodulation (PBM) dosimetry, which is fundamental in establishing a standardized and replicable protocol for future researches. Furthermore, substantial discrepancies in the study methodology and a high risk of bias, arising from the majority of the included papers, abet to the inferior quality of these studies. Ultimately, there is an urgent necessity to conduct further well-designed RCTs in order to determine the effectiveness of PBMT, if any, by taking into consideration the abovementioned confounding factors.

The effects of 808-nm near-infrared laser light irradiation on actin cytoskeleton reorganization in bone marrow mesenchymal stem cells

Tailoring the cell organelles and thus changing cell homeostatic behavior has permitted the discovery of fascinating metabolic features enabling enhanced viability, differentiation, or quenching inflammation. Recently, photobiomodulation (PBM) has been accredited as an effective cell manipulation technique with promising therapeutic potential. In this prospective, in vitro results revealed that 808-nm laser light emitted by a hand-piece with a flat-top profile at an irradiation set up of 60 J/cm2 (1 W, 1 W/cm²; 60 s, continuous wave) regulates bone marrow stromal cell (BMSC) differentiation toward osteogenesis. Considering the importance of actin cytoskeleton reorganization, which controls a range of cell metabolic activities, comprising shape change, proliferation and differentiation, the aim of the current work is to assess whether PBM therapy, using a flat-top hand-piece at higher-fluence irradiation on BMSCs, is able to switch photon signals into the stimulation of biochemical/differentiating pathways involving key activators that regulate de novo actin polymerization. Namely, for the first time, we unearthed the role of the flat-top hand-piece at higher-fluence irradiation on cytoskeletal characteristics of BMSCs. These novel findings meet the needs of novel therapeutically protocols provided by laser treatment and the manipulation of BMSCs as anti-inflammatory, osteo-inductive platforms.

Phototherapy as a Rational Antioxidant Treatment Modality in COVID-19 Management; New Concept and Strategic Approach: Critical Review

The COVID-19 pandemic has taken the entire globe by storm. The pathogenesis of this virus has shown a cytokine storm release, which contributes to critical or severe multi-organ failure. Currently the ultimate treatment is palliative; however, many modalities have been introduced with effective or minimal outcomes. Meanwhile, enormous efforts are ongoing to produce safe vaccines and therapies. Phototherapy has a wide range of clinical applications against various maladies. This necessitates the exploration of the role of phototherapy, if any, for COVID-19. This critical review was conducted to understand COVID-19 disease and highlights the prevailing facts that link phototherapy utilisation as a potential treatment modality for SARS-CoV-2 viral infection. The results demonstrated phototherapy's efficacy in regulating cytokines and inflammatory mediators, increasing angiogenesis and enhancing healing in chronic pulmonary inflammatory diseases. In conclusion, this review answered the following research question. Which molecular and cellular mechanisms of action of phototherapy have demonstrated great potential in enhancing the immune response and reducing host-viral interaction in COVID-19 patients? Therefore, phototherapy is a promising treatment modality, which needs to be validated further for COVID-19 by robust and rigorous randomised, double blind, placebo-controlled, clinical trials to evaluate its impartial outcomes and safety.

Photobiomodulation Therapy in Oral Mucositis and Potentially Malignant Oral Lesions: A Therapy Towards the Future

Photobiomodulation therapy (PBMT) is an effective treatment modality, which has the significant advantage of enhancing a patient’s quality of life (QoL) by minimising the side effects of oral cancer treatments, as well as assisting in the management of potentially cancerous lesions. It is important to note that the major evidence-based documentation neither considers, nor tackles, the issues related to the impact of PBMT on tumour progression and on the downregulation of cellular proliferation improvement, by identifying the dose- and time-dependency. Moreover, little is known about the risk of this therapy and its safety when it is applied to the tumour, or the impact on the factor of QoL. The review aimed to address the benefits and limitations of PBMT in premalignant oral lesions, as well as the conflicting evidence concerning the relationship between tumour cell proliferation and the applied dose of photonic energy (fluence) in treating oral mucositis induced by head and neck cancer (H&N) treatments. The objective was to appraise the current concept of PBMT safety in the long-term, along with its latent impact on tumour reaction. This review highlighted the gap in the literature and broaden the knowledge of the current clinical evidence-based practice, and effectiveness, of PBMT in H&N oncology patients. As a result, the authors concluded that PBMT is a promising treatment modality. However, due to the heterogeneity of our data, it needs to undergo further testing in well-designed, long-term and randomised controlled trial studies, to evaluate it with diligent and impartial outcomes, and ensure laser irradiation’s safety at the tumour site.

