Periodontitis-affected Teeth Research Articles

Bacterial Colonization of Oral Implants from Nondental Sources

Implants showing signs of peri-implantitis harbor a microbiota similar to that of periodontitis-affected teeth. This case report describes the subgingival microbiota of a 45-year-old female with advanced periodontitis before and after complete edentulation and reconstruction with dental implants. A 3-month healing period post extraction passed before implants were placed using a two-stage submerged implant protocol. At 4- to 6-month recall visits after definitive prosthetic reconstruction, some implant sites showed bleeding on probing and localized mucositis. Microbiological culture of three inflamed peri-implant sites showed an almost identical spectrum of pathogens, including Porphyromonas gingivalis, Tannerella forsythia, and other major pathogenic bacteria characteristic of aggressive periodontitis. As natural teeth were absent for 8 months, this case report suggests that periodontal pathogens can be retained for a prolonged period of time in nondental sites, from where they can later colonize and compromise the health of dental implants. The therapeutic implications of this finding are discussed.

Evaluation of Immunoassay‐Based MMP‐8 Detection in Gingival Crevicular Fluid on a Point‐of‐Care Platform

A novel immunology-based point-of-care test has been designed to assess the activated form of matrix metalloproteinase-8 (aMMP-8) for diagnosis and monitoring of periodontal diseases. The test has been automated using an analyzer, which quantitatively measures aMMP-8 in 18 min in gingival crevicular fluid (GCF). Fluid samples were collected from healthy, gingivitis-, and periodontitis-affected teeth. The test results from the analyzer were compared with quantitative aMMP-8 immunofluorometric assay (IFMA) and in-house enzyme-linked immunosorbent assay (ELISA) as well as with the periodontal state. Preliminary results of analyzer measurements of these 34 clinical samples showed a good agreement with the results from IFMA and in-house ELISA and with the clinical picture.

Immunohistochemical Study of Bone Sialoprotein and Osteopontin in Healthy and Diseased Root Surfaces

Periodontal disease is marked by inflammation and damage to tooth-supporting tissues. In particular, damage occurs to factors present in cementum that are thought to have the ability to influence the regeneration of surrounding tissues. Bone sialoprotein and osteopontin are major non-collagenous proteins in mineralized connective tissues associated with precementoblast chemo-attraction, adhesion to the root surface, and cell differentiation. The purpose of this investigation was to determine whether the expression and distribution of bone sialoprotein and osteopontin on root surfaces affected by periodontitis are altered compared to healthy, non-diseased root surfaces. Thirty healthy and 30 periodontitis-affected teeth were collected. Following fixation and demineralization, specimens were embedded in paraffin, sectioned, and exposed to antibodies against bone sialoprotein and osteopontin. Stained sections were assessed using light microscopy. Bone sialoprotein was not detected in the exposed cementum (absence of overlying periodontal ligament) of diseased teeth. In most areas where the periodontal ligament was intact, bone sialoprotein was detected for healthy and diseased teeth. For teeth reactive for bone sialoprotein, the matrix of the cementum just below the periodontal ligament was moderately stained. A similar immunoreactivity pattern for osteopontin was observed. The absence of bone sialoprotein and osteopontin staining along exposed cementum surfaces may be due to structural and compositional changes in matrix components associated with periodontal disease. This may influence the ability for regeneration and new connective tissue attachment onto previously diseased root surfaces.

Location of putative stem cells in human periodontal ligament

The origin of cells in the mature periodontium, and the location of their progenitors, are still unknown. It is also unknown whether inflammation influences the number and distribution of these cells within the periodontium. Molecules such as STRO-1, CD146 and CD44 have been identified on a variety of mesenchymal stem cells. The aim of this study was to identify and localize putative stem cells in diseased and healthy human periodontal ligament using cell-surface markers for mesenchymal stem cells. Healthy and periodontitis-affected teeth were collected, fixed in 10% neutral-buffered formalin, decalcified and embedded in paraffin in preparation for immunohistochemistry. Antibodies against STRO-1, CD146 and CD44 were used to identify putative stem cells in the periodontal ligament. Putative stem cells were identified in both healthy and diseased periodontal ligament. They were mainly located in the paravascular region and small clusters of cells were also found in the extravascular region. Wider distributions of these cells were detected in sections of diseased ligament. Within the periodontal ligament of both healthy and diseased teeth, cells have been identified consistent with their identification as putative stem cells. The presence of an inflammatory reaction associated with periodontitis may enhance the number of these cells.

