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PERIODONTICS 1 DPER 421 | Dr. Sheila May Dee | Lecture | 1st SEMESTER A.Y 2021-2022 WEEK 2 – ANATOMY AND PHYSIOLOGY OF THE PERIODONTIUM BIOLOGY OF THE PERIODONTIUM The Oral Mucosa Consists of Three Zones:...

PERIODONTICS 1 DPER 421 | Dr. Sheila May Dee | Lecture | 1st SEMESTER A.Y 2021-2022 WEEK 2 – ANATOMY AND PHYSIOLOGY OF THE PERIODONTIUM BIOLOGY OF THE PERIODONTIUM The Oral Mucosa Consists of Three Zones: CHAPTER OUTLINE Masticatory Mucosa Clinical Features - gingiva and covering of the hard palate o Marginal Gingiva o Gingival Sulcus Specialized Mucosa o Attached Gingiva - covers the dorsum of the tongue o Interdental Gingiva Oral Mucous Membrane Microscopic Features - lines the remainder of the oral cavity. floor of o Gingival Epithelium the mouth, ventral side of the tongue, cheeks, o Gingival Connective Tissue lip, and soft palate Correlation of Clinical and Microscopic Features GINGIVA o Color ▪ The gingiva is the part of the oral mucosa that o Size o Contour covers the alveolar process of the jaws and o Shape surrounds the cervical portion of the teeth. o Consistency ▪ Soft tissues that serve as a barrier which o Surface prevents microorganisms from entering the o Texture gingival connective tissue o Position ▪ There is no mucogingival line present in the palate since the hard palate and the maxillary alveolar process are covered by the same type of masticatory mucosa. MARGINAL GINGIVA ▪ Also known as Unattached gingiva, Free gingiva ▪ Coral pink, has a dull surface and firm consistency. It extends from the gingival margin to the gingival groove ▪ The terminal edge or border of the gingiva surrounding the teeth in collar like fashion. PERIODONTIUM - also called “the attachment apparatus” or “the supporting tissues of the teeth.” - main function is to attach the tooth to the bone tissue of the jaws and to maintain the integrity of the surface of the masticatory mucosa of the oral cavity. AUBREY T. |DMD4Y1-3|1|9 FREE GINGIVAL GROOVE ATTACHED GINGIVA ▪ In 50% of the cases, it is demarcated from the ▪ Attached firmly to alveolar bone; varies in width adjacent, attached gingiva by a shallow linear ▪ Extends from the free gingival groove unto the depression, the free gingival groove. mucogingival junction. ▪ It may be separated from the tooth surface with ▪ It is firm, resilient, and tightly bound to the a periodontal probe. underlying periosteum of alveolar bone. ▪ Positioned at a level corresponding to the level ▪ Demarcated from the adjacent loose and of the CEJ moveable alveolar mucosa by the mucogingival ▪ Only present in 30-40% of adults junction. ▪ Width of the attached gingiva is the distance between the mucogingival junction and the projection on the external surface of the bottom of the gingival sulcus or the periodontal pocket. ▪ Generally greatest at the incisor region and less in the posterior segments, with the least width at the premolar area. GINGIVAL SULCUS ▪ Changes in width are caused by modifications in the position of its coronal end. ▪ The shallow crevice or space around the tooth ▪ It increases with age and supra-erupted teeth. bounded by the surface of the tooth on one ▪ Palatal surface in the maxilla blends side and the epithelium lining the free margin imperceptibly with the palatal mucosa. of the gingiva on the other. ▪ Physiologically, if attached gingiva is absent, ▪ V shaped food can cause friction on mucosa which will ▪ The so-called probing depth of a clinically lead to recession. normal gingival sulcus in humans is 2-3mm. ▪ In pristine conditions, the gingival sulcus does NOT exist. ▪ After completed tooth eruption, the free gingival margin is located on the enamel surface approximately 1.5-2mm coronal to the CEJ. INTERDENTAL GINGIVA ▪ Occupies the gingival embrasure, which is the interproximal space beneath the area of tooth contact. ▪ Can be pyramidal or have a “col” shape ▪ Pyramidal - the tip on one papilla is located immediately beneath the contact point ▪ Col -presents a valleylike depression that connects a facial and lingual papilla and conforms to the shape of the inter proximal contact. AUBREY T. |DMD4Y1-3|2|9  MICROSCOPIC ANATOMY GINGIVAL EPITHELIUM ▪ Three different areas of the gingival epithelium ▪ The boundary between the oral epithelium and underlying connective tissue has a wavy course. The connective tissue portions which project into the epithelium are called connective tissue papilla and are separated from each other by epithelial ridges (rete pegs) ▪ Oral Epithelium and oral sulcular epithelium has rete pegs. ▪ Rete pegs are lacking in the junctional epithelium ORAL EPITHELIUM Stippling − Faces the oral cavity − Lined by keratinized, stratified squamous - orange peel epithelium - varies with age. Absent in infancy, appears in − Principal cell type is the keratinocyte which some children at about 5 years of age, increases undergoes proliferation and differentiation. until adulthood, and frequently begins to − Main function is to protect the deep structures disappear in old age. while allowing a selective interchange with the - feature of a healthy gingiva oral environment - reduction or loss of stippling is a common sign − Proliferation of keratinocytes - takes place by of gingival disease. mitosis in the basal layer and less frequently in the supra basal layers − Differentiation of keratinocytes - involves the process of keratinization − Keratinocytes are attached with each other thru desmosomes − Desmosomes - also known as macula adherens a cell structure specialized for cell to cell adhesion consists of two adjoining CLINICALLY HEALTHY GINGIVA hemidesmosomes − Hemidesmosomes - involved in the attachment ▪ Microorganisms are present and could be still of the epithelium to the underlying basement inflamed. membrane ▪ Marginal gingiva is scalloped, following the CEJ; posterior, less scalloping, fills up the embrasures; closely adapted to tooth structure; consistency (firm and immobility for attached gingiva); presence of stippling (orange peel appearance which is present in 40-60% of population; dependent on rete pegs) AUBREY T. |DMD4Y1-3|3|9  Composed of 4 layers: − The cytoplasm of the cells is filled 1. Basal cell layer (Stratum basale with keratin. /germinativum) − The entire apparatus for protein − Stratum basale or stratum synthesis is lost. (nucleus, germinativum mitochondria, endoplasmic reticulum, − Cells are either cylindric or cuboidal golgi apparatus) and are in contact with the basement membrane. − Possess the ability to divide (undergo mitotic cell division. − Considered as the progenitor cell compartment of the epithelium. − Very prominent round nucleus; organelles present 