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Objective The present study aimed to evaluate the histological outcome of tunnel β-TCP blocks grafting in extraction sockets missing the buccal bone wall, after 6 months of healing. Background Tunnel β-tricalcium phosphate (β-TCP) blocks made of randomly organized tunnel-shaped β-TCP ceramics appeared promising for alveolar ridge preservation in tooth extraction sockets missing the buccal bone, in a previous study in dogs, with a 2-month healing time. Methods In six beagle dogs, the maxillary first premolars were extracted and the buccal bone was surgically removed to create bone defects of 4 mm (mesio-distal) × 5 mm (apico-coronal) × 4 mm (bucco-palatal). Thus, extraction sockets missing the buccal bone plate were grated with tunnel β-TCP blocks (test) or left empty for spontaneous healing (control). Histology/histomorphometry was performed after 6 months of healing. Results The horizontal bucco-palatal width of the alveolar ridge was significantly greater at test sites than at control sites. The amount of mineralized tissue was greater at test sites (57.8% ± 11.1%) than at control sites (28.9% ± 8.5%), while the amount of connective tissue was significantly greater at control sites (41.7% ± 6.4%) than at test sites (19.6% ± 9.2%). No significant difference was found between sites in terms of basic multicellular units and bone marrow. Residual β-TCP at test sites was 5.8% ± 3.2%. Conclusion Grafting with tunnel β-TCP block significantly limited the resorption of the alveolar ridge at extraction sockets missing the buccal bone compared with sites left to heal spontaneously, even after 6-month follow-up.

Background The alveolar ridge undergoes pronounced reduction in height and width following tooth extraction. This study aims to comparatively evaluate the potential for ridge preservation in extraction sockets with buccal bone deficiency of β-tricalcium phosphate coated with poly lactide-co-glycolide (β-TCP/PLGA) and conventional particulate β-TCP. Methods In six beagles, maxillary first premolars were extracted after removal of their buccal bone plates. Standardized bone defects (4 [mesiodistal width] × 4 [buccopalatal width] × 5 [depth] mm) were created at the sites of extraction sockets and filled with β-TCP/PLGA (test sites) or particulate β-TCP (control sites). Microcomputed tomography, histologic, and histometric evaluations were performed 12 weeks post-surgery. Results The test sites exhibited a significantly greater bone volume than the control sites (25.7 ± 2.14 versus 16.0 ± 3.3 mm3 ), although no statistically significant difference was detected in bone material density (746.3 ± 23.9 versus 714.5 ± 37.0 g/cm3 , respectively). Relative to the control sites, the test sites exhibited significantly greater alveolar-ridge coronal (2.0 ± 0.4 versus 1.1 ± 0.3 mm) and middle (2.9 ± 0.2 versus 2.1 ± 0.3 mm) horizontal widths and proportions of woven bone (50.3 ± 8.1% versus 38.0 ± 5.2%) and bone marrow (17.7 ± 6.6% versus 9.7 ± 4.1%) but a significantly lower proportion of connective tissue (10.7 ± 4.5% versus 18.3 ± 5.7%). Conclusion Within the limitations of this study, the moldable β-TCP/PLGA graft appears to exhibit a greater potential than the conventional particulate β-TCP graft for ridge preservation of extraction sockets with buccal bone deficiency.

OBJECTIVES This study aimed to evaluate the plaque removal efficacy of a newly developed electric-powered ionic toothbrush vs. a manual toothbrush. MATERIALS AND METHODS Manual or electric-powered ionic toothbrushes were randomly assigned to 30 healthy volunteers divided into two groups (Phase I). After 2 min of brushing, all tooth surfaces were stained with a plaque staining solution, and blinded examiners performed scoring using the Rustogi Modification of the Navy Plaque Index. Plaque removal rate was calculated at the central incisors, first premolar and first molar, as representative teeth, in the maxilla and mandibula. One week following Phase I, the same examinations were repeated in all subjects using another toothbrush (Phase II), as a crossover design. RESULTS Electric ionic toothbrushes demonstrated a significantly higher plaque removal rate than manual toothbrushes in the premolar and molar areas (p

BACKGROUND AND OBJECTIVE Full-mouth scaling and root planing (FM-SRP) acts as a potent inflammatory stimulus immediately after treatment; however, systemic inflammation typically improves in the long term. The contribution of FM-SRP to systemic biological and acute-phase responses is largely unknown. The purpose of this prospective intervention study was to assess the systemic and local biological responses after FM-SRP. MATERIAL AND METHODS Thirty-one patients with generalized moderate-to-severe chronic periodontitis received 1-stage FM-SRP. Measurement of clinical parameters and body temperature as well as collection of subgingival plaque, peripheral blood and gingival crevicular fluid was performed before and after treatment 2 or 3 times. Quantification of periodontopathic bacteria in the sulcus and measurement of corresponding serum IgG titers were performed. Systemic and local inflammatory markers such as endotoxin, high-sensitive C-reactive protein (hs-CRP) and 6 inflammatory cytokines were assessed using high-sensitivity assays. RESULTS Compared to baseline values, FM-SRP resulted in a substantial improvement in clinical parameters (P

