Learning from clinical phenotypes: Low-dose biophotonics therapies in oral diseases.

This narrative review on the use of biophotonics therapies for management of oral diseases is written as a tribute to Prof. Crispian Scully. His seminal contributions to the field are highlighted by the detailed, comprehensive description of clinical presentations of oral diseases. This has enabled a more thorough, fundamental understanding of many of these pathologies by research from his group as well as inspired mechanistic investigations in many groups globally. In the same vein, a major emphasis of this narrative review is to focus on the evidence from human case reports rather than in vitro or in vivo animal studies that showcases the growing and broad impact of biophotonics therapies. The similarities and differences between two distinct forms of low-dose biophotonics treatments namely photodynamic therapy and photobiomodulation therapy are discussed. As evident in this review, a majority of these reports provide promising evidence for their clinical efficacy. However, a lack of adequate technical details, precise biological rationale, and limited outcome measures limits the current utility of these treatments. Future investigations should attempt to address these shortcomings and develop better designed, rigorous, controlled studies to fully harness the tremendous potential of low-dose biophotonics therapies.

Laser-activated transforming growth factor-ß1 induces human ß-defensin 2: implications for laser therapies for periodontitis and peri-implantitis.

BACKGROUND: There is increasing popularity of high-power lasers for surgical debridement and antimicrobial therapy in the management of peri-implantitis and periodontal therapy. Removal of the noxious foci would naturally promote tissue healing directly. However, there are also anecdotal reports of better healing around routine high-power laser procedures. The precise mechanisms mediating these effects remain to be fully elucidated. This work examines these low-dose laser bystander effects on oral human epithelial and fibroblasts, particularly focusing on the role of human ß-defensin 2 (HBD-2 or DEFB4A), a potent factor capable of antimicrobial effects and promoting wound healing. MATERIAL AND METHODS: Laser treatments were performed using a near-infrared laser (810 nm diode) at low doses. Normal human oral keratinocytes and fibroblast cells were used and HBD-2 mRNA and protein expression was assessed with real time polymerase chain reaction, western blotting and immunostaining. Role of transforming growth factor (TGF)-ß1 signaling in this process was dissected using pathway-specific small molecule inhibitors. RESULTS: We observed laser treatments robustly induced HBD-2 expression in an oral fibroblast cell line compared to a keratinocyte cell line. Low-dose laser treatments results in activation of the TGF-ß1 pathway that mediated HBD-2 expression. The two arms of TGF-ß1 signaling, Smad and non-Smad are involved in laser-mediated HBD-2 expression. CONCLUSIONS: Laser-activated TGF-ß1 signaling and induced expression of HBD-2, both of which are individually capable of promoting healing in tissues adjacent to high-power surgical laser applications. Moreover, the use of low-dose laser therapy itself can provide additional therapeutic benefits for effective clinical management of periodontal or peri-implant disease.

Micro-Computed tomography (CT) based assessment of dental regenerative therapy in the canine mandible model.

High-resolution 3D bone-tissue structure measurements may provide information critical to the understanding of the bone regeneration processes and to the bone strength assessment. Tissue engineering studies rely on such nondestructive measurements to monitor bone graft regeneration area. In this study, we measured bone yield, fractal dimension and trabecular thickness through micro-CT slices for different grafts and controls. Eight canines underwent surgery to remove a bone volume (defect) in the canine's jaw at a total of 44 different locations. We kept 11 defects empty for control and filled the remaining ones with three regenerative materials; NanoGen (NG), a FDA-approved material (n=11), a novel NanoCalcium Sulfate (NCS) material (n=11) and NCS alginate (NCS+alg) material (n=11). After a minimum of four and eight weeks, the canines were sacrificed and the jaw samples were extracted. We used a custom-built micro-CT system to acquire the data volume and developed software to measure the bone yield, fractal dimension and trabecular thickness. The software used a segmentation algorithm based on histograms derived from volumes of interest indicated by the operator. Using bone yield and fractal dimension as indices we are able to differentiate between the control and regenerative material (p<0.005). Regenerative material NCS showed an average 63.15% bone yield improvement over the control sample, NCS+alg showed 55.55% and NanoGen showed 37.5%. The bone regeneration process and quality of bone were dependent upon the position of defect and time period of healing. This study presents one of the first quantitative comparisons using non-destructive Micro-CT analysis for bone regenerative material in a large animal with a critical defect model. Our results indicate that Micro-CT measurement could be used to monitor in-vivo bone regeneration studies for greater regenerative process understanding.