2. Spinous cell layer (Stratum spinosum) − Stratum spinosum − Consists of 10-20 layers of relatively polyhedral cells, equipped with short cytoplasmic processes resembling spines. − Presence of large number of desmosomes indicating that the cohesion between the epithelial cells Basal Lamina is solid. − Nucleus is smaller, organelles are still − Basement membrane present − Interface between the oral epithelium and the lamina propria 3. Granular cell layer (Stratum granulosum) − Lamina Densa - composed of type iv collagen − Stratum granulosum − Lamina Lucida - composed of glycoprotein − Electron dense keratohyalin bodies laminin and clusters of glycogen-containing Lamina Propria granules start to occur. − The tonofilaments in the cytoplasm − consists of loose connective tissue within the and the number of desmosomes connective tissue papillae, along with blood continue to increase. vessels and nerve tissue − There is a decrease in the number of − the predominant tissue component of the organelles (mitochondria, lamellae of gingiva rough endoplasmic reticulum, golgi − composed of: apparatus) in the keratinocytes − 60% collagen fibers − Flattened nucleus, seems like cell is − 5% fibroblasts dying − 35% vessels and nerves 4. Keratinized cell layer (Stratum corneum) − Stratum corneum or cornified layer − There is a very sudden keratinization of the cytoplasm of the keratinocyte. AUBREY T. |DMD4Y1-3|4|9  TYPES OF COLLAGEN MOLECULAR CELLS MAJOR FUNCTION TYPE SYNTHESIZING LOCATIONS IN BODY I Fibroblast Dermis of Resists Osteoblast skin, bone, tension Odontoblast tendons, ligaments, fibrocartilage II Chondroblast Hyaline Resists cartilage intermittent pressure III Fibroblast Lymphatic Forms Reticular cell system, structural Smooth cardiovascular framework muscle system, liver, in Schwann cell lung, spleen, expandable Hepatocyte intestine, organs uterus, endoneurium IV Endothelial cell Basal lamina Provides Epithelial cell External lamina support and Muscle cell filtration Schwann cell Acts as scaffold for cell migration V Mesenchymal Placenta Unknown cell Dermal- epidermal junction Orthokeratinized VII Keratinocyte Dermal- Forms epidermal anchoring - absence of nuclei in the stratum corneum, has a well- junction fibrils that defined stratum granulosum secure lamina Parakeratinized densa to - the stratum corneum contains pyknotic nuclei. underlying Keratohyalin granules are dispersed, absence of stratum connective tissue granulosum Non-keratinized Morphologic changes: - superficial cells has visible nuclei, absence of stratum − Progressive flattening of the cell granulosum and stratum corneum. − increased number of tonofilaments and intercellular junctions − production of hyaline granules disappearance of nucleus. AUBREY T. |DMD4Y1-3|5|9  CELLS OF THE GINGIVAL EPITHELIUM − formed by the union of the oral epithelium ▪ Keratinocyte - principal cell type and the reduced enamel epithelium during ▪ Nonkeratinocytes (clear cells) tooth eruption. o Langerhans cells - believed to play a role in the defense mechanism of the oral mucosa. - they react with antigens which are in the process of penetrating the epithelium. - antigen presenting cells for lymphocytes found mostly at the basal layer o Merkel cells - located in the basal layers - connected to adjacent cells by CONNECTIVE TISSUE desmosomes they harbor nerve endings DIFFERENT TYPES OF CELLS PRESENT - identified as tactile perceptors FIBROBLAST o Melanocytes - located in the basal layers ▪ Predominant CT cell (65%) - synthesis of melanin pigment ▪ Engaged in the production of various types of fibers found in the CT, but is also instrumental in the synthesis of the CT matrix SULCULAR EPITHELIUM MAST CELLS − faces the tooth without being in contact with the tooth surface ▪ Host defense mechanism − lines the gingival sulcus ▪ Produces vasoactive substances which can − thin, nonkeratinized stratified squamous affect the function of the microvascular system epithelium without rete pegs and control the flow of blood through the − extends from the coronal limit of the tissue. junctional epithelium to the crest of the gingival margin. − It lacks stratum granulosum and stratum MACROPHAGE corneum. ▪ Phagocytic and synthetic functions JUNCTIONAL EPITHELIUM ▪ Phagocytose foreign bodies/chemicals numerous in inflamed tissues − provides the contact between the gingiva ▪ Derived from circulating blood monocytes and the tooth. − composed of basal and spinous cell layers − consists of a collar like band of stratified NEUTROPHILIC GRANULOCYTES squamous nonkeratinizing epithelium without rete pegs ▪ Also called polymorphonuclear leukocytes − It lacks stratum granulosum and stratum ▪ Scarce in normal tissue/gingiva corneum. AUBREY T. |DMD4Y1-3|6|9 LYMPHOCYTES and PLASMA CELLS MAJOR COLLAGEN FIBER GROUPS ▪ Influence the behavior of the overlying CIRCULAR FIBERS epithelium by releasing of cytokines ▪ Dependent on the nature and duration of injury ▪ Encircles neck of root ▪ Maintains position of free gingiva TYPES OF CONNECTIVE TISSUE FIBERS DENTOGINGIVAL FIBERS COLLAGEN FIBERS ▪ Embedded in the cementum and projects ▪ Most essential component of the periodontium out/towards the free gingiva. ▪ Cementoblasts and osteoblasts are cells which also possess the ability to produce collagen. DENTOPERIOSTEAL FIBERS ▪ Embedded in the cementum and projects RETICULIN FIBERS towards the periosteum of alveolar bone ▪ Located near the blood vessels TRANSSEPTAL FIBERS ▪ Embedded in the cementum of approximating OXYTALAN FIBERS teeth ▪ Located in the apical region ▪ Distal side of tooth and to the medial of the ▪ Scarce in the gingiva but numerous in the other periodontal ligament  Section through gingival connective tissue in which GINGIVAL GROOVE oxytalan fibers can be found mixed in among - prominent in the dentogingival and dento periosteal collagen fibers. fibers.  