Simultaneous photoablative and photodynamic 810-nm diode laser therapy as an adjunct to non-surgical periodontal treatment: an in-vitro study

BACKGROUND

The use of lasers at different wavelengths has been proposed in combination with conventional non-surgical periodontal treatment in order to improve the clinical outcome of periodontal disease. However, the clinical use of laser photonic energy is still the subject of research and debate because the antibacterial activity of the laser is dependent upon method, laser parameters, quantity of bacteria, species selected and photosensitizers used.

METHODS

We evaluated the in-vitro bactericidal activity of 810 nm diode-laser irradiation in simultaneous photoablative and photodynamic mode against the major pathogenic bacterial organisms associated with periodontal inflammation and disease. We used indocyanine green as photosensitizer and the high-energy density of 161.7 J/cm2 or 215.0 J/cm2 for the photoablative-photodynamic irradiation.

RESULTS

The bacteria were drastically affected by the 215.0 J/cm2 irradiation in the presence of indocyanine green. In fact, the number of Porphyromonas gingivalis and Prevotella intermedia was reduced by 99.9% (P<0.001), while the number of Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Actinomyces viscosus decremented by 83.3% (P<0.01), 86.8% (P<0.05), 75% (P<0.01) and 78.7% (P<0.001), respectively. P. gingivalis and P. intermedia were the only bacteria that were sensitive to the treatment with indocyanine green dye and 161.7 J/cm2 of laser irradiation (P<0.001).

CONCLUSIONS

Our preliminary in-vitro data suggest that simultaneous photoablative-photodynamic irradiation could be a promising therapy against a wide range of bacteria involved in periodontal disease. We believe that further additional in-vivo investigation is necessary, to enable a more complete picture of effectiveness within a clinical setting to be established. In addition, the use of a simultaneous photoablative-photodynamic therapy is suggested to reduce treatment time, without compromising the efficacy against the periodontal pathogens.

Postoperative Quality of Life Following Conventional Endodontic Intracanal Irrigation Compared with Laser-Activated Irrigation: A Randomized Clinical Study

Objective: The aim of this randomized clinical study was to evaluate the effect of laser-activated irrigation using a photon-induced photoacoustic streaming (PIPS) technique on postoperative pain following completion of root canal obturation. Methods: Fifty-six patients were enrolled in this randomized clinical trial. Fifty-six healthy premolars or molars with asymptomatic irreversible pulpitis, symptomatic irreversible pulpitis, or symptomatic pulpal necrosis, with or without apical periodontitis, were mechanically prepared for endodontic treatment and divided into two groups. Patients were randomly allocated to treatment groups. In the positive control group G1, the final irrigation with 2 cc of 5.25% sodium hypochlorite (NaOCl) was achieved using a 27G needle, introduced into the canal to a distance of 5 mm from the predetermined working length. In the experimental group G2, the root canals were irrigated with 17% ethyldiamine tetric acid (EDTA) and 5.25% NaOCl following the PIPS protocol, using an Er:YAG 2940 nm laser (LightWalker ATS^®; Fotona, Slovenia) with a 600 μm diameter tip and operating parameters of 20 mJ per pulse, 15 Hz frequency, 0.3 W average power, and a 50-μs pulse duration. Postoperatively, the patients were advised to take a minor analgesic (ibuprofen 400 mg) in the event of pain perception. Postoperative pain levels were assessed after 24, 48, and 72 h and 7 days through the use of a Visual Analogue Scale questionnaire, completed by each patient. Data were analyzed using Kolmogorov-Smirnov, Fisher Exact, Chi square, Mann-Whitney test, and Friedman's test. The level of significance was set at α = 0.05. Results: There was no significant difference between the laser-irradiated group and the control group (p < 0.5). Laser activation of irrigating solutions did not increase postoperative pain. Conclusions: The outcome of this investigation indicated that PIPS was as effective as conventional irrigation in relation to postoperative pain, making this activation technique interesting to use for supplementary root canal disinfection.

Nonsurgical Periodontal Treatment by Erbium:YAG Laser Promotes Regression of Gingival Overgrowth in Patient Taking Cyclosporine A: A Case Report

Objective and background: To report on a case of cyclosporine A-related gingival overgrowth (GO) treated by conventional scaling and Erbium:YAG laser that unexpectedly showed complete healing with normalization of the gingiva, making unnecessary further surgical treatment for gingival volume reduction. Since Erbium:YAG laser was approved in 1997 by the U.S. Food and Drug Administration for hard and soft tissue treatments in dentistry, several studies have been published to demonstrate its efficacy for bone cutting, plaque and subgingival calculus removal, and antiseptic effects both on soft and hard periodontal tissues. Methods: We report herewith the case of a patient undergoing cyclosporine A therapy, affected by GO who underwent scaling and full mouth disinfection with chlorhexidine 2% rinses, followed by Erbium:YAG laser treatment of gingival pseudopockets, without surgical removal of the overgrown gingiva. Results: Unexpectedly, complete healing of the periodontal tissues was observable after one single laser application and no adjunctive surgical procedure was necessary. Conclusions: Erbium:YAG laser could be considered a really effective option for the nonsurgical treatment of drug-induced GO, avoiding the surgical procedures and also promoting a fast healing and a patient compliance surely higher than conventional techniques.