Germicidal activity of antimicrobials and VIOlight Personal Travel Toothbrush sanitizer: an in vitro study.

OBJECTIVES: The study evaluated the antibacterial effect of VIOlight (VL) Personal Travel Toothbrush Sanitizer on biofilms after toothbrush exposure to human saliva compared to Listerine Antiseptic (LA), 3% hydrogen peroxide (3%HP) and water. METHODS: Twenty toothbrush heads (n=5/Gp) were immersed in saliva and to allow for bacterial growth and biofilm formation for 24h. VL sanitizer and antiseptic(s) were used for 7 min; after treatment, brush heads were rinsed and placed into 10 mL of 2x AOAC Letheen Broth, sonicated and vortexed for 10s. Tenfold serial dilutions were prepared and plated and incubated aerobically and anaerobically. Log(10)CFU/mL data were compared utilizing ANOVA (p<0.05). RESULTS: Results showed 3%HP with significantly lower counts than LA, VL and control for aerobic and anaerobic bacteria. LA had significantly lower counts than VL and control for both types of bacteria and VIOlight had significantly lower counts than the control for aerobic bacteria. 3%HP and LA were most effective in rapidly killing bacteria when compared to VIOlight. CONCLUSIONS: Results showed that 3% hydrogen peroxide was most effective in reducing the numbers of both aerobic and anaerobic bacteria present on the toothbrush heads. Under the same test conditions, Listerine Antiseptic was shown to be secondarily effective for the same bacteria while the VIOlight unit was the least effective when compared to the other treatment groups.

Effects of occlusal load on cervical lesions.

Toothbrush abrasion has been considered to cause cervical lesions. However, some investigators have proposed that occlusal loading factors direct tensile stresses at the cervical area, resulting in wedge-shaped abfraction defects. The purpose of this study is to investigate the role of axial and non-axial load on the development of cervical lesions. Matched paired premolars, extracted for orthodontic purposes, were used in a custom-fabricated toothbrushing apparatus. A periodontal sulcus width of 0b1 mm with 1 mm gingival recession was simulated with denture base resin. In phase 1, eight matched premolar pairs were subjected to 80 h (1b4 million strokes) of brushing and 300 g of toothbrush force. Toothpaste slurry was applied continuously through the toothbrush. One specimen in each pair was subjected to 250 h and 45 kg of continuous axial load, while the other unloaded tooth served as a negative control. In phase 2, 10 matched premolar pairs were subjected to the same conditions; however, the experimental teeth were subjected to 250 h and 45 kg of intermittent non-axial load, directed at a 45 degrees angle to the buccal cusp. Rubber impressions were made of the cervical lesions, then trimmed, weighed, and compared to determine the amount of tooth material lost. When teeth were loaded axially, there was significantly less tooth material loss (P < 0b02); however, when teeth were loaded non-axially, there was no significant difference (P =0b80) when compared with controls. Optical and scanning electron microscopy did not reveal any significant differences in the morphology between pairs. Our data suggest that the application of occlusal load may not necessarily play a significant role in the progression of cervical tooth wear commonly referred to as abfraction.

Dentinal hypersensitivity: review of aetiology, differential diagnosis, prevalence, and mechanism.

Dentinal hypersensitivity is a painful response to a non-noxious stimulus applied to exposed dentine in the oral environment. Dentine exposure results from a combination of two or more aetiological factors that lead to loss of enamel and/or loss of cementum. The hydrodynamic theory is the most accepted theory that explains the excitement of pulpal nerve fibres by a stimulus applied to the exposed dentine. Dentinal hypersensitivity had been reported to affect middle age people most often with no gender differences and has been shown to be influenced by tooth location.

Simultaneous implant placement and vertical ridge augmentation with a titanium-reinforced membrane: a case report.

The present report demonstrates a clinical approach to achieve vertical ridge augmentation around endosseous implants. Two implants were placed, leaving the threads exposed, in the atrophic mandibular right posterior quadrant of a male patient. Both implants were covered with a titanium-reinforced expanded polytetrafluoroethylene (e-PTFE) membrane. Second-stage surgery was performed 12 months after implant placement. Upon membrane removal, growth of mineralized tissue was observed around both implants, covering areas previously not covered by bone. Implants were then progressively loaded and restored. Titanium-reinforced e-PTFE membranes can be satisfactorily used for vertical augmentation of atrophic ridges.

Role of the finite element model in dental implants.