Legends: - CF, type I collagen fibrils GINGIVAL FLUID - OF, oxytalan fibrils ▪ Aka gingival crevicular fluid (GCF) or sulcular - Close fluid ▪ Contains antibodies, immunoglobulins, plasma cells, and pmns. Increased in the presence of ELASTIC FIBERS gingival inflammation ▪ Only present in association with blood vessels. ▪ It is believed to: o Cleanse material from the sulcus AUBREY T. |DMD4Y1-3|7|9  o Contain plasma proteins that may INTERRADICULAR FIBERS improve adhesion of the epithelium to the tooth − fan out from the cementum to the tooth in o Possess antimicrobial properties furcation areas of multi-rooted teeth. o Exert antibody activity to defend the gingiva PERIODONTAL LIGAMENT ▪ CT that surrounds the root and connects it to the bone ▪ Has the shape of an hourglass and is narrowest at the mid root level. ▪ Width is approximately 0.25mm ▪ Distributes the force elicited during mastication. Essential for mobility of the teeth. Sharpey’s Fibers PRINCIPAL FIBERS OF THE PERIODONTAL LIGAMENT ▪ Terminal portions of the principal fibers that insert into cementum and bone. ALVEOLAR CREST FIBERS − Extend obliquely from the cementum just beneath the junctional epithelium to the alveolar crest − Prevent extrusion of the tooth and resists lateral tooth movement HORIZONTAL FIBERS − Extend at right angles to the long axis of the CEMENTUM tooth from the cementum to the alveolar bone ▪ Specialized mineralized tissue covering the root OBLIQUE FIBERS surfaces and occasionally, small portions of the crown of the teeth. − Largest group in the periodontal ligament ▪ Has no blood or lymph vessels, no innervation, − Extends from the cementum in a coronal does not undergo physiologic resorption or direction obliquely to the bone. remodeling. − They bear the impact of masticatory stresses ▪ Characterized by continuous deposition and transform them in a tension on the alveolar throughout life. bone. ▪ Attaches the periodontal ligament fibers to the root. APICAL FIBERS ACELLULAR CEMENTUM − Radiate in an irregular fashion from the cementum to the bone at the apical region of ▪ Acellular, afibrillar cementum the socket. o without any cell (collagen fibrils or − Do not occur on incompletely formed roots cementocytes) in its matrix o coronal cementum AUBREY T. |DMD4Y1-3|8|9  ▪ Acellular, extrinsic fiber cementum o with well-defined, type I collagen fibrils (part of Sharpey’s fibers) o found in coronal 2/3 of the root o primary cementum o connects the tooth with the alveolar bone proper CELLULAR CEMENTUM ▪ Secondary cementum ▪ found in apical 1/3 of root and in the furcations CEMENTOBLASTS OSTEOBLASTS − Cementum forming cells − Bone forming cells CEMENTOCYTES OSTEOCLASTS − Cementoblasts trapped in the cementum matrix − Giant cells specialized in the breakdown of mineralized matrix (bone, dentin, cementum) ALVEOLAR BONE OSTEOCYTES ▪ Parts of the maxilla and the mandible that form − Stellate shaped cells that are trapped within the and support the sockets of the teeth. mineralized bone matrix ▪ Composed of: − Participates in the blood calcium homeostasis o Cortical bone o Alveolar bone proper DEHISCENCE VS FENESTRATION CORTICAL BONE DEHISCENCE − Compact bone - when the bone at the coronal portion of the − Part of the alveolar bone that covers the root is missing. alveolus. FENESTRATION − Appears on the radiograph as the lamina dura - an area of denuded bone, surrounded by an intact bone ALVEOLAR BONE PROPER *** in both cases, the root is covered only by − Spongy bone periodontal ligament and the overlying gingiva. − Has many lacunae active for blood forming − Appears on the radiograph as meshwork AUBREY T. |DMD4Y1-3|9|9  PERIODONTICS 1 DPER 421 | Dr. Sheila May Dee | Lecture | 1st SEMESTER A.Y 2021-2022 WEEK 3: EPIDEMIOLOGY OF PERIODONTAL DISEASES EPIDEMIOLOGY − A disease is deemed eradicated when no new − The study of the distribution of a disease or a case is reported 2 years after herd physiologic condition in human population and of immunization the factors that influence this distribution 4. It contributes to the planning, monitoring and evaluation of health services (to know which disease  Epi - among/against to focus on)  Demos - population, people 5. It serves as a key instrument in the formulation of  Logos - study health policies i. Ex. Seaman - before leaving the 3 COMPONENTS OF EPIDEMIOLOGY country, they have to undergo HIV 1. Population - defined by testing a. geographic boundaries (racial) b. characteristics or attributes (age, old, or Epidemiologic Researches are used in Periodontics young group) 1. Provide data on the prevalence of periodontal 2. Distribution - normal distribution diseases in different populations 2 3. Factors - ex. dependent and independent variables, 2. Elucidates aspects related to the etiology and the confounders, exposure variables determinants of development of these diseases − determinants: risk or modifying AIM OF EPIDEMIOLOGY − there are risk factors that can be modified 1. Prevention of Disease (Control of disease) (eg. lifestyle)  Ex. SARS, Birdflu, MERS-Cov 3. Provide documentation concerning the effectiveness 2. Maintenance of health (promotion of health) of preventive therapeutic measures against diseases − Basically organizing gathered information for it to be useful Demographic Factors in the Prevalence of Periodontal − The dilemma in epidemiology is pendulum Disease  Ex. alcohol consumption before is bad but A. Age now, because of pendulum swings, red wine − more severe periodontal problems for older is said to be good for our health patients B. Sex SCOPE OF EPIDEMIOLOGY − male has higher prevalence for periodontal ▪ Part of it is research disease ▪ It can be used in every aspect of our lives C. Race − Caucasians have better health programs USES OF EPIDEMIOLOGY D. Nutrition 1. It can identify and measure the importance of health − those with immune response are more problems prone to diseases − Prevalence and morbidity: E. Socio-economic Status i. Ex. Tb - knowing the extent of this − poor are less likely to afford things to problem, allotment of budget is maintain good health so more prone to considered disease 2. For understanding the natural history of disease − For us to know how to prevent and control the STUDY DESIGNS USED IN EPIDEMIOLOGY disease. ▪ Descriptive Studies − Ex: perio disease progression: classical vs. Burst ▪ Analytical Studies model o Observational studies 3. It is essential for disease surveillance and control o Experimental Studies − Disease control: vaccination - eradicate the disease AUBREY T. |DMD4Y1-3 | pg. 1 DESCRIPTIVE STUDIES DISCLOSING SOLUTION − Characterizes disease occurrence − Provide clues regarding etiology − Useful for formulating hypothesis − Just describes the phenomena − Tools: o Case Studies (simplest form) o Case Series (can hypothesize) o Cross Sectional Studies PERIODONTAL INDEX ANALYTICAL STUDIES − by Russel, 1956 − Focuses in gingivitis and also considers pocketing Observational Studies and mobility − Simply observes the natural course of events (no intervention, no control) Score 0 Healthy − Tools: Score 1 Gingivitis but not on whole gingival margin o Cross Sectional Studies of tooth o Cohort Studies (from exposure then look for Score 2 Gingival inflammation along the cervical the outcome) margin encircling the tooth o Case-Control Studies (reverse of cohort, for Score 6 Periodontal pocketing, bone loss Score 8 With excessive mobility rare diseases, basic problem: case definition, denominator) PLAQUE INDEX (PI) Experimental Studies (Intervention) − by