Effects of enamel matrix proteins on tissue formation along the roots of human teeth

Enamel matrix-derived proteins (EMD) are thought to trigger the formation of acellular extrinsic fibre cementum (AEFC), while other reports indicate that EMD may have osteogenic potential. The aim of the present study was to characterize the tissues developing on the root surface following application of EMD. Twelve human periodontitis-affected teeth, scheduled for extraction, were treated with EMD. Two to 6 weeks later, the teeth were extracted, demineralized and processed for embedding in acrylic and epoxy resins. New tissue formation was analysed by light and transmission electron microscopy. New tissue formation on the root was observed in the notch and on both scaled and unscaled root surfaces distant of the notch area in six defects. The newly formed tissues on the root were thick, collagenous, devoid of extrinsic fibres, and had an irregular surface contour. The presence of electron-dense, organic material in the collagenous matrix indicated at least partial mineralization. Embedded cells were numerous and the cells on the matrix surface were very large in size. Abundant rough endoplasmic reticulum and a prominent Golgi complex were evident. The presence of a split between the treated root surfaces and the newly formed tissue was a common observation, as was the presence of bacteria and host cells in the interfacial gap. Following treatment with EMD, a bone-like tissue resembling cellular intrinsic fibre cementum may develop on the root surfaces, instead of AEFC. Furthermore, EMD may both induce de novo formation of a mineralized connective tissue on scaled root surfaces and stimulate matrix deposition on old native cementum. Interfacial bonding appeared to be weak after 6 weeks of healing.

Treatment Options for Periodontitis-affected Teeth: Nonsurgical, Surgical, Regenerative, Extraction?

Ziel der vorliegenden Arbeit war es, eine kritische Übersicht über die vorhandene Evidenz bezüglich der Effektivität der nichtchirurgischen, chirurgischen und regenerativen Parodontaltherapie für die Behandlung von parodontitiserkrankten Zähnen zu geben. Neueste Daten aus systematischen Reviews und aus randomisierten, kontrollierten klinischen Studien belegten, dass die nichtchirurgische Parodontaltherapie (d. h. subgingivales Scaling und Wurzelglättung) mit supragingivaler Plaquekontrolle zu einer deutlich höheren klinischen Verbesserung als die alleinige supragingivale Plaquekontrolle führte. In Taschen ≥ 6 mm resultierte die chirurgische Parodontaltherapie in einer höheren Reduktion der Sondierungstiefen und einem höheren Gewinn an klinischem Attachment als die nichtchirurgische Parodontaltherapie. Die Behandlung von intraossären Defekten (d. h. Knochentaschen) mit einer Lappenoperation und Defektauffüllung mit verschiedenen Knochenersatzmaterialien, Schmelz-Matrix-Proteinen oder auch die Applikation von GTR-Barrieren ergaben eine deutlich höhere klinische Verbesserung als die Lappenoperation alleine. Des Weiteren zeigten Daten aus humanhistologischen Studien, dass der Gebrauch von autologem Knochen, demineralisiertem gefriergetrocknetem Knochen (DFDBA), von bestimmten xenogenen Materialien, Schmelz-Matrix-Proteinen und GTR nicht nur die klinischen Ergebnisse unterstützen, sondern auch zu einer Neubildung des Zahnhalteapparats (d. h. Wurzelzement, Desmodont und Knochen) führen können. In Grad-II-Furkationsdefekten zeigte die GTR-Therapie höhere Reduktionen von Sondierungstiefen und Gewinnen an klinischem Attachment als die Lappenoperation alleine. Zurzeit kann allein aufgrund der vorhandenen Daten aus systematischen Reviews oder aus randomisierten klinischen Studien die Frage: „Wann Parodontaltherapie, wann Extraktion?” nicht eindeutig beantwortet werden.