Computer-aided design and finite element methods (FEM) have interested dental researchers because of its use in the computer simulation and design of dental implants, a process greatly facilitated by the development of new computer technology and more accurate modeling technologies. FEM allows for a better understanding of stresses along the surfaces of an implant and in surrounding bone. This will aid in the optimization of implant design and placement of the implant into the bone; it will also help when designing the final prostheses to minimize stresses. The purpose of this review is to elucidate the role of FEM and the impact of this technology in clinical dentistry in the new millennium.

Treatment of peri-implantitis: longitudinal clinical and microbiological findings--a case report.

Failing implants can be successfully treated by surgical procedures that use either bone fillers or membranes combined with an antimicrobial treatment. In this report, we present a case of failing implants with the corresponding treatment and results of 8 years of follow-up.

A combined approach for treatment of developmental groove associated periodontal defect. A case report.

Developmental grooves are not rare and often appear on maxillary lateral incisors. This may represent a challenge and sometimes tooth extraction is inevitable. This case report describes a combined technique of regenerative and antimicrobial/root conditioning used to treat a maxillary lateral incisor in a 32-year-old woman. Tooth #10 presented a periodontal probing depth of 8 mm below the cingulum, associated with a developmental groove. The tooth was vital. After initial preparation, a palatal mini-flap was raised, granulation tissue was eliminated by means of ultrasonic bactericidal curettage and radicoloplasty performed. The surface was then treated for 3 minutes with tetracycline-HCl solution (100mg/ml), and the defect filled with sterile, medical grade, calcium sulfate. Clinical measurements were retaken at 6, 12, and 18 months. The results indicated a reduction of probing depth to 2 mm, reestablishment of the lamina dura, and radiographical evidence of bone growth. This combined treatment allowed the tooth to be saved, the palatal surgical approach did not alter the esthetics of the area, and its simplicity is recommended.

Bone regeneration with a calcium sulfate barrier.

OBJECTIVES: Bone defects are a challenge for the dental clinician. As widely accepted in guided tissue regeneration, physically halting soft connective tissue proliferation into bone allows for bone regeneration. This concept is the "osteopromotion principle." The aim of this study was to assess the osteopromoting effect of calcium sulfate as a barrier. STUDY DESIGN: Forty male Sprague-Dawley rats were used. Mucoperiosteal flaps were raised bilaterally at buccal and lingual aspects of the mandible to expose the angles. Next, 5 mm through-and-through bony defects were created bilaterally. On the test side, sterile medical grade prehardened calcium sulfate disks were applied both lingually and buccally to cover the defect. The control side defects were left uncovered. All flaps were sutured closed. Observation times were 3, 9, 18, and 22 weeks. RESULTS: Histologic analysis demonstrated that at 3 weeks all test sites showed partial or complete bone healing. Similar findings were reported for all observation times. The control group showed no bone growth at 3 and 9 weeks and partial bone healing at 18 and 22 weeks. CONCLUSIONS: This study indicates that calcium sulfate barriers can exclude connective tissues, allowing bone regeneration during healing.

Effects of smoking and smoking cessation on healing after mechanical periodontal therapy.

This study investigated the effect of cigarette smoking on 143 patients' clinical and microbiological responses to mechanical therapy. Treatment included four to six sessions of subgingival scaling and root planing and instruction in oral hygiene. Results indicate that current smokers have less healing and reduction in subgingival Bacteroides forsythus and Porphyromonas gingivalis after treatment compared to former and nonsmokers, suggesting that smoking impairs periodontal healing. As the healing and microbial response of former smokers is comparable to that of nonsmokers, smoking cessation may restore the normal periodontal healing response.

Periodontal tissue regeneration in beagle dogs after laser therapy.

BACKGROUND AND OBJECTIVE: Class III periodontal furcations still represent a challenge for the periodontist. Aim of this study was to test the effect of CO2 laser on the treatment of class III furcation defects. STUDY DESIGN/MATERIALS AND METHOD: Class III furcation defects 3 mm deep were surgically induced on mandibular premolars on six male Beagle dogs, for a total of 36 defects. After 6-8 weeks of plaque accumulation, the mean depth was 6.8 mm. Quadrants were randomly assigned to a) CO2 laser therapy (laser), b) Guided Tissue Regeneration (GTR) procedure using Gore-Tex Membranes, (Gore Tex, Flagstaff, Arizona, USA) and c) Scaling and Root planing (Sc/Rp). CO2 laser beam (El.En, Florence, Italy) was applied to the root surfaces in defocused pulsed mode at 2W, 1 Hz and a duty cycle of 6%, and on periodontal soft tissues at 13W, 40 Hz, and a duty cycle of 40%. Control quadrants received either GTR procedure or Sc/Rp. Mechanical oral hygiene was provided. At 6 months the animals were sacrificed. RESULTS: The laser group showed new attachment formation averaging 1.9 mm (sd +/- 0.5), whereas GTR and Sc/Rp showed 0.2 mm (sd +/- 0.4) and 0.2 mm (sd +/- 0.5) respectively, being the differences statistically significant between the laser group and both GTR and Sc/Rp groups (p < 0.005). CONCLUSION: CO2 laser treatment of class III furcation induced formation of new periodontal ligament, cementum and bone.