This study evaluated the effectiveness of swept-source optical coherence tomography (ss-OCT) for detecting calculus and root cementum during periodontal therapy. Optical coherence tomography (OCT) images were taken before and after removal of subgingival calculus from extracted teeth and compared with non-decalcified histological sections. Porcine gingival sheets of various thicknesses were applied to the root surfaces of extracted teeth with calculus and OCT images were taken. OCT images were also taken before and after scaling and root planing (SRP) in human patients. In vitro, calculus was clearly detected as a white-gray amorphous structure on the root surface, which disappeared after removal. Cementum was identified as a thin, dark-gray layer. The calculus could not be clearly observed when soft tissues were present on the root surface. Clinically, supragingival calculus and cementum could be detected clearly with OCT, and subgingival calculus in the buccal cervical area of the anterior and premolar teeth was identified, which disappeared after SRP. Digital processing of the original OCT images was useful for clarifying the calculus. In conclusion, ss-OCT showed potential as a periodontal diagnostic tool for detecting cementum and subgingival calculus, although the practical applications of subgingival imaging remain limited.

Background and Objective Tissue engineering by using recombinant human (rh) growth factor technology may offer a promising therapeutic approach for treatment of gingival recession. Fibroblast growth factor-2 (FGF-2) has shown the ability to promote periodontal regeneration. Gelatin/beta-tricalcium phosphate (gelatin/β-TCP) sponges have been developed to control the release of growth factors. The present study evaluated the periodontal regenerative efficacy of rhFGF-2 by comparing gelatin/β-TCP sponges incorporated with rhFGF-2 to the scaffolds alone in artificially created recession-type defects in dogs. Material and methods Critically sized buccal gingival recession defects were surgically created on maxillary canine teeth of five dogs. In each animal, defects were randomized to receive either a gelatin/β-TCP sponge soaked with rhFGF-2 (gelatin/β-TCP/rhFGF-2) or phosphate-buffered saline (gelatin/β-TCP). Eight weeks after surgery, biopsy specimens were obtained and subjected to microcomputed tomography and histological analyses. Results Complete root coverage was achieved in both groups. Microcomputed tomography revealed significantly greater new bone volume in the gelatin/β-TCP/rhFGF-2 group. Histologically, both groups achieved periodontal regeneration; however, gelatin/β-TCP/rhFGF-2 sites exhibited more tissue regeneration, characterized by significantly larger amounts of new cementum and new bone. Gelatin/β-TCP sites featured increased long junctional epithelium and connective tissue attachment. In the gelatin/β-TCP/rhFGF-2 sites, new bone exhibited many haversian canals and circumferential lamellae as well as remarkably thick periosteum with blood vascularization and hypercellularity. Conclusion Within the limitations of this study, rhFGF-2 in gelatin/β-TCP sponges exhibits an increased potential to support periodontal wound healing/regeneration in canine recession-type defects.

Background and objective Full-mouth scaling and root planing (FM-SRP) increases the systemic levels of inflammatory mediators via early inflammation but may be inhibited using an antimicrobial agent. This prospective intervention study evaluates the biological response and clinical effects of FM-SRP with and without systemically administered azithromycin (AZM). Materials and methods A multicenter parallel randomized controlled and open-label trial. A central randomization center used computer-generated tables to allocate treatments. Sixty-three patients with moderate to severe generalized periodontitis (New American Academy of Periodontology Classification: Stage3 or 4, Grade B) were randomly assigned to receive FM-SRP with AZM (test group, n = 32) or FM-SRP without AZM (control group, n = 31). Clinical parameters and body temperature were measured, and subgingival plaque, peripheral blood, and gingival crevicular fluid were collected before and after treatment. Periodontopathic bacteria and IgG titers were measured by gingival crevicular fluid and peripheral blood. High-sensitivity assays were used to analyze systemic and local inflammatory markers, such as endotoxin, high-sensitive CRP (hs-CRP), and six inflammatory cytokines. Follow-up 6 weeks. Results The total number of bacteria and the number of Porphyromonas gingivalis and Prevotella intermedia were significantly lower in the test group after FM-SRP. IgG titers for P gingivalis significantly decreased after FM-SRP with AZM, and the body temperature increased significantly after FM-SRP without AZM. In the control group, serum hs-CRP, IFN-γ, IL-12p70, and IL-6 were significantly increased one day after treatment, but subsequently decreased below the original numerical value. In the test group, only hs-CRP showed a significant increase. Conclusions FM-SRP resulted in similar improvements in clinical parameters with and without the use of AZM. Inflammatory mediators showed no difference between the two groups after FM-SRP treatment. The use of AZM was effective in preventing the elevation of body temperature after FM-SRP.