The characteristics of periodontal disease in respect to biofilm disease

The purpose of the present study was to examine whether bacterial biofilm concerned with bacterial colonization and growth of subgingival plaque. We observed subgingival plaque of 95 severe adult periodontitis-affected teeth by scanning electron microscope. In the coronal one-third zone of subgingival plaque, cocci, rods and others established biofilm by glycocalyx-like structure. In the middle one-third zone, several kinds of bacterial species were coaggregated. Film-like microcolonies were also observed in this zone. We detected filamentous microorganisms appeared to come out from the film-like colonies, and observed holes which microorganisms had been passed through the colonies. In the apical one-third zone, several kinds of bacterial species aggregated by glycocalyx-like structures, which comprised netlike and mucoidal structure. In the “plaque-free zone”, two types of bacterial colonization were observed : bacterial cell wall directly contacted with the root surface, and microorganisms adhered to the root surface mediated by glycocalyx netlike materials. In this zone, five periodontal disease-associated bacteria, including Porphyromonas gingivalis, were detected using back-scattered electron imaging modes. The results of the present study suggested that bacterial biofilms were partially related to colonization and growth of subgingival plaque.

Endodontic pathogens: propagation of infection through patent dentinal tubules in traumatized monkey teeth

Periapical pathology indicating endodontic infection, when present in marginal periodontitis-affected teeth, has recently been shown to be an aggravating factor in progression of marginal destruction. This has been associated with patency of dentinal tubules in the tooth cervix, an area normally devoid of cementum following periodontal therapy. These studies are, however hampered by that only circumstantial evidence such as presence of periapical destruction have been applied as criteria of endodontic infection. The purpose of the present investigation was to study to what extent a predefined selection of endodontic pathogens inoculated in the root canal can influence periodontal pathology and healing in areas of the root covered by or devoid of cementum, using root resorption as a histomorphometric marker. Exposed dentine surfaces, in the present study showed significantly larger areas of resorption in infected roots compared to non-infected roots, while cementum surfaces showed an almost identical distribution of tissue reactions regardless of root canal infection or not. It was concluded that endodontic pathogens or their products were not able to penetrate the cementum barrier. The significantly larger areas of resorption on exposed dentine surfaces in infected roots compared to non-infected roots indicated that endodontic pathogens or their products could spread through dentinal tubules to a root surface void of cementum. Extrapolated to the marginal situation this indicated that endodontic pathogens in the root canal might be able to aggravate marginal infection in areas of root devoid of cementum.

Endodontic pathogens in periodontal disease augmentation

Periapical pathology indicating endodontic infection, when present in periodontitis-affected teeth, has recently been shown to be correlated to marginal periodontal breakdown. This has been associated with patency of dentinal tubules in the tooth cervix, an area normally devoid of cementum following periodontal therapy. These studies are, however hampered by that only circumstantial evidence such as presence of periapical destruction have been applied as criteria of endodontic infection. The aim of the present investigation was to assess the effects of endodontic pathogens on marginal periodontal wound healing on root surfaces devoid of cementum but surrounded by healthy periodontal membrane. Significant differences between infected and non-infected teeth were found with respect to pathological pocket and connective tissue: The experimental defects were covered by approximately 20% more pocket epithelium in infected teeth while defects in non-infected teeth showed approximately 10% more connective tissue coverage. It was concluded, that an intra-canal infection of endodontic pathogens stimulates epithelial downgrowth along denuded dentin surfaces with marginal communication. Extrapolated to the clinical situation, endodontic infections in periodontitis-prone patients may augment periodontitis propagation.

Ultrastructure and Histochemistry of the Dental Cuticle in Adult Periodontitis

This study examined the dental cuticle (DC) at the interface with cementum surface, as well as its relationship to the overlying subgingival plaque (SP), the so-called plaque-free zone (PFZ), the junctional epithelium (JE), and the coronal fibers of the residual periodontal ligament (PL) by transmission electron microscopy (TEM) and histochemistry. Material comprised of 41 extracted, adult periodontitis-affected teeth (AP). Following extraction, 20 teeth were fixed in 3% glutaraldehyde in 0.1M sodium cacodylate, post-fixed in 1% osmium tetroxide, embedded in araldite, decalcified in EDTA, re-embedded in araldite, and sectioned. En bloc histochemistry was undertaken on the remaining 21 teeth, using ruthenium red, alcian blue-lanthanum nitrate, or safranin-O, and processed as above. Results show that the DC covered the cementum surface from the SP to the JE, and formed an interface with these structures. No DC was observed at the interface with PL. Morphological variations in DC surface were observed at the interface with the SP and at the so-called PFZ where bacteria were always in close contact with or surrounded by the DC. At the interface with JE, the DC appeared homogeneous, although layers varying in electron density were distinguishable. Teeth treated histochemically revealed a positive reaction of DC and bacteria to the three methods, suggesting the presence of anionic polymers including glycoproteins in the DC. It was concluded that on adult periodontitis affected teeth, the DC always covers exposed cementum and may mediate bacterial adhesion, and adsorb components from the periodontal pocket.

