Periodontitis: Inflammation and loss of connective tissues supporting or surrounding the teeth. This may involve any part of the PERIODONTIUM. Periodontitis is currently classified by disease progression (CHRONIC PERIODONTITIS; AGGRESSIVE PERIODONTITIS) instead of age of onset. (From 1999 International Workshop for a Classification of Periodontal Diseases and Conditions, American Academy of Periodontology)Chronic Periodontitis: Chronic inflammation and loss of PERIODONTIUM that is associated with the amount of DENTAL PLAQUE or DENTAL CALCULUS present. Chronic periodontitis occurs mostly in adults and was called adult periodontitis, but this disease can appear in young people.Aggressive Periodontitis: Inflammation and loss of PERIODONTIUM that is characterized by rapid attachment loss and bone destruction in the presence of little local factors such as DENTAL PLAQUE and DENTAL CALCULUS. This highly destructive form of periodontitis often occurs in young people and was called early-onset periodontitis, but this disease also appears in old people.Periapical Periodontitis: Inflammation of the PERIAPICAL TISSUE. It includes general, unspecified, or acute nonsuppurative inflammation. Chronic nonsuppurative inflammation is PERIAPICAL GRANULOMA. Suppurative inflammation is PERIAPICAL ABSCESS.Periodontal Pocket: An abnormal extension of a gingival sulcus accompanied by the apical migration of the epithelial attachment and bone resorption.Alveolar Bone Loss: Resorption or wasting of the tooth-supporting bone (ALVEOLAR PROCESS) in the MAXILLA or MANDIBLE.Periodontal Attachment Loss: Loss or destruction of periodontal tissue caused by periodontitis or other destructive periodontal diseases or by injury during instrumentation. Attachment refers to the periodontal ligament which attaches to the alveolar bone. It has been hypothesized that treatment of the underlying periodontal disease and the seeding of periodontal ligament cells enable the creating of new attachment.Porphyromonas gingivalis: A species of gram-negative, anaerobic, rod-shaped bacteria originally classified within the BACTEROIDES genus. This bacterium produces a cell-bound, oxygen-sensitive collagenase and is isolated from the human mouth.Gingiva: Oral tissue surrounding and attached to TEETH.Gingival Crevicular Fluid: A fluid occurring in minute amounts in the gingival crevice, believed by some authorities to be an inflammatory exudate and by others to cleanse material from the crevice, containing sticky plasma proteins which improve adhesions of the epithelial attachment, have antimicrobial properties, and exert antibody activity. (From Jablonski, Illustrated Dictionary of Dentistry, 1982)Gingival Hemorrhage: The flowing of blood from the marginal gingival area, particularly the sulcus, seen in such conditions as GINGIVITIS, marginal PERIODONTITIS, injury, and ASCORBIC ACID DEFICIENCY.Gingivitis: Inflammation of gum tissue (GINGIVA) without loss of connective tissue.Periodontal Index: A numerical rating scale for classifying the periodontal status of a person or population with a single figure which takes into consideration prevalence as well as severity of the condition. It is based upon probe measurement of periodontal pockets and on gingival tissue status.Dental Scaling: Removal of dental plaque and dental calculus from the surface of a tooth, from the surface of a tooth apical to the gingival margin accumulated in periodontal pockets, or from the surface coronal to the gingival margin.Aggregatibacter actinomycetemcomitans: A species of Gram-negative, facultatively anaerobic spherical or rod-shaped bacteria indigenous to dental surfaces. It is associated with PERIODONTITIS; BACTERIAL ENDOCARDITIS; and ACTINOMYCOSIS.Dental Plaque Index: An index which scores the degree of dental plaque accumulation.Dental Plaque: A film that attaches to teeth, often causing DENTAL CARIES and GINGIVITIS. It is composed of MUCINS, secreted from salivary glands, and microorganisms.Periodontium: The structures surrounding and supporting the tooth. Periodontium includes the gum (GINGIVA), the alveolar bone (ALVEOLAR PROCESS), the DENTAL CEMENTUM, and the PERIODONTAL LIGAMENT.Bacteroidaceae Infections: Infections with bacteria of the family BACTEROIDACEAE.Root Planing: A procedure for smoothing of the