Cariology 1 - Lectures 1-5 PDF

Cariology 1 - Lectures 1-5 Lecture 1 - Intro to Cario, PPE I. PPE Protocol A. Donning - Gown, Mask, Goggles/Loupes, Face Shield, Gloves B. Doffing - Gloves, Face Shield, Goggles/Loupes, Mask, Gown Lecture 2 - Burs and Handpieces I. Bur Anatomy A. Head, N...

Cariology 1 - Lectures 1-5 Lecture 1 - Intro to Cario, PPE I. PPE Protocol A. Donning - Gown, Mask, Goggles/Loupes, Face Shield, Gloves B. Doffing - Gloves, Face Shield, Goggles/Loupes, Mask, Gown Lecture 2 - Burs and Handpieces I. Bur Anatomy A. Head, Neck, Shank B. Materials - Carbide, Diamond, Steel, Ceramic C. Grit - 1. Diamond - ^ Grit, v microns 2. Carbide - ^ Grit, ^ # of Blades II. Handpiece Primer Handpiece Bur Width Gear Ratio Speed Range Torque Friction Grip (FG) 1.6 mm 1:5 500 - 200,000 0.7 Ncm Right-Angle Latch (RA) 2.35 mm 1:1 60 - 40,000 3.5 Ncm Lecture 3 - Rubber Dam shit that we’ve done like 50 billion times just figure it out Lecture 4 - Tooth Nomenclature I. Jaw A. Maxilla on top, mandible on bottom II. Dentition Arch Total # Incisors Canines Premolars Molars Universal Numbering Primary/Deciduous 20 8 4 0 8 Letters from UR Permanent 32 8 4 8 12 #’s from UR III. Succedaneous Teeth - Permanent teeth that replace deciduous teeth  A. Permanent Incisors, Canines, and Premolars (#4-13, #20-29) IV. Non-succedaneous Teeth A. Permanent Molars (#1-3, #14-19, #30-32) V. Diphyodont - having two sets of teeth throughout a lifetime VI. Natural Tooth Curvatures A. Curve of Spee/Anteroposterior Curve - natural mandibular rounding of occlusal surfaces B. Curve of Wilson/Mesiolateral Curve - natural mandibular rounding of teeth lingually VII. Tooth Numbering Systems A. Universal B. FDI  C. Sextants - organizes anterior/posterior teeth D. Palmer Notation VIII. Tooth Structures/Anatomy A. Diastema - the gap between occlusal surfaces of teeth  B. Embrasure - triangular gaps of spacing between teeth faciolingually 1. Incisal/Occlusal Embrasure and Cervical Embrasure 2. 3. Buccalabial Embrasure and Lingual-palatal Embrasure 4. 6) Resin Composites Composition of Resin Composites ○ Matrix (Organic) - glue, all ends with dimethyl acrylate BIS-GMA* thickest, circled is acryloyl group long molecule with rings -> makes it polar -> makes material thicker, not fluid, thick fillings UDMA: flowy material, add to BIS-GMA to make flowy TEGDMA: flowy material ○ Filler Particles (Inorganic) - reinforcement Inorganic particles - ie quartz, lithium aluminum silicate, zirconia, glasses (barium, strontium, zinc, ytterbium)  Reduces polymerization shrinkage, water absorption, and coefficient of thermal expansion Size decrease + percentage of FP in composite increase over the years CURRENT nano-hybrid (0.002-0.075 um @ 72-78% comp. weight) Filtek Supreme XT (what we use) 78.5% vol. filler particle, good polishability, high strength, light- cured ○ Coupling Agents (Silanes) - connects matrix and filler particles Silanes - has both silane group bonds to glasses (FP) and acryloyl group (Matrix) ○ Optical Modifiers (Inorganic) - pigments (inorganic oxides) to match shade Fluorescence - LONGER WAVELENGTH ABSORPTION/REFLECTION Opalescence - SHORTER WAVELENGTH SCATTERING Opacity - measure of impenetrability to visible light, Enamel > Dentin Halo - translucency at incisal edge Elderly patients have less enamel so teeth appear darker Color Matching Tools - Shade Guide/Spectrophotometer ○ Initiators/Accelerators - speeds up curing process Chemical - Init. Benzoyl Peroxide, Accel. Organic Amine Light - Init. Diketone, Accel. Organic Amine Camphorquinone (CQ) - 468 nm, bluelight Lucirin TPO - 370 nm, UV Phenylpropanedione - 370 nm, UV Dual Cured - uses both initiators Valolight Light Cure - 395-415 nm