Silness and Loe − May prove causal association − The most important consideration is the thickness of − May lead to development of new hypothesis plaque along the gingival margin, because only this − Tools: plaque in direct contact with the gingival tissue plays o Clinical Trials (expensive, only involves a small any role in the etiology of gingivitis. group of people) − Plaque is not stained, it is visualized by air drying o Community Trials (succeeds clinical trials if − Problem: subjective, what is moderate? clinical is effective) − Relatively time consuming ▪ involves the entire community ▪ factors: accessibility, cost, culture Score 0 No plaque Score 1 Thin film of plaque at the gingival margin, INDICES USED IN PERIODONTAL DISEASE STUDIES visible only when scraped with an explorer Score 2 Moderate amount of plaque along the  Different indices measure different factors gingival margin; interdental space free of − Periodontal Index by Russel (1956) plaque; plaque visible with the naked eye − Oral Hygiene Index (OHI) by Greene and Vermillion Score 3 Heavy plaque accumulation at the gingival (1960) margin; interdental space filled with plaque − Plaque Index (PI) of Silness and Loe − Interdental Hygiene Index (HYG) INTERDENTAL HYGIENE INDEX − Hygiene Index (HI) − It records plaque-free surfaces as a percentage − Sulcus Bleeding Index (SBI) − After staining, a simple yes/no decision is made with − Gingival Index (GI) regard to whether or not stained plaque is present − Gingival Index Simplified (GI-S, Lindhe 1981) and (+) or not (-). Gingival Bleeding Index (GBI, Alnamo, 1975) − Usually scored with a quadrant from only one aspect. − Papilla Bleeding Index (PBI) i.e.., from the facial or from the oral − Ramfjord teeth − It is a sensitive index because small plaque quantity is − Periodontal Disease Index (PDI) also measured and because the index is scored in the − CPITN (Community Periodontal Index of Treatment interdental areas, which are in most cases not Needs) particularly cleaned. − Not used in epidemiological studies because it is time consuming AUBREY T. |DMD4Y1-3 | pg. 2  HYG = Number of plaque free areas (-) x 100 Grade 0 No bleeding on probing number of examined areas Grade 1 Bleeding on probing, no changes in color or contour Grade 2 Bleeding on probing, eryhtema Grade 3 Bleeding on probing, erythema, mild edema Grade 4 Bleeding on probing, erythema, severe edema Grade 5 Bleeding on probing/spontaneous hemorrhage, severe edema with or without ulceration GINGIVAL INDEX (GI) − Silness and Loe, 1963 − Scores gingival inflammation on the facial, lingual, HYGIENE INDEX (HI) and medial surfaces of all teeth − Recording plaque accumulation on all tooth surfaces − The symptom of bleeding comprises a score of 2 − this most precise index involves measurement of − Used worldwide in epidemiological studies and plaque accumulation on all four tooth surfaces scientific investigations (facial, oral, mesial, distal) − Less applicable for individual patients because the − A simple yes/no decision: dichotomous differences between the scoring levels are too gross − Problem: loss of information because it can’t determine the degree of plaque accumulation which Grade 0 Normal gingiva, no inflammation, no can tell who is more prone or susceptible discoloration, no bleeding − Was developed solely for use in individual patients Grade 1 Mild inflammation, slight color change, mild alteration of gingival surface, no bleeding Grade 2 Moderate inflammation, erythema, swelling, bleeding on probing or when pressure is applied Grade 3 Severe inflammation, severe erythema and swelling, tendency toward spontaneous hemorrhage, some ulceration GINGIVAL INDEX SIMPLIFIED (GI-S, LINDHE 1981) AND GINGIVAL BLEEDING INDEX (GBI, AINAMO, 1975) − All four tooth surfaces are scored as (+) or (-) for bleeding on probing. − Negative observations are not entered into the chart. SULCUS BLEEDING INDEX (SBI) − Gingivitis incidence is calculated as a percentage of affected (bleeding) units. − Muhlemann and Son, 1971 − Suited only for individual practice application on a − Considers bleeding from the sulcus after probing, as routine basis. well as erythema, swelling and edema − Used as an indicator of gingival health, no bleeding PAPILLA BLEEDING INDEX (PBI) (healthy) − Has been used in various clinical studies but is also − By Saxer and Muhlemann, 1975 applicable to individual patients in a private practice − Permits both immediate evaluation of the patient’s setting gingival condition and his motivation, based upon − Generally scored separately from both the papilla (P) the actual bleeding tendency of the gingival papillae. and margin (M) AUBREY T. |DMD4Y1-3 | pg. 3  Grade 1 Point PERIODONTAL DISEASE INDEX (PDI) 20-30 seconds after probing, the − Contains a gingivitis index in scores 1, 2, and 3, and a medial and distal sulcus with a measure of attachment loss independent of periodontal probe, a single gingivitis, in scores 4, 5, and 6 bleeding is observed − Designed for use in epidemiological studies, not for Grade 2 Linear/multiple pinpoint clinical practice A fine line of blood or several − Development using the Ramfjord teeth bleeding points become visible at the gingival margin Grade 3 Triangular bleeding Score 0 No inflammation, no alterations in the The interdental triangle becomes gingiva more or less filled with blood Gingiva Grade 4 Drops/pooling Score 1 Mild to moderate gingivitis at some Profuse bleeding. Immediately locations on the gingival margin after probing, blood flows into the Score 2 Mild to moderate gingivitis of the entire interdental area to cover portions gingival margin surrounding the tooth of the tooth or gingiva. Score 3 Advanced gingivitis with severe erythema, hemmorage, ulceration Periodontium Score 4 Up to 3mm of attachment loss, measured from CEJ Score 5 3-6mm of attachment loss Score 6 More than 6mm of attachment loss COMMUNITY PERIODONTAL INDEX OF TREATMENT NEEDS (CPITN) − Developed by Ainamo et.al. (1982) at the initiative of WHO − Designed to determine the treatment for a RAMFJORD TEETH community − For epidemiological purposes, six teeth could be − Was used to determine prevalence taken as representative of the entire dentition 1. Divide dentition into sextants with at least 2 teeth (sextant) present on each sextant − Use partial assessment 2. Probing assessments are performed with the most − Take the worst condition to represent the sextant severe measurement chosen to represent the sextant. − Less time consuming 3. Periodontal conditions are scored as follows Code 0 Gingival health Code 1 No pockets, overhangs and calculus but with bleeding after probing Code 2 Pockets not exceeding 3mm, but with