OBJECTIVES To evaluate the effect of enamel matrix derivative in liquid form (EMD-liquid) as adjunct to grafting with natural bovine bone (NBB), on new bone formation and osseointegration in buccal dehiscence defects at dental implants. MATERIAL AND METHODS In six beagles, 3 months after extraction of the mandibular premolars and first molars. Three titanium implants (3.3 O × 8.0 mm) were inserted, and dehiscence-type defects (mesiodistal width 3 mm × 5 mm depth) were created on their buccal aspect. The defects were randomly assigned to one of the following three treatment groups: Group 1: NBB, Group 2: NBB/EMD-L, Group 3: Control. All sites were covered with a collagen membrane. Histomorphometric measurements were performed after 3 months of healing. RESULTS New bone area, bone-to-implant contact (BIC), and first BIC (fBIC) in the NBB and NBB/EMD-L groups were significantly greater than in the control group (p

Reduction in alveolar ridge volume is a direct consequence of tooth extraction. Tunnel β-tricalcium phosphate (β-TCP) blocks were manufactured from randomly organized tunnel-shaped β-TCP ceramic. Efficacy of these blocks compared to extraction alone for alveolar ridge preservation after tooth extraction with buccal bone deficiency was evaluated.Maxillary first premolars of six beagle dogs were extracted after removing the buccal bone, and bone defects of 4 × 4 × 5 mm (mesio-distal width × bucco-palatal width × depth) were created. Fresh extraction sockets with buccal bone defects were filled with tunnel β-TCP blocks at test sites. Two months after the operation, histologic and histometric evaluations were performed.Regarding histologic sections, coronal and middle horizontal widths of the alveolar ridge were significantly greater at test sites (3.2 ± 0.5 and 3.6 ± 0.4 mm, respectively) than at control sites (1.2 ± 0.3 and 2.0 ± 0.6 mm, respectively). The amount of woven bone was significantly greater at test sites (62.4% ± 7.9%) than at control sites (26.8% ± 5.3%), although that of connective tissue and bone marrow was significantly greater at control sites (38.1% ± 6.2% and 16.0% ± 6.9%, respectively) than at test sites (10.7% ± 5.7% and 4.1% ± 2.2%, respectively). Regarding basic multicellular units, no statistically significant difference was found between the test and control sites (0.5% ± 0.1% and 0.6% ± 0.1%, respectively).Tunnel β-TCP blocks represent an effective bone-graft material for alveolar ridge preservation in fresh extraction sockets with buccal bone defects.

The histological outcomes after nonsurgical periodontal treatment with enamel matrix derivatives (EMD) remain controversial. The present study evaluated periodontal wound healing after scaling and root planing (SRP) with subgingival application of EMD for treatment of experimental periodontitis. Periodontal breakdown was induced by applying silk ligatures around mandibular third and fourth premolars of six beagle dogs until radiographic bone loss progressed to approximately half of the root length. Probing pocket depth (PPD) and clinical attachment level (CAL) were proximally measured 2 weeks after ligature removal (baseline). Mesial and distal surfaces of the experimental teeth were subjected to SRP and randomized using a split-mouth design to subgingival application of EMD (test) or normal saline (control). PPD and CAL were re-evaluated at 11 weeks. Animals were sacrificed at 12 weeks for histological analyses. No significant differences were observed in PPD and CAL between both groups at baseline and at 11 weeks. Histologically, test sites exhibited a greater amount of new cementum than that did the control sites (p

Background and Objective Tissue regeneration is affected by the porosity, chemical properties and geometric structure of graft materials. Regeneration of severe periodontal defects, such as one-wall intrabony defects, is difficult because of reduced tissue support, and bone grafts are commonly used in such cases. In the present study, a tunnel-structured β-tricalcium phosphate (tunnel β-TCP) graft material designed to stimulate bone formation was fabricated. The objective of this pilot study was to evaluate the effect of this graft material on periodontal regeneration in one-wall intrabony defects in dogs. Material and Methods Six male beagle dogs were used in this study. First, the mandibular second and third incisors were extracted. Experimental surgery was performed 12 wk after tooth extraction. Bilateral 4 × 8 mm (width × depth) one-wall intrabony defects were created in the mesial side of the mandibular canines. At the experimental sites, the defects were filled with tunnel β-TCP, whereas the control defects were left empty. Twelve weeks after surgery, qualitative and quantitative histological analyses were performed. Results There were no signs of clinical inflammation 12 wk after surgery. Coronal extension indicative of new bone formation was higher at the experimental sites than at the control sites, although the differences between both the sites in the newly formed cementum and connective tissue attachment were not significant. Newly formed periodontal ligament and cementum-like tissue were evident along the root surface at the experimental sites. The inner surface of the tunnels was partially resorbed and replaced with new bone. New blood vessels were observed inside the lumens of tunnel β-TCP. Conclusion Tunnel β-TCP serves as a scaffold for new bone formation in one-wall intrabony defects.