and 440-480 nm Polymerization - Acryloyl groups’ (DB’s in matrix monomers are reduced and fused with the help of light/heat/chemicals ○ Three types Linear Branched Crosslinked ○ 3 Steps Initiation - benzoyl peroxide (BPO) initiator breaks its’ O-O bond to produce O free radicals which goes onto reduces acryloyl group Propagation - reduced DB on acryloyl group continues to reduce further acryloyl groups  Chain Transfer - sometimes reduced acryloyl chain 1 can regain its double bond by reducing another acryloyl chain 2, but acryloyl chain is now reduced and goes onto propagate reaction Termination Scenario 1) 2 reduced acryloyl chains reduce each other and form a single bond Scenario 2) 2 reduced acryloyl chains reduce each other and form one chain with DB and one separate chain with SB ○ Polymerization Inhibitors - Conversion Rate - 50-70%, rigidity increase with propagation Eugenol - temp fillings/cements Peroxide - bleaching Oxygen Inhibiting Layer (OIL) - Oxygen in air oxidizes superficial acryloyl groups and inhibits chain propagation Facilitates polymerization of iterative composite layers 4-84 mm thick Reduces mechanical/physical properties, prone to staining Remove OIL by polishing at end of composite layering ○ Polymerization Shrinkage - ~2-10% as monomers get closer together C-Factor - bonded surfaces/unbonded surfaces ^ C-Factor = ^ shrinkage stress Class I + V have greatest stress ^ monomer size = v shrinkage Effects - debonding, gaps, microleakage, secondary caries, enamel microcracks Can Fix By - smaller fillers, larger monomers, soft-start curing lights, layer composites in 2mm increments to lower C-Factor 7) Cavity Classifications and Principles of Cavity Preparation Caries Classifications ○ Class I – O All pit and fissure preps ○ Class II - M and/or D + O optional on post. Proximal surfaces of posterior teeth ○ Class III - M/D/L/F no I on ant. Proximal surfaces of anterior teeth not including incisal edge ○ Class IV - M/D/L/F + I on ant. Proximal surfaces of anterior teeth including incisal edge ○ Class V - gingival third of facial/lingual surfaces Abfraction - cervical/wedge-shaped defects due to grinding Abrasion - friction w/ external objects Erosion - chemico-mechanical action ○ Class VI - incisal (ant.) and or occlusal (post.) cusp tips Point Angles - points of junction of 3 or more prep. Walls Objectives of Tooth prep ○ Preserve healthy tooth structure ○ Remove diseased structure ○ Provide restorative form ○ Esthetic reimplementation Steps for Preparation: 1) Initial Depth + Outline Form ○ 0.2 mm beyond DEJ/0.5-0.8 mm into root suraces ○ Visualize shape of prep, 90 deg of prep 2) Primary Resistance Form ○ Maintain 90 deg. To axis of preparation ○ Enhance stability of a restoration along an axis other than path of placement ○ ie round internal angles to resist cracking, remove unsupported tooth structure (unsupported enamel rods), pulpal/gingival floors perpendicular to occlusal forces 3) Primary Retention Form ○ Prevents dislodgement of a crown in vertical direction/ path of placement ○ ie undercuts, grooves, slots or pins ○ Secondary retention forms - grooves to prev comp from falling out or parapulpal pins, not common anymore 4) Convenience Form ○ Features to facilitate procedure/make the area more accessible  5) Removal of defective restorative materials/soft dentin 6) Pulp protection 7) External Wall Finishing 8) Final Procedures - debridement/inspection 8) Magnification Resolution - smallest distance between two points to perceive them separately ○ Unaided eye resolution = 200 um Ergonomics - position 1-4, 1 = 0 deg declination, each position increases angle by 15 deg Declination Angle - angle that eyes are inclined downwards toward