plaque retaining factors seen located gingival Code 3 With 4 to 5mm deep pockets Code 4 With pockets 6mm deep or greater 4. Treatment needs are scores based on the most severe score in dentition TN 0 Gingival health TN 1 Need for improved oral hygiene (Code 1) TN 2 Need for scaling and removal of overhangs and improved oral hygiene (Code 2 and 3) TN 3 Indicating complex treatment (Code 4) AUBREY T. |DMD4Y1-3 | pg. 4 − Disputed by Baelum − Reasons: 1. Calculus was the etiology 2. Code 4 - surgery aided, treatment was constricted to specifics resulting to over treatment 3. Use of index teeth ▪ doesn’t represent all dentition. ▪ overestimates for young people in prevalences 4. Pocket depth ▪ not stable. measures soft tissue. ▪ Affected by: marginal inflammation, force applied, size of probe, etc., ▪ It is reversible ▪ CEJ to attachment base - a more stable measure AUBREY T. |DMD4Y1-3 | pg. 5  Clinical Parameters In Periodontal Diagnosis Periodontal Photographic Documentation Examination & Diagnosis: Clinical Examination Overall Appraisal Of The Patient Tactile Periodontal Examination Health History Dental History Photographic Documentation Visual Examination Clinical Examination Tactile Periodontal Examination ❖ Morphological Alterations Evident Periodontal Charting Color (Coral Pink), Form Examination Of The Teeth (And (Triangular/Knife Edge) Implants) Radiographic Examination ❖ Check For Disease With Periodontal Laboratory Aids To Clinical Diagnosis Manifestations (Plaque / Non Plaque Periodontal Diagnosis Induced) Assessment Of Biofilm Control And ❖ Oral Hygiene Status (Amount Of Patient Education Plaque On The Tooth Surfaces, Distribution And Localization) Overall Appraisal Of The Patient Interdental Cleaning, Consider The Patient’s: Toothbrushing Mental And Emotional Status Temperament Attitude Physiologic Age Health History ❖ Importance Of Health Hx (1) The Possible Impact Of Certain Systemic Diseases, Conditions, Behavioral Factors, And Medications On Clinically Healthy Gingiva Periodontal Disease, Its Treatment, And Treatment ❖ Color: Coral Pink Or Salmon Pink Outcomes; ❖ Consistency: Firm/Tight, Well (2) The Presence Of Adapted Conditions That May Require ❖ Contour: Scalloped, Sharp Papillae, Special Precautions Or Knife-Edge Margin Modifications Of The ❖ Surface Texture: Matte, Stippled Treatment Procedure; And ❖ Marginal Bleeding: Absent Or Slight (3) The Possibility That Oral ❖ Probing Depth: 2-3 Mm Infections May Have A ❖ Tissue Resistance: Present To Probe Powerful Influence On The Penetration Occurrence And Severity Of A ❖ Bleeding On Probing: Absent Or Variety Of Systemic Diseases Slight And Conditions ❖ Pain Or Probing: Absent Or Slight Chief Complaint And Inflamed Gingiva History Of Present Illness Dental History ❖ Color: Erythematous, Cyanotic ❖ Consistency: Edematous, Spongy, Loosely Adapted  ❖ Contour: Bulbous, Swollen Papillae, Rolled Margins ❖ Surface Texture: Smooth, Shiny ❖ Marginal Bleeding: Moderate Or Severe ❖ Probing Depth: >3 Mm ❖ Tissue Resistance: Minimal To Probe Penetration ❖ Bleeding On Probing: Moderate To Severe ❖ Pain Or Probing: Moderate To Severe Periodontal Charting ❖ When Probing, The Probe Tip Should Be In Contact With The Tooth Surface Pocket Probing Depth As It Slides Down Along The Tooth Surface To Get To The Bottom Of The ❖ Does Not Reveal The True Picture Of Gingival Crevice. This Allows For Attachment Detection Of: ❖ Distance From The Gingival Margin To Tooth Surface Irregularities, The Bottom Of The Pocket. Furcation Invasion, And ❖ Measured On All Surfaces Using A Subgingival Calculus. Graduated Probe On 6 Sites (Like Walking Or Sweeping) Bleeding On Probing ❖ Record The Deepest Reading Per Site ❖ Important Indicator Of Presence Of ❖ Insert Probe Until There Is Resistance Inflammation ❖ Does Not Reveal Disease Progression ❖ Indicator Of Absence Of Burst ❖ Does Not Indicate Possible Burst ❖ Burst - Active Loss Of Connective Tissue Attachment. Best Time To Intervene. ❖ Absence Of Bleeding Is A Sign Of Stability And Health (If There Is No Bop, There Is 0 Chance Of Factors Which Affect Probing Attachment Loss) ❖ Dimensions Of Perio Probe - (Tip 0.4 ❖ Severity Of Bleeding To 0.5mm) If Greater, Can Be Pinpoint Uncomfortable To Patient Thin Linear Or Multiple ❖ Position Of The Probe - Parallel To The Pinpoint Long Axis Of The Tooth. Triangular ❖ Reference Point Location Droplets Or Pooling Gingival Margin: Clinically Healthy - At The Level Of Cej Papillary Bleeding Index Inflamed - Coronal To Cej Gingival Recession - Apical To Cej ❖ Pressure On The Instrument Force 20-25g  Less Than 20-25 G (Inadequate Force/No Infrabony Pocket (Intrabony, Subcrestal Or Bleeding) Intraalveolar) More Than 20-25 G (Bleeding Due To The Force/Trauma) ❖ Base / Bottom Of Pocket Is Apical To ❖ Gingival Tissue Conditions Adjacent Alveolar Crest If Collagen Is Firm, There ❖ Simple, Compound , Complex Would Be Underestimation ❖ The Bone Loss Is Vertical In Nature Beyond Je - Overestimation 3 Walled, 2 Walled, 1 Walled ❖ Presence Of Surface Accretions Defects Presence Of Calcular Deposits, Overhanging Restorations Treatment - Perform Initial Scaling,Remove Overhanging Restorations Types Of Pockets ❖ Normal Gingival Sulcus Types Of Infrabony Pockets Apical Termination Of Je Is At The Cej Two Wall Bony Defect ❖ Periodontal Pocket 0.5mm Depth (Pristine) 2-3mm Normal Ppd ❖ Pseudopocket Created By Gingival Enlargement. There’s No Apical Migration. 1mm Increase Due To Small Three Wall Defect Inflammation In The Coronal Area. Pseudopockets Deep Three Wall Bony Defect Types Of True Pocket (Periodontal Pocket) Suprabony Pocket (Supracrestal Or Supraalveolar) Cup Bony Defect ❖ Proliferating Pocket Epithelium ❖ Remnant Of Junctional Epithelium Persistent ❖ Base Of Pocket Is Coronal To The Alveolar Crest  ❖ F3 - Through And Through Destruction At Furcation Areas (Total Width Of Furcation Area) ❖ F4 - Same As F3 Except That The Entrance To The Furca Is Clinically Visible Because Of The Presence Of Recession Of The Gingival Margin. Glickman Classification Of Clinical Attachment Level (Cal) Furcation Invasion ❖ Measured From Cej To The Base Of ❖ Grade I: Pocket Formation Into The The Pocket. Flute But Intact Interradicular Bone ❖ Evaluates Amount Of Periodontal ❖ Grade Ii: Loss Of Interradicular Bone Ligament Lost In The Disease And Pocket Formation Of Varying ❖ Identifies Apical Extension Of The Depths Into The Furcation But Not Lesion Completely Through To The Opposite ❖ Measures Severity Of The Tissue Side Of The Tooth Attachment Loss/Connective Tissue ❖ Grade Iii: Through-And-Through Destruction. Lesion ❖ Gingival Recession - Displacement ❖ Grade Iv: Same As Grade Iii With Of The Soft Tissue Margin Apical From Gingival Recession, Rendering The The Cej And Exposure Of The Root Furcation Clinically Visible Surface. Form Of Loss Of Attachment Measured From Cej To The Margin Of Gingiva Suppuration Cal = Ppd + Gr ❖ Presence Of Pus. ❖ Provides Evidence That The Site Is Undergoing A Period Of Exacerbation. ❖ In Combination With Other Parameters, Increases The Positive Predictive Value For Progression Of Furcation Involvement Disease (Increased Chance Of Attachment Loss) ❖ Loss Of Periodontal Support In Furcation Areas Of Multi Rooted Mobility Teeth ❖ Findings From Probing (Nabers ❖ The Degree Of Movement Within The Probe) And Radiographic Analysis Socket Is Measured In Mm. (Radiolucencies At Furcation Areas) ❖ Apply Alternate Forces On Buccal And Lingual Diagnosis Of Furcation Involvement ❖ Physiologic Tooth Mobility ❖ F1 - Loss Of Periodontal Support 0.2mm Tissue Not Exceeding ⅓ Of The Width ❖ Grade 1 Of The Tooth. 