roughened root surface or cementum of a tooth after subgingival curettage or scaling, as part of periodontal therapy.Periodontal Diseases: Pathological processes involving the PERIODONTIUM including the gum (GINGIVA), the alveolar bone (ALVEOLAR PROCESS), the DENTAL CEMENTUM, and the PERIODONTAL LIGAMENT.Treponema denticola: A species of bacteria in the family SPIROCHAETACEAE, frequently isolated from periodontal pockets (PERIODONTAL POCKET).Prevotella intermedia: A species of gram-negative, anaerobic, rod-shaped bacteria originally classified within the BACTEROIDES genus. This bacterium is a common commensal in the gingival crevice and is often isolated from cases of gingivitis and other purulent lesions related to the mouth.Fusobacterium nucleatum: A species of gram-negative, anaerobic, rod-shaped bacteria isolated from the gingival margin and sulcus and from infections of the upper respiratory tract and pleural cavity.Actinobacillus Infections: Infections with bacteria of the genus ACTINOBACILLUS.Bacteroides: A genus of gram-negative, anaerobic, rod-shaped bacteria. Its organisms are normal inhabitants of the oral, respiratory, intestinal, and urogenital cavities of humans, animals, and insects. Some species may be pathogenic.Eikenella corrodens: Gram-negative bacteria isolated from infections of the respiratory and intestinal tracts and from the buccal cavity, intestinal tract, and urogenital tract. They are probably part of the normal flora of man and animals.Campylobacter rectus: A species of CAMPYLOBACTER isolated from cases of human PERIODONTITIS. It is a microaerophile, capable of respiring with OXYGEN.Subgingival Curettage: Removal of degenerated and necrotic epithelium and underlying connective tissue of a periodontal pocket in an effort to convert a chronic ulcerated wound to an acute surgical wound, thereby insuring wound healing and attachment or epithelial adhesion, and shrinkage of the marginal gingiva. The term is sometimes used in connection with smoothing of a root surface or ROOT PLANING. (Jablonski; Illustrated Dictionary of Dentistry, 1982)Root Canal Therapy: A treatment modality in endodontics concerned with the therapy of diseases of the dental pulp. For preparatory procedures, ROOT CANAL PREPARATION is available.Dental Pulp Necrosis: Death of pulp tissue with or without bacterial invasion. When the necrosis is due to ischemia with superimposed bacterial infection, it is referred to as pulp gangrene. When the necrosis is non-bacterial in origin, it is called pulp mummification.Treponema: A genus of microorganisms of the order SPIROCHAETALES, many of which are pathogenic and parasitic for man and animals.Actinobacillus: A genus of PASTEURELLACEAE described as gram-negative, nonsporeforming, nonmotile, facultative anaerobes. Most members are found both as pathogens and commensal organisms in the respiratory, alimentary, and genital tracts of animals.Peri-Implantitis: An inflammatory process with loss of supporting bone in the tissues surrounding functioning DENTAL IMPLANTS.Dental Calculus: Abnormal concretion or calcified deposit that forms around the teeth or dental prostheses.Pasteurellaceae: A family of coccoid to rod-shaped nonsporeforming, gram-negative, nonmotile, facultatively anaerobic bacteria that includes the genera ACTINOBACILLUS; HAEMOPHILUS; MANNHEIMIA; and PASTEURELLA.Gingivitis, Necrotizing Ulcerative: An acute or chronic GINGIVITIS characterized by redness and swelling, NECROSIS extending from the interdental papillae along the gingival margins, PAIN; HEMORRHAGE, necrotic odor, and often a pseudomembrane. The condition may extend to the ORAL MUCOSA; TONGUE; PALATE; or PHARYNX. The etiology is somewhat unclear, but may involve a complex of FUSOBACTERIUM NUCLEATUM along with spirochetes BORRELIA or TREPONEMA.Treponemal Infections: Infections with bacteria of the genus TREPONEMA.Tooth Cervix: The constricted part of the tooth at the junction of the crown and root or roots. It is often referred to as the cementoenamel junction (CEJ), the line at which the cementum covering the root of a tooth and the enamel of the tooth meet. (Jablonski, Dictionary of Dentistry, 1992, p530, p433)Matrix Metalloproteinase 8: A member of the MATRIX METALLOPROTEINASES that cleaves triple-helical COLLAGEN types I, II, and