work Head Angle - head tilt angle Viewing Angle - declination angle + head angle Loupes - ○ 1) Simple Lens - 1 convex lens prone to distortion, makes objects bigger Binocular simple can cause spheric operation and chromatic operation distortion ○ 2) Compound/ Galilean Lens - 1 convex (converging) + 1 concave (diverging) lens No distortion with dual lenses limited magnification due to length ^ length = ^ magnification = v image lighting ○ 3) Prismatic/ Kepler Lens - multiple convex lenses Schmidt-Pechan Prism - flips image back to correct orientation ^ magnification = v field of view = v field of depth CAN BE ANGLED - so fixes declination angle ○ 1) Through-the-lens (TTL) Loupes - Custom-made, closest to eyes, prescription possible ○ 2) Flip up Loupes Off-the-shelf, further, prescription possible, adjustable, can be shared ○ Frames - Metal Frame Sports Frame Head Gear - ADJUSTABLE, uncomfy ○ Add ons - light or light+battery, orange filter for composite preps Microscopes ○ Advantages - less eye convergence strain, no declination angle ○ Tube head reorients light  ○ End Magnification = Tube focal distance/lens focal distance * mag. Changer factor * eyepiece factor 9) Posterior Composite Restorations Prim. Caries Indications - (when we can restore posterior teeth using direct composite resin) ○ Primary carious lesions Secon. Caries Indications - (when we can restore posterior teeth using direct composite resin) ○ Replacement of composites and amalgam restorations Contraindications – when we cannot restore ○ Large restorations - use indirect ○ Inadequate Isolation ○ Heavy Occlusal Stress ○ High Caries Risk ○ (LIHH) – Live In His House Composite Advantages ○ Esthetics, conservative, less complex, decreased microleakage, increase strength of remaining tooth structure Composite Disadvantages ○ Polymerization shrinkage ○ Lower fracture toughness vs. indirect ○ More technique sensitive ○ Possible greater occlusal wear ○ BPA could be used (similar to estrogen) Protocol ○ 1) Anesthesia ○ 2) Pre-op. Occlusion - articulation paper ○ 3) Prophylaxis - clean w/ pumice ○ 4) Color Matching - shade match, do before RD placement ○ 5) Operative Field Isolation - RD ○ 6) Cavity Preparation - drilling ○ 7) Adhesive System - 35% phosphoric acid etchant, bond 1) Etch + Rinse (total etch)- etch > dessicate > primer > dessicate > bond > LC 2) Etch + Dry (self etch) - primer/etch hybrid > dessicate > bond > LC 3) Selective Etch - differentiates in dentin/enamel NOTE* single step bond/etch SUCKS ○ 8) Composite Placement - refer to chapter 7  ○ 9) Final Light Cure ○ 10) Check Occlusion - articulation paper ○ Finish and Polish 10) Temporary Direct Restorations 1) Zinc-Oxide Eugenol (reinforced w/ PMMA) ○ Curing - Self-cured (liquid + powder) ○ Base protective restoration ○ Inhibits polyermization!!! ○ Can soothe teeth but increased internal tooth inflammation (NOT USED) 2) Calcium Sulfate (gypsum) - (ie CAVIT) ○ Curing - Hygroscopic setting - hardens with water ○ Class I or C II ○ High expansion ○ LONG 2-hour setting time ○ Procedure - scoop to mixing pad > shape w/ instrument or bite > moisten w/ wet cotton > can use slow carbide bur/cavitron to remove 3) Light-cured Resin (ie Telio Onlay 20s LC) ○ Curing - Light-cured ○ Contains trace fluoride ○ For temping inlays/ onlays/ implant screw healing 4) Glass Ionomer Cements (Class Vs) ○ a) Cavity Liner - inner coating to cover prep. walls, seals tubules and pulp Helpful for amalgam which is thermoconductive ○ b) Base/restorative Foundation - blocks undercuts, thermal/chemical barrier, saves on cost of expensive indirect rest. ○ c) Build Up - provides coronal anatomy to endo-treated tooth ○ Acid-Base Reaction - Calcium-Aluminosilicate w