0.5-1mm Facial Lingual Tooth ❖ F2 - Loss Of Periodontal Support Movement Tissue (Horizontal) Greater Than 1/3 ❖ Grade 2 But Not Encompassing The Total 1 - 2 Mm Facial Lingual Tooth Width. Movement ❖ Grade 3  More Than 2mm Facial Lingual Tooth Movement New Diagnostic Techniques With Vertical Mobility ❖ Controlled-Face, Standardized Probes Causes (Pressure Sensitive Probes) ❖ Computer Assisted Digital Occlusal Trauma Radiography Loss Of Attachment ❖ Bacteriologic Dna Analysis Periapical Abscess ❖ Immunologic Based Test Treatment: Immunologic Based Test ❖ Depends On The Cause ❖ Immunofluorescent Microscopy Causes: ❖ Assessment Of The Susceptible Host ❖ Occlusal Trauma Using Markers ❖ Normal Bone Level ❖ In Peripheral Blood (Pmn-Leukocyte ❖ Normal Attachment Level Function, Circulating ❖ Excessive Occlusal Force ❖ Antibody Levels, Monocyte Responsiveness To Radiographic Assessment ❖ Lipopolysaccharide) ❖ Provides Information Which Is Not Elisa Test Clinically Detectable ❖ Confirms Clinical Findings ❖ Enzyme-Linked Immunosorbent Assay Test Radiographic Information ❖ Used Primarily To Detect Serum Antibodies To Periodontal ❖ Integrity Of The Lamina Dura ❖ Pathogens, Can Also Be Used To ❖ Amount And Pattern Of Bone Loss Quantify Specific Pathogens ❖ Density Of Supporting Bone ❖ In Subgingival Samples Using Specific ❖ Crown-Root Ratio Monoclonal Antibodies. ❖ Periapical Pathologies ❖ Bana(Benzoyl-Arginine-Naphthylami ❖ Overhangs de) Hydrolysis Test/Perio Scan ❖ Width Of Periodontal Ligament ❖ Test Pressure Of Production Of Space Proteases By P. Ging And B. Forsythus ❖ Calcular Deposits ❖ Anatomical Aberrations Limitation Of Parameters ❖ Only Reveals History Of The Disease ❖ Does Not Show Presence Of Active Disease Nor Predict Its Occurrence ❖ Reveals Only The Consequence Of Past Disease ❖ Inherent Inaccuracies Goals Of Diagnostic Techniques ❖ Identify Disease Initiation And Progression ❖ Monitor Response To Treatment ❖ Identify Persons That Are Susceptible ❖ Differentiate Between Periodontal Diseases  PERIODONTICS 1 DPER 421 | Dr. Sheila May Dee | Lecture | 1st SEMESTER A.Y 2021-2022 WEEK 5: DENTAL CALCULUS & OTHER PREDISPOSING FACTORS PREDISPOSING FACTORS (OF GINGIVAL INFLAMMATION) ✓ Calculus ✓ Faulty restorations ✓ Complications associated with orthodontic therapy ✓ Self-inflicted injuries ✓ Tobacco use PREDISPOSING FACTORS − defined as those factors which retain or hinder the 4 Main Crystal Forms in Supragingival Calculus: removal of plaque and therefore are associated with 1) Hydroxyapatite – sandgrain or rod-like crystals, both the maintenance and severity of gingival detected most frequently in inner layers of old inflammation. calculus − largely local with the most common being the 2) Magnesium whitlockite – hexagonal (cuboidal, formation of dental calculus. rhomboidal) crystals, found in posterior areas, only in small proportions CALCULUS 3) Octacalcium phosphate - platelet-like crystals, − Consists of mineralized bacterial plaque that forms detected most frequently in exterior layers on the surfaces of natural teeth and dental 4) Brushite – more common in mandibular anterior prostheses region, is identified in recent calculus, not older than − Also called “tartar” 2 weeks, and appears to form the basis for supragingival calculus SUBGINGIVAL CALCULUS ▫ Located below the crest of marginal gingiva ▫ Not visible on routine clinical examination ▫ Typically hard and dense ▫ Frequently dark brown or greenish black ▫ Firmly attached to the tooth surface SUPRAGINGIVAL CALCULUS ▫ Located coronal to the gingival margin SUPRAGINGIVAL SUBGINGIVAL CALCULUS ▫ Visible in the oral cavity CALCULUS ▫ Usually creamy white or whitish yellow or brownish in Located coronal to the Located below the crest of color gingival margin marginal gingiva ▫ With claylike consistency Visible in the oral cavity Not visible on routine ▫ Easily detached from the tooth surface, but may clinical examination rapidly recur Usually white or whitish Frequently dark brown or ▫ Color is influenced by contact with substances such yellow or brownish in color greenish black as tobacco and food pigments. With claylike consistency Typically hard and dense Easily detached from the Firmly attached to the tooth tooth surface, but may surface rapidly recur ▫ Supragingival calculus and subgingival calculus generally occur together, but one may be present without the other. ▫ The degree of calculus formation is not only ▫ Microscopic studies demonstrate that deposits of dependent on the amount of bacterial plaque subgingival calculus usually extend nearly to the base present, but also on the secretion of the salivary of periodontal pockets in individuals with chronic glands. periodontitis but do not reach the junctional ▫ Most common locations for development epithelium. o Buccal surfaces of maxillary molars ▫ Appears somewhat more homogeneous since it is o Lingual surfaces of mandibular anterior built up in layers of equally high mineral density. teeth FALSARIO, R. / TORRES, AE. | DMD4Y1-3 | Page 1 of 8  ▫ The predominant mineral is always W, although HA COMPOSITION OF DENTAL CALCULUS has been found. ▫ In the presence of a relatively low plaque ph and a  INORGANIC CONTENT concomitant high o Dental Calculus is composed of 70-90% inorganic ▫ Ca/p ratio in saliva, b is formed and this may later components. develop into ha and w. o Of the inorganic components ▫ When supragingival plaque mineralizes, ocp forms o Approximately, and is gradually changed into ha. - 76% calcium phosphate ▫ In the presence of alkaline and anaerobic conditions - Others (calcium carbonate, magnesium and concomitant phosphate, carbon dioxide, and traces of ▫ Presence of magnesia (or Zn and CO3), large other elements amounts of W are formed in a stable form of - At