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Background Enamel matrix derivative (EMD) is widely used for regeneration therapy in dental clinical situations, but the mechanism of EMD bioactivity remains obscure. To clarify this mechanism, we focused on the formation of connective tissue and blood vessels. The aim of this study was to confirm whether EMD induces the formation of connective tissue and blood vessels by using the diffusion chamber (DC) technique. Materials and methods Individual DCs containing EMD (DC-EMD) or propylene glycol alginate (PGA) were implanted subcutaneously in rat dorsum. At 4 weeks after the implantation, histological analysis of DCs was performed using azan staining. Results DC-EMD induced the formation of much larger amounts of connective tissue containing abundant blood vessels than did DC-PGA. Conclusion The results indicated that EMD can induce the formation of both connective tissue and blood vessels. This bioactivity may contribute to the mechanism whereby EMD induces tissue regeneration.

Background/aim Enterococcus faecalis is responsible for most cases of endodontic treatment failure. Despite various conventional disinfection methods, root canals are not completely free of microorganisms. Photodynamic therapy (PDT) is a new antimicrobial strategy that involves the use of a non-toxic photosensitizer (PS) and a light source. The aim of this study was to evaluate the antimicrobial effect of PDT using diode laser and pyoktanin blue (PB) and confirm the nontoxicity of PB as a PS. Materials and methods Laser irradiation with an output power of 3 W was performed with PB as the PS to a bacterial solution containing E. faecalis. Then, the number of colony-forming units was counted. PB cytotoxicity was also assessed by the MTT assay. Results E. faecalis counts were reduced after laser irradiation, laser irradiation with PB, or the combination thereof compared to the control, non-irradiation or water. The 50% cytotoxic concentration value for adult human dermal fibroblasts incubated with PB for 1 min was 108 μg/ml. Conclusion Diode laser irradiation in combination with PB as the PS is efficacious for the elimination of E. faecalis without toxic effects to human dermal fibroblasts. This strategy might be useful for root canal irrigants.

Restoration of lost interdental papilla remains one of the most challenging goals for clinicians. When a single tooth is replaced with an implant, the papilla between the tooth and the implant can often be maintained or predictably reconstructed as long as the periodontal attachment and bone of the adjacent tooth is preserved. However, if the periodontal support is compromised on the neighboring natural tooth, the papilla will often be deficient or missing. This article presents a multidisciplinary treatment approach to regenerate the interdental papilla between an implant and a periodontally compromised tooth using surgical procedures and a customized abutment. Specifically, an abutment with modified subgingival contours is used to enhance support of the surgically reformed papilla.

Background/Aim: Enterococcus faecalis is responsible for most cases of endodontic treatment failure. Despite various conventional disinfection methods, root canals are not completely free of microorganisms. Photodynamic therapy (PDT) is a new antimicrobial strategy that involves the use of a non-toxic photosensitizer (PS) and a light source. The aim of this study was to evaluate the antimicrobial effect of PDT using diode laser and pyoktanin blue (PB) and confirm the nontoxicity of PB as a PS. Materials and Methods: Laser irradiation with an output power of 3 W was performed with PB as the PS to a bacterial solution containing E. faecalis. Then, the number of colony-forming units was counted. PB cytotoxicity was also assessed by the MTT assay. Results: E. faecalis counts were reduced after laser irradiation, laser irradiation with PB, or the combination thereof compared to the control, non-irradiation or water. The 50% cytotoxic concentration value for adult human dermal fibroblasts incubated with PB for 1 min was 108 μg/ml. Conclusion: Diode laser irradiation in combination with PB as the PS is efficacious for the elimination of E. faecalis without toxic effects to human dermal fibroblasts. This strategy might be useful for root canal irrigants.

The surface topography of implant fixture is an important factor affecting the osseointegration. We herein demonstrated the effects of surface microtopography of titanium disks on proliferation and differentiation of osteoblast-like cells isolated from rat calvariae. Titanium disks with machine surface (MS), rough surface (R1) and rough surface combined with small cavities (R2) were used in an in vitro culture system. Rough surfaces (R1 and R2 disks) induced stronger osteoblast proliferation and differentiation (BGP and sclerostin mRNA expressions and calcium content) than the smooth surface (MS disk). Furthermore, surface microtopography of R2 disk, which was rough with small cavities, more strongly induced cell proliferation and mineralized bone matrix production than R1 disk. Our results suggest that surface microtopography influences osteoblast proliferation and differentiation. R2 disk, which is rough with small cavities, may be used in implant fixtures to increase osseointegration.