III.Occlusal Adjustment: Selective grinding of occlusal surfaces of the teeth in an effort to eliminate premature contacts and occlusal interferences; to establish optimal masticatory effectiveness, stable occlusal relationships, direction of main occlusal forces, and efficient multidirectional patterns, to improve functional relations and to induce physiologic stimulation of the masticatory system; to eliminate occlusal trauma; to eliminate abnormal muscle tension; to aid in the stabilization of orthodontic results; to treat periodontal and temporomandibular joint problems; and in restorative procedures. (From Jablonski, Dictionary of Dentistry, 1992)Gingival Recession: Exposure of the root surface when the edge of the gum (GINGIVA) moves apically away from the crown of the tooth. This is common with advancing age, vigorous tooth brushing, diseases, or tissue loss of the gingiva, the PERIODONTAL LIGAMENT and the supporting bone (ALVEOLAR PROCESS).Selenomonas: Curved bacteria, usually crescent-shaped rods, with ends often tapered, occurring singly, in pairs, or short chains. They are non-encapsulated, non-sporing, motile, and ferment glucose. Selenomonas are found mainly in the human buccal cavity, the rumen of herbivores, and the cecum of pigs and several rodents. (From Bergey's Manual of Determinative Bacteriology, 9th ed)Oral Hygiene Index: A combination of the debris index and the dental calculus index to determine the status of oral hygiene.Periapical Abscess: Acute or chronic inflammation of tissues surrounding the apical portion of a tooth, associated with the collection of pus, resulting from infection following pulp infection through a carious lesion or as a result of an injury causing pulp necrosis. (Dorland, 27th ed)Oral Hygiene: The practice of personal hygiene of the mouth. It includes the maintenance of oral cleanliness, tissue tone, and general preservation of oral health.Periodontal Ligament: The fibrous CONNECTIVE TISSUE surrounding the TOOTH ROOT, separating it from and attaching it to the alveolar bone (ALVEOLAR PROCESS).Bacteroidaceae: A family of gram-negative bacteria found primarily in the intestinal tracts and mucous membranes of warm-blooded animals. Its organisms are sometimes pathogenic.Maxillary DiseasesMouth Mucosa: Lining of the ORAL CAVITY, including mucosa on the GUMS; the PALATE; the LIP; the CHEEK; floor of the mouth; and other structures. The mucosa is generally a nonkeratinized stratified squamous EPITHELIUM covering muscle, bone, or glands but can show varying degree of keratinization at specific locations.Mouth: The oval-shaped oral cavity located at the apex of the digestive tract and consisting of two parts: the vestibule and the oral cavity proper.Tooth Loss: The failure to retain teeth as a result of disease or injury.Benzoylarginine-2-Naphthylamide: An enzyme substrate which permits the measurement of peptide hydrolase activity, e.g. trypsin and thrombin. The enzymes liberate 2-naphthylamine, which is measured by colorimetric procedures.Saliva: The clear, viscous fluid secreted by the SALIVARY GLANDS and mucous glands of the mouth. It contains MUCINS, water, organic salts, and ptylin.Alveolar Process: The thickest and spongiest part of the maxilla and mandible hollowed out into deep cavities for the teeth.Adhesins, Bacterial: Cell-surface components or appendages of bacteria that facilitate adhesion (BACTERIAL ADHESION) to other cells or to inanimate surfaces. Most fimbriae (FIMBRIAE, BACTERIAL) of gram-negative bacteria function as adhesins, but in many cases it is a minor subunit protein at the tip of the fimbriae that is the actual adhesin. In gram-positive bacteria, a protein or polysaccharide surface layer serves as the specific adhesin. What is sometimes called polymeric adhesin (BIOFILMS) is distinct from protein adhesin.Capnocytophaga: A gram-negative gliding bacterium isolated from the oral cavity. It is a pathogen often causing PERIODONTITIS.Bacteroides Infections: Infections with bacteria of the genus BACTEROIDES.Bacterial Load: Measurable quantity of bacteria in an object, organism, or organism compartment.Actinomyces: A genus of gram-positive, rod-shaped bacteria whose organisms are nonmotile. Filaments that may be present in certain species are either straight or wavy and may have