least 2/3 is crystalline in structure, with 4 mineralization. main crystal forms 1) Hydroxyapatite (HA) = Ca5 (PO4 )3 × OH 2) Magnesium whitlockite (W) = β‐Ca3 (PO4 )2 3) Octacalcium phosphate (OCP) = Ca4H (PO4 )3 × 2H2O 4) Brushite (B) = CaH (PO4 ) × 2H2O Removal of Subgingival Plaque and Calculus  ORGANIC CONTENT − Mechanical removal of subgingival plaque and o Protein-polysaccharide complexes calculus is considered the fundamental cornerstone o Desquamated epithelial cells to the treatment of chronic periodontitis. o Leukocytes − A reduction in gingival inflammation and probing o Various types of microorganisms depths with a gain in clinical attachment can be observed after the removal of subgingival plaque and 1) 1.9 - 9.1% carbohydrates (galactose, glucose, calculus rhamnose, etc.) − When the gingival tissues recede, subgingival 2) 5.9 – 8.2% salivary proteins and most amino acids calculus becomes exposed and is therefore 3) 0.2% lipids (neutral fats, free fatty acids, cholesterol, reclassified as supragingival cholesterol esters and phospholipids) FOUR MODES OF CALCULUS ATTACHMENT TO TOOTH SURFACE 1) Organic pellicle 2) Mechanical locking into surface irregularities 3) Close adaptation to gentle depression or sloping mounts of unaltered cementum 4) Bacterial penetration into cementum surface Radiographic Detection of Calculus o Dental calculus generally adheres tenaciously to − Both supragingival and subgingival calculus may be tooth surfaces. Hence, the removal of subgingival seen on radiographs, but the sensitivity level of calculus may be expected to be rather difficult. detection is inconsistent. o Because the pellicle beneath the bacterial plaque also − The location of calculus does not indicate the bottom calcifies. of the periodontal pocket, because the most apical o Surface irregularities are also penetrated by calculus plaque is not sufficiently calcified to be visible on crystals and, hence, calculus is virtually locked onto radiographs. the tooth. o It may become extremely difficult to remove all calculus deposits without sacrificing some hard tissues of the root. o Although some irregularities may also be encountered on oral implant surfaces, the attachment to commercially pure titanium generally is less intimate than to root surface structures. This in turn means that calculus may be chipped from oral implants without detriment to the implant surface. FALSARIO, R. / TORRES, AE. | DMD4Y1-3 | Page 2 of 8  FORMATION OF DENTAL CALCULUS Local rise in the degree of saturation of calcium and phosphate ions can be due to: ▫ Calcification entails ▫ The binding of calcium ions to the carbohydrate- - A rise in the pH of the saliva causes the precipitation protein complexes of the organic matrix and of calcium phosphate salts by lowering the ▫ The precipitation of crystalline calcium phosphate precipitation constant. salts - Colloidal proteins in saliva bind calcium and phosphate ions and maintain a supersaturated Calculus is mineralized dental plaque solution with respect to calcium phosphate salts. - Phosphatase liberated from dental plaque, ▫ Soft plaque is hardened by the precipitation of desquamated epithelial cells, or bacteria precipitates mineral salts (usually starts between the 1st and 14th calcium phosphate by hydrolyzing organic phosphates days of plaque formation) in saliva, thereby increasing the concentration of free ▫ Calcification occurs within 4 – 8 hours phosphate ions. ▫ Early plaque contains a small amount of inorganic - The progression of mineralization in an incremental material, which increases as the plaque develops into pattern from the inner zones of the bacterial plaque calculus outward may produce concentric rings, called - Saliva is the primary source of mineralization Liesegang rings, that reflect successive phases of for supragingival calculus. mineralization. - Gingival crevicular fluid (inflammatory exudate) furnishes the minerals for subgingival calculus. ETIOLOGIC SIGNIFICANCE OF CALCULUS - Crystals form (a.k.a. Mineralization) initially ▫ Calculus does not contribute directly to gingival in the intercellular (intermicrobial) matrix inflammation, but it provides a fixed nidus for the and on the bacterial surfaces (walls) and continued accumulation of bacterial plaque and its finally within the bacteria. retention in close proximity to the gingiva. - The calcification of supragingival plaque and ▫ Plaque initiates gingival inflammation, which leads to the attached component of subgingival pocket formation, and the pocket in turn provides a plaque begins along the inner surface sheltered area for plaque and bacterial accumulation. adjacent to the tooth structure. The increased flow of gingival crevicular fluid - Separate foci of calcification increase in size associated with gingival inflammation provides the and coalesce to form solid masses of minerals that mineralize the continually accumulating calculus. plaque, resulting in the formation of subgingival - Persons may be classified as heavy, calculus moderate, or slight calculus formers or as ▫ Calculus plays an important role in maintaining and noncalculus formers. accentuating periodontal disease by keeping plaque - The time required to reach the maximal in close contact with the gingival tissue and by level has been reported to be between 10 creating areas where plaque removal is impossible. weeks and 6 months. - The decline from maximal calculus accumulation, which is referred to as the Other Predisposing Factors reversal phenomenon, may be explained by the vulnerability of bulky calculus to  Iatrogenic Factors mechanical wear from food and from the  Margins of Restorations cheeks, lips, and tongue movement. o Retained Cement and Periimplantitis o Contours and Open Contacts o Materials Theories On Calculus Mineralization o Design of Removable Partial Dentures o Restorative Dentistry Procedures 2 CATEGORIES OF THEORETICAL MECHANISMS  Malocclusion 1) Mineral precipitation results from a local rise in the  Periodontal Complications Associated with degree of saturation of calcium and phosphate ions, Orthodontic Therapy o Plaque Retention and Composition which may be brought about by different ways. (See o Gingival Trauma and Alveolar Bone Height next slide.) o Tissue Response to Orthodontic Forces 2) Seeding agents induce small foci of calcification that  Extraction of Impacted Third Molars enlarge and coalesce to form a calcified mass. A.K.A.  