Osseointegration of rough acid-etched implants: one-year follow-up of placement of 100 minimatic implants.

Between January 1992 and October 1992, 100 Minimatic screw implants made of titanium alloy with rough acid-etched surfaces were placed in 63 consecutive partially edentulous patients. At second-stage (uncovering) surgery performed after a 4- to 6-month healing period, none of the implants showed any signs of mobility, peri-implant infection, or bone loss. After an additional healing phase averaging 2 weeks, the patients were restored with fixed prostheses. Patients were reexamined every 3 months for 1 year, with all 63 patients available for evaluation during this period. Periapical radiographs were taken preoperatively, immediately after surgery, and at 6 and 12 months after implantation. There were no signs of peri-implant radiolucencies in any of the implants, and alveolar bone loss was less than 1 mm on average 1 year after implantation. Based on Plaque Index, sulcular bleeding index, pocket probing depth, attachment level, width of keratinized mucosa, and hand-tested mobility, 99 implants were considered successful and 1 (which developed peri-implant infection) was considered a failure. Study results substantiate other reports that implants with a rough surface can yield predictable good results.

Thomas Berdmore, dentist of His Majesty, George III, and dental calculus.

Thomas Berdmore's book, Disorders of Deformities of the Teeth and Gums, presents examples of early concepts of preventive dentistry and treatment of periodontal diseases. Various aspects of dental calculus formation and composition are analyzed. Also the effects of periodontal disease as seen by Berdmore are discussed, and ways of treatment in 1770 summarized.

Topographic distribution of subgingival plaque along root surfaces of human periodontally diseased teeth. A descriptive study.

The purpose of this study was to characterize the topographical distribution and organization of subgingival plaque in periodontally diseased teeth. 26 extracted teeth were fixed and processed for undecalcified histological evaluation. The sections were cut perpendicular to the long axis of the tooth and analyzed by phase-contrast microscopy. The coronal portion of the analyzed roots showed a dense accumulation of filamentous forms, fusiform rods, coccoid forms and loosely aggregated spirochetes. The middle and apical portions showed a non-uniform distribution of the microflora, with microorganisms representing all the known morphotypes. Furthermore, plaque was detected below undisturbed periodontal fibers, indicating that plaque not only forms apically, but also in a lateral direction, penetrating and colonizing below areas where periodontal fibers are inserted into the root surface.

New directions in surgical endodontics; immediate implantation into an extraction site.

Endodontic surgical procedures may reveal compromising factors that indicate a modification of the treatment (e.g. tooth extraction, root amputation, etc.). To take advantage of the osseous height and width, as well as the natural tooth angulation, immediate placement of implants after extraction is a reasonable alternative treatment. In this study, 32 titanium alloy implants were inserted immediately after extraction of teeth diagnosed during endodontic surgery as having root fractures, perforations, or endodontic-periodontal complications. After 4 to 6 months of osseointegration, only one implant failed to integrate, and the remaining implants were prosthetically restored. Sixteen months after occlusal loading, bone loss was approximately 1.5 mm for the 31 implants remaining. It seems that the immediate placement of implants following tooth extraction due to endodontic complications is a reliable procedure.

Use of dental operating microscope in endodontic surgery.

Endodontic surgery is an alternative therapeutic approach to endodontic treatment. The outcome of the technique is affected by several factors, some of which can be eliminated by the use of a dental operating microscope. The microscope was used during the performance of 50 apicoectomies, with or without retrograde fillings. For clinical evaluation cases treated with the dental operating microscope were compared to cases treated without it. The postoperative evaluation showed a reduced incidence of symptoms in the cases treated with the dental operating microscope. More important, the dental operating microscope enhanced and facilitated each phase of endodontic surgery. Its use is highly recommended.