Periodontitis is an inflammatory disease that leads to the loss of tooth-supporting tissues. Conventional periodontal treatment is generally unable to promote regeneration of the damaged periodontal structures. Recently, several studies have investigated the use of tissue engineering to facilitate predictable periodontal regeneration. This article reviews various technologies related to periodontal tissue engineering. These include bone grafting, guided tissue regeneration, enamel matrix protein derivative, growth factors, stem cell therapy, cell sheet engineering and laser treatment. Studies carried out by this group, and available clinical data, together with the authors own clinical experiences, are discussed. In addition, possible new directions that need to be exploited to make periodontal tissue engineering a clinical success are discussed herein.

Alveolar ridge augmentation is an important procedure to restore tooth loss. Several types of graft materials have been used for augmenting the alveolar ridge. An injectable calcium phosphate cement (CPC) has been applied to periodontal bone defects and has shown favourable results. Thus, this CPC may work as an effective graft material for alveolar ridge augmentation. The aim of this study was to evaluate the effectiveness of the CPC for large-scaled (about 7 x 8 x 6 mm) ridge augmentation in dogs. Alveolar ridge defects were created bilaterally in the maxilla of six beagle dogs. The CPC was applied to one of the bilateral maxillary defects. The untreated defect on the contralateral side served as control. The animals were sacrificed at 6 months after surgery and decalcified histological specimens of the alveolar ridge were prepared histometrically and evaluated under a light microscope. Newly formed and reconstructed alveolar ridges covering the CPC were observed in all experimental sites. In the control sites, only slight newly bone formation was observed. Histomorphometrical analysis indicated that the CPC grafted group exhibited significantly (P = 0.0001) increased area and height in new bone formation compared with those of the control group. The results indicate that the CPC appears to be an effective material for alveolar ridge augmentation and may act as a space maintainer to conduct new bone formation.

Recombinant human bone morphogenetic protein-2 has been shown to promote bone formation because of its osteoinductive property. The purpose of this study was to evaluate the efficacy of rhBMP-2 delivered on a poly (D, L-lactic-co-glycolic acid) copolymer/gelatin sponge (PGS) in vertical alveolar ridge augmentation on height-reduced edentulous mandible to verify the retention of rhBMP-2 withstanding the pressure of soft tissues. Coronal defects of the alveolar bone were created in six adult beagle dogs. After a healing period of 9 weeks, PGSs with or without rhBMP-2 (0 or 0.4 mg mL(-1)) were implanted on the defects(6 mm in height, 30 mm in length, 8 mm in width). Sixteen weeks after implantation, the bone mineral content (BMC) and the total bone area were measured by peripheral quantitative computed tomography. The BMC and the total bone area of the defect sites with rhBMP-2 group were significantly greater (133+/-33 mg mm(-1), 277+/-54 mm2, respectively) than those of the control group (80+/-19 mg mm(-1), 155+/-49 mm2, respectively) (P

Objective: The ultimate goal of periodontal treatment is to regenerate the damaged periodontal support. Although periodontal ligament (PDL) cells are essential for periodontal regeneration, few studies have reported the transplantation of periodontal ligament cells to periodontal defects. We developed a new method to apply periodontal ligament cells as a sheet to the defect. The aim of this study was to investigate the periodontal healing after application of the periodontal ligament cell sheet in beagle dogs. Methods: Autologous periodontal ligament cells were obtained from extracted premolars of each beagle dog. Periodontal ligament cell sheets were fabricated using a temperature-responsive cell culture dish. Dehiscence defects were surgically created on the buccal surface of the mesial roots of bilateral mandibular first molars of each dog. In the experimental group (five defects), periodontal ligament cell sheet with reinforced hyaluronic acid carrier was applied to the defect. Only the hyaluronic acid carrier was applied to the contralateral side as a control (five defects). Eight weeks after surgery, the animals were sacrificed and decalcified specimens were prepared. Healing of the periodontal defects was evaluated histologically and histometrically. Results: No clinical signs of inflammation or recession of gingiva were observed in both experimental and control groups. In the experimental group, periodontal tissue healing with bone, periodontal ligament and cementum formation was observed in three out of five defects. In the control group, such periodontal tissue formation was not observed except in one defect. Histometric analysis revealed that the formation of new cementum in the experimental group was significantly higher than that in the control group. Conclusion: The periodontal ligament cell sheet has a potential to regenerate periodontal tissue and may become a novel regenerative therapy.