Evaluation of the outcome of various laser therapy applications in root canal disinfection: A systematic review

BACKGROUND

Any successful endodontic therapy requires elimination of the endodontic biofilms through meticulous root canal disinfection methods. Sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) are the most common effective irrigants, in removing smear-layer from the coronal and middle thirds of the dental canals but reduced considerably towards the apical one third. In recent years, newly alternative treatment modalities have been proposed, including high-power lasers and antimicrobial photodynamic therapy (aPDT). Our work was conducted to evalaute the outcome of root canal disinfection in relation to the efficacy of various treatment modalities. Furthermore, every effort was made to present an overview of the aPDT outcomes, as a model for this application, and to propose laser parameters protocol with positive results.

METHODS

The electronic databases PubMed was searched from January 2013- January 2019. Our inclusive criteria based on laser therapy applications, as a model for root canal disinfection. The search terms utilised various combinations as follows: photodynamic therapy or antimicrobial photodynamic therapy or photoactivated disinfection or light activated disinfection or laser activated disinfection or laser therapy, and endodontic.

RESULTS

The results of this systematic review concluded that the effectiveness of aPDT and various laser wavelengths protocols, in removing endodontic biofilms from infected root canals, remains unattainable.

CONCLUSIONS

Study concluded that the combination of aPDT with antimicrobial irrigants could provide a synergetic effect. However, due to the heterogeneity of the selected studies and their limitations, in terms of lack of standardised protocol or discrepancy in the methodology, authors suggest further validated approaches to achieve optimal outcomes.

GuttaCore Pink, Thermafil and Warm Vertically compacted gutta-percha retreatment: Time required and quantitative evaluation by using ProTaper files

The goal of non-surgical treatment is to obtain an access to the root canal system in order to remove the previous filling. We analized 45 human single-canal roots, mesial roots of mandibular molars and distal roots of maxillary molars without previous endodontic treatment, fractures, resorptive defects or open apices. We evaluated the time required to retreat root canals obturated by a new generation of GuttaCore, GuttaCore Pink^®, compared to Thermafil^® and Warm Vertically compacted gutta-percha, by using ProTaper^® Retreatment and ProTaper^® Universal. Moreover, a quantitative analysis of residual filling material in the canal after retreating and shaping was performed. The Kruskal-Wallis and Dunn's test were used to determine significant differences. Our data show that the GuttaCore Pink^® can be removed from the root canal system in a lower amount of time compared to the Thermafil^®. Concerning the amount of residual filling material, there are no significant differences between the three groups.

The 808 nm and 980 nm infrared laser irradiation affects spore germination and stored calcium homeostasis: A comparative study using delivery hand-pieces with standard (Gaussian) or flat-top profile

Photobiomodulation relies on the transfer of energy from incident photons to a cell photoacceptor. For many years the concept of photobiomodulation and its outcome has been based upon a belief that the sole receptor within the cell was the mitochondrion. Recently, it has become apparent that there are other photoacceptors operating in different regions of the electromagnetic spectrum. Alternative photoacceptors would appear to be water and mechanisms regulating calcium homeostasis, despite a direct effect of laser photonic energy on intracellular calcium concentration outwith mitochondrial activity or influence, have not been clearly demonstrated. Therefore, to increase the knowledge of intracellular‑calcium and laser photon interaction, as well as to demonstrate differences in irradiation profiles with modern hand-pieces, we tested and compared the photobiomodulatory effect of 808 nm and 980 nm diode laser light by low- and higher-energy (60s, 100 mW/cm², 100 mW/cm², 500 mW/cm², 1000 mW/cm², 1500 mW/cm², 2000 mW/cm²) irradiated with a "standard" (Gaussian fluence distribution) hand-piece or with a "flat-top" (uniform fluence) hand-piece. For this purpose, we used the eukaryote unicellular-model Dictyostelium discoideum. The 808 nm and 980 nm infrared laser light, at the energy tested directly affect the stored Ca²⁺ homeostasis, independent of the mitochondrial respiratory chain activities. From an organism perspective, the effect on Ca²⁺-dependent signal transduction as the regulator of spore germination in Dictyostelium, demonstrates how a cell can respond quickly to the correct laser photonic stimulus through a different cellular pathway than the known light-chromophore(mitochondria) interaction. Additionally, both hand-piece designs tested were able to photobiomodulate the D. discoideum cell; however, the hand-piece with a flat-top profile, through uniform fluence levels allows more effective and reproducible effects.