swollen or clubbed heads.Papillon-Lefevre Disease: Rare, autosomal recessive disorder occurring between the first and fifth years of life. It is characterized by palmoplantar keratoderma with periodontitis followed by the premature shedding of both deciduous and permanent teeth. Mutations in the gene for CATHEPSIN C have been associated with this disease.Furcation Defects: Conditions in which a bifurcation or trifurcation of the molar tooth root becomes denuded as a result of periodontal disease. It may be followed by tooth mobility, temperature sensitivity, pain, and alveolar bone resorption.Dental Pulp Diseases: Endodontic diseases of the DENTAL PULP inside the tooth, which is distinguished from PERIAPICAL DISEASES of the tissue surrounding the root.Dental Prophylaxis: Treatment for the prevention of periodontal diseases or other dental diseases by the cleaning of the teeth in the dental office using the procedures of DENTAL SCALING and DENTAL POLISHING. The treatment may include plaque detection, removal of supra- and subgingival plaque and calculus, application of caries-preventing agents, checking of restorations and prostheses and correcting overhanging margins and proximal contours of restorations, and checking for signs of food impaction.Hemagglutinins: Agents that cause agglutination of red blood cells. They include antibodies, blood group antigens, lectins, autoimmune factors, bacterial, viral, or parasitic blood agglutinins, etc.Porphyromonas: A genus of gram-negative, anaerobic, nonsporeforming, nonmotile rods or coccobacilli. Organisms in this genus had originally been classified as members of the BACTEROIDES genus but overwhelming biochemical and chemical findings indicated the need to separate them from other Bacteroides species, and hence, this new genus was created.Root Canal Obturation: Phase of endodontic treatment in which a root canal system that has been cleaned is filled through use of special materials and techniques in order to prevent reinfection.Radiography, Bitewing: Technique involving the passage of X-rays through oral structures to create a film record while a central tab or wing of dental X-ray film is being held between upper and lower teeth.Tooth Apex: The tip or terminal end of the root of a tooth. (Jablonski, Dictionary of Dentistry, 1992, p62)Dental Pulp Cavity: The space in a tooth bounded by the dentin and containing the dental pulp. The portion of the cavity within the crown of the tooth is the pulp chamber; the portion within the root is the pulp canal or root canal.Case-Control Studies: Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.Antibodies, Bacterial: Immunoglobulins produced in a response to BACTERIAL ANTIGENS.Interleukin-1beta: An interleukin-1 subtype that is synthesized as an inactive membrane-bound pro-protein. Proteolytic processing of the precursor form by CASPASE 1 results in release of the active form of interleukin-1beta from the membrane.Peptostreptococcus: A genus of gram-positive, anaerobic, coccoid bacteria that is part of the normal flora of humans. Its organisms are opportunistic pathogens causing bacteremias and soft tissue infections.Aggregatibacter: A genus of PASTEURELLACEAE. Members are nonmotile, Gram-negative, facultatively anaerobic rods or coccobacilli. Its members are X factor (HEMIN) independent and variably dependent on V factor (NAD).Periodontics: A dental specialty concerned with the histology, physiology, and pathology of the tissues that support, attach, and surround the teeth, and of the treatment and prevention of disease affecting these tissues.Chronic Disease: Diseases which have one or more of the following characteristics: they are permanent, leave residual disability, are caused by nonreversible pathological alteration, require special training of the patient for rehabilitation, or may be expected to require a long period of supervision, observation, or care. (Dictionary of Health Services Management, 2d ed)Veillonella: A genus of gram-negative, anaerobic cocci parasitic in the mouth and in the intestinal and respiratory tracts of man and other animals.Prevotella: A genus of gram-negative, anaerobic, nonsporeforming, nonmotile rods. Organisms of this genus had originally been classified as members of the BACTEROIDES genus but overwhelming biochemical