Habits and Self-inflicted Injuries the epitactic concept / heterogeneous nucleation. o Trauma Associated with Oral Jewelry o Toothbrush Trauma FALSARIO, R. / TORRES, AE. | DMD4Y1-3 | Page 3 of 8  o Chemical Irritation ▫ Roughness in the subgingival area is considered to  Smokeless Tobacco be a major contributing factor to plaque build up and  Radiation Therapy subsequent gingival inflammation. IATROGENIC FACTORS ▫ Inadequate dental procedures that contribute to the deterioration of the periodontal tissues. ▫ Deficiencies in the quality of dental restorations or prostheses. ▫ Iatrogenic endodontic complications (root perforations, vertical root fractures, and endodontic failures that may necessitate tooth extraction). ▫ Immediate implant placement in conjunction with Sources of Marginal Roughness Include: extraction can contribute to an excessive labial and apical position of the implant yielding to gingival ▫ Grooves and scratches in the surface of acrylic resin, fenestration or dehiscence. porcelain, or gold restorations ▫ Separation of the restoration margin and the luting material from the cervical finish line, thereby MARGINS OF RESTORATIONS exposing the rough surface of the prepared tooth ▫ Dissolution and disintegration of the luting material ▫ Overhanging margins of dental restorations between the preparation and the restoration, thereby contribute to the development of periodontal disease leaving a space. by: ▫ Inadequate marginal fit of the restoration. 1) Changing the ecologic balance of the gingival sulcus to an area that favors the growth of disease-associated organisms PERIIMPLANTITIS (predominantly gram-negative anaerobic species) at the expense of the health- ▫ An inflammatory disease of the tissues around dental associated organisms (predominantly gram- implants resulting in progressive bone loss. positive facultative species) ▫ Periimplantitis is frequently associated with crowns 2) Inhibiting the patient’s access to remove exhibiting retained excessive luting cement. accumulated plaque ▫ A highly significant statistical relationship has been reported between marginal defects and reduced bone height. ▫ The removal of overhangs allows for the more effective control of plaque, thereby resulting in a reduction of gingival inflammation and a small increase in radiographic alveolar bone support. PERIIMPLANT MUCOSITIS ▫ A reversible inflammatory change of the soft tissues around implants without bone loss ▫ The deeper a subgingival crown margin is placed, the higher the likelihood of poorer marginal integrity with accompanying gingival inflammation. ▫ Numerous studies have shown a positive correlation CONTOURS AND OPEN CONTACTS between restoration margins located apical to the marginal gingiva and the presence of gingival  Overcontoured crowns and restorations tend to: inflammation. ▪ Accumulate plaque ▫ Subgingival margins are associated with large ▪ Handicap oral hygiene measures amounts of plaque, more severe gingivitis, deeper ▪ Possibly preventing the self-cleaning pockets, and a change in the composition of the mechanisms of the adjacent cheek, lips, and subgingival microflora that closely resembles the tongue microflora noted in chronic periodontitis. FALSARIO, R. / TORRES, AE. | DMD4Y1-3 | Page 4 of 8 ▪ Restorations that fail to reestablish adequate MATERIALS interproximal embrasure spaces are associated with papillary inflammation. ▫ In general, restorative materials are not in ▪ Undercontoured crowns that lack a protective themselves injurious to periodontal tissues, with the height of contour do not retain as much plaque possible exception of self-curing acrylics. as overcontoured crowns and therefore may not ▫ Although surface textures of restorative materials be as detrimental during mastication as once differ with regard to their capacity to retain plaque, thought. all can be adequately cleaned if they are polished ▪ Overcontoured crowns are more detrimental to and accessible to methods of oral hygiene. periodontal health than undercontoured crowns. ▫ Access for oral hygiene is inhibited with excessive ▪ The contour of the occlusal surface as pontic-to-tissue contact, thereby contributing to established by the marginal ridges and related plaque accumulation that will cause gingival developmental grooves normally serves to inflammation and possibly the formation of deflect food away from the interproximal pseudopockets spaces. ▪ The optimal cervico-occlusal location for a DESIGN OF REMOVABLE PARTIAL DENTURES posterior contact is at the longest mesiodistal diameter of the tooth, which is generally just ▫ Partial dentures favor the accumulation of plaque, apical to the crest of the marginal ridge. particularly if they cover the gingival tissue. ▪ Food impaction - the forceful wedging of food ▫ The presence of removable partial dentures induces into the periodontium by occlusal forces. not only quantitative changes in dental plaque but ▪ The integrity and location of the proximal also qualitative changes, thereby promoting the contacts along with the contour of the marginal emergence of spirochetal microorganisms. ridges and developmental grooves typically prevent interproximal food impaction. ▪ Plunger cusps- cusps that tend to forcibly wedge RESTORATIVE DENTISTRY PROCEDURES food into interproximal embrasures ▪ As teeth wear down, their originally convex ▫ The use of rubber dam clamps, matrix bands, and proximal surfaces become flattened, and the burs in such a manner as to lacerate the gingiva wedging effect of the opposing cusp is results in varying degrees of mechanical trauma and exaggerated. inflammation. ▪ The interproximal plunger cusp effect may also ▫ The forceful packing of a gingival retraction cord into be observed when missing teeth are not the sulcus to prepare the subgingival margins of a replaced and the relationship between the tooth or for the purpose of obtaining an impression proximal contacts of adjacent teeth is altered. may mechanically injure the periodontium and leave ▪ An intact proximal contact precludes (to prevent behind impacted debris that is capable of causing a something or make it impossible) the forceful foreign body reaction. wedging of food into the interproximal embrasure space. MALOCCCLUSION ▪ A light or open contact is conducive to impaction ▫ The irregular alignment of teeth as found in cases of ▪ Posterior teeth with open contact and food malocclusion may facilitate plaque accumulation and impaction exhibit greater probing depth and make plaque control more difficult. clinical attachment loss than contralateral control ▫ Several authors have found a positive correlation sites without food impaction. between crowding and periodontal disease, whereas ▪ Excessive anterior overbite is a common cause of other investigators did not find such a correlation. food impaction on the lingual surfaces of the ▫ Roots of teeth that are prominent in the arch maxillary anterior teeth and the facial surfac