The "plaque-free zone" in health and disease: a scanning electron microscope study.

A "plaque-free" zone has been described on the enamel surface of healthy extracted teeth. This study examined this zone on chronic adult periodontitis-affected teeth (CAPT). Ten healthy controls and 16 CAPT were collected immediately after extraction, fixed, dehydrated, critical point dried, coated, and viewed by scanning electron microscopy (SEM). The "plaque-free" zone was observed in both groups as an area with few bacteria between the apical plaque border and the coronal limit of an epithelial layer on the root surface, extending to the residual periodontal ligament. On the healthy specimens, the apical plaque border consisted mainly of cocci and short rods, while on the CAPT specimens spirochetes predominated. Isolated or small groups of microorganisms were always present in the "plaque-free" zone and at its apical limit, close to or in contact with junctional epithelial cells. This zone is therefore not completely free of plaque, as suggested. It was concluded that a tissue complex, analogous to that in health on enamel, persists on the root surfaces of CAPT throughout the disease process. It comprises a discrete plaque border, a dental cuticle with sparse organisms, and an epithelium analogous to junctional epithelium. Its main function would appear to be to prevent bulk access of plaque to the surrounding tissues, including direct contact of bacteria with underlying ligament.

A combination of platelet‐derived and insulin‐like growth factors enhances periodontal regeneration

The combination of platelet-derived growth factor (PDGF) and insulin-like growth factor one (IGF-1) has previously been shown to enhance repair of soft tissue wounds. Here we report initial observations following application of PDGF and IGF-1 to periodontitis-affected teeth in beagle dogs. 1 micrograms of PDGF and IGF-1 in an aqueous gel was applied to the root surfaces of test teeth following open flap debridement. Control sites received the gel alone. Block biopsies of the teeth and surrounding bone were taken 2 weeks after treatment. Histologic analyses of control specimens revealed a long junctional epithelial attachment, and no new bone or cementum formation. In contrast, growth factor treated sites exhibited significant amounts of new bone and cementum formation. A nearly continuous layer of osteoblasts lined the newly formed bone, and there was a dense cellular "front" at the coronal extent of the new bone. These preliminary results suggest that in vivo application of the combination of PDGF and IGF-1 may enhance regeneration of the periodontal structures.

A gravimetric technique for measurement of denture hygiene.

Stem cell (SC) therapy is a promising technique for tissue regeneration. This study aimed to compare the viability and proliferation ability of periodontal ligament stem cells (PDLSCs) isolated from the periodontium of healthy and periodontitis-affected teeth to obtain an autologous, easily accessible source of SCs for tissue regeneration in periodontitis patients.The PDLSCs were isolated from the roots of clinically healthy premolars extracted for orthodontic purposes and periodontally involved teeth with hopeless prognosis (with and without phase I periodontal treatment). Cells were cultured and viability and proliferation ability of third passage cells in each group were evaluated using the methyl thiazol tetrazolium assay. The results were statistically analyzed using t-test.No SCs could be obtained from periodontitis-affected teeth without phase I periodontal treatment. The viability of cells was 0.86±0.13 OD/540 in healthy group and 0.4±0.25 OD/540 in periodontitis-affected group (P=0.035). The proliferation ability (population doubling time) of cells obtained from healthy teeth was 4.22±1.23 hours. This value was 2.3±0.35 hours for those obtained from periodontitis-affected teeth (P=0.02).Viability and proliferation ability of cells isolated from the periodontium of healthy teeth were significantly greater than those of cells isolated from the periodontitis-affected teeth.