and chemical findings in 1990 indicated the need to separate them from other Bacteroides species, and hence, this new genus was established.Prevotella nigrescens: A species of gram-negative bacteria in the family Prevotellaceae. It is the species most commonly isolated from endodontic infections (PULPITIS).Bacteria: One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.Pulpectomy: Dental procedure in which the entire pulp chamber is removed from the crown and roots of a tooth.Gingival Pocket: An abnormal extension of a gingival sulcus not accompanied by the apical migration of the epithelial attachment.Periodontal Atrophy: Degradation or wasting of the PERIODONTIUM tissues that may involve the gum (GINGIVA), the alveolar bone (ALVEOLAR PROCESS), the DENTAL CEMENTUM, or the PERIODONTAL LIGAMENT.JordanPulpitis: Inflammation of the DENTAL PULP, usually due to bacterial infection in dental caries, tooth fracture, or other conditions causing exposure of the pulp to bacterial invasion. Chemical irritants, thermal factors, hyperemic changes, and other factors may also cause pulpitis.Periodontal Debridement: Removal or disruption of DENTAL DEPOSITS and plaque-retentive DENTAL CALCULUS from tooth surfaces and within the periodontal pocket space without deliberate removal of CEMENTUM as done in ROOT PLANING and often in DENTAL SCALING. The goal is to conserve dental cementum to help maintain or re-establish healthy periodontal environment and eliminate PERIODONTITIS by using light instrumentation strokes and nonsurgical techniques (e.g., ultrasonic, laser instruments).Statistics, Nonparametric: A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1284; Corsini, Concise Encyclopedia of Psychology, 1987, p764-5)Cysteine Endopeptidases: ENDOPEPTIDASES which have a cysteine involved in the catalytic process. This group of enzymes is inactivated by CYSTEINE PROTEINASE INHIBITORS such as CYSTATINS and SULFHYDRYL REAGENTS.Bacteroidetes: A phylum of bacteria comprised of three classes: Bacteroides, Flavobacteria, and Sphingobacteria.Prodigiozan: A polysaccharide extracted from Serratia marcescens and other bacteria. It activates enzymatic activity of macrophages and stimulates phagocytic processes.Periapical Diseases: Diseases of the PERIAPICAL TISSUE surrounding the root of the tooth, which is distinguished from DENTAL PULP DISEASES inside the TOOTH ROOT.Mouthwashes: Solutions for rinsing the mouth, possessing cleansing, germicidal, or palliative properties. (From Boucher's Clinical Dental Terminology, 4th ed)Bacterial Processes: The functions, behavior, and activities of bacteria.Mouth, Edentulous: Total lack of teeth through disease or extraction.Tooth, Nonvital: A tooth from which the dental pulp has been removed or is necrotic. (Boucher, Clinical Dental Terminology, 4th ed)Radiography, Panoramic: Extraoral body-section radiography depicting an entire maxilla, or both maxilla and mandible, on a single film.Apicoectomy: Excision of the apical portion of a tooth through an opening made in the overlying labial, buccal, or palatal alveolar bone. (Dorland, 28th ed)Mouth DiseasesPeriapical Granuloma: Chronic nonsuppurative inflammation of periapical tissue resulting from irritation following pulp disease or endodontic treatment.Dental Cementum: The bonelike rigid connective tissue covering the root of a tooth from the cementoenamel junction to the apex and lining the apex of the root canal, also assisting in tooth support by serving as attachment structures for the periodontal ligament. (Jablonski, Dictionary of Dentistry, 1992)Mandibular DiseasesTooth Abnormalities: Congenital absence of or defects in structures of the teeth.Biofilms: Encrustations, formed from microbes (bacteria, algae, fungi, plankton, or protozoa) embedding in extracellular polymers, that adhere to surfaces such as teeth (DENTAL DEPOSITS); PROSTHESES AND IMPLANTS; and catheters. Biofilms are prevented from forming by treating surfaces with DENTIFRICES; DISINFECTANTS; ANTI-INFECTIVE AGENTS; and antifouling agents.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Bone Resorption: Bone loss due to osteoclastic activity.Calcium Hydroxide: A white powder prepared from lime that has many medical and industrial uses. It is in many dental formulations, especially for root canal filling.