Orthodontic extrusion of nonrestorable teeth has been used for almost 20 years as an alternative to bone grafting in preparation for implant placement. Although this technique predictably creates bone and soft tissue, and improves the socket diameter and depth, most of the bone apposition occurs in the marginal alveolar and periapical areas of the extruded tooth. To create more labial bone, the standard orthodontic extrusion technique was modified to apply pressure on the hopeless tooth both coronally and palatally, which allowed bone at the site to develop apically and labially. Gingival thickness on the labial aspect was also increased, and the tissue biotype was improved. A clinical treatment is presented that illustrates the use of this technique.

Reformation of the lost interdental papilla remains one of the most challenging goals for clinicians. When a single tooth is replaced with an implant, the papilla between the tooth and the implant can often be maintained or predictably reformed as long as the adjacent tooth's periodontal attachment and bone are preserved. However, if the periodontal support is compromised on the neighboring natural tooth, the papilla will often be deficient or missing. The cases presented herein demonstrate long-term follow-up of successful reformation of periodontal/peri-implant tissue contours, including reconstruction of lost interproximal bone and papilla at periodontally compromised sites using a combined hard and soft tissue surgical approach.

This report describes a rare situation in which external cervical resorption was associated with gingival enlargement (pyogenic granuloma) in the upper left central incisor (tooth 21) in a 28-year-old man. Tissue from the lesion was examined histopathologically; periodontal, endodontic and restorative treatments were performed; and the occlusal disharmony, which had resulted in traumatic occlusion, was corrected. Three years after these treatments, the gingiva is normal and healthy and there is no sign of recurrence of the pathologic enlargement. The patient"s periodontal condition is now routinely evaluated. In the presence of gingival enlargement resulting from inflammation, traumatic occlusion can cause progressive external root resorption.

Interproximal bony defects were treated with either porous hydroxyapatite (PHA) or decalcified freeze-dried bone allograft (DFDB) implants at two different clinical centers. Twelve paired defects in 12 patients were treated at each center. Six months post-surgically the defects were measured to assess changes from the presurgical status. No statistically significant differences were found between the groups in changes in gingival fluid, bleeding index, plaque index, or tooth mobility. The porous hydroxyapatite implant produced greater reduction in pocket depth (P = 0.03) and more gain in clinical attachment level (P = 0.001) and defect fill (P = 0.001) when compared with DFDB grafted sites. This study indicates that more clinical resolution of interproximal periodontal defects in humans can be obtained with the use of PHA than with the use of DFDB.

Twenty-three human subjects with two Class II furcation involvements in lower molars were treated with initial therapy following which presurgical measurements of pocket depth, gingival recession and attachment level were made. Periodontal flaps were used to expose the furcation defects, and one defect was implanted with porous hydroxylapatite while the other served as an unimplanted control. At the time of surgery, bone defects were measured obliquely and horizontally using a specially designed device to ensure reproducible probe angulation. Six months later the presurgical measurements were repeated, and reentry surgical procedures were carried out to measure the changes in the bone defects. Areas implanted with porous hydroxylapatite showed a statistically significant reduction in pocket depth and a statistically significant improvement in attachment level and fill of bone defects when compared with control defects. There was statistically less gingival recession in the implanted areas compared with the control sites. Control sites at six months showed no significant change in pocket depth, an increased loss of attachment and worsening of the bone defects.

Solid and granular porous hydroxylapatite implants were compared in the surgical treatment of angular interproximal periodontal defects in 10 subjects. After completion of initial therapy, presurgical measurements of pocket depth, attachment level, gingival recession, gingival fluid and tooth mobility were recorded. Six months after the surgery the measurements were repeated. The use of both forms of porous hydroxylapatite resulted in reduction in pocket depth, and probeable attachment level gains as well as gingival recession and reduction of gingival fluid and tooth mobility. These changes were similar for both granular and solid forms of porous hydroxylapatite.

A new flap design for placement of implants into osseous defects has been described. The flap design can be used in anterior and posterior areas of human subjects. Photographs of representative cases are presented. Wound healing always occurred by primary intention and without evidence of immediate graft exfoliation. Interdental soft tissue craters did not develop, making it easier for patients to maintain optimal oral hygiene. This type of flap design can also be used without grafts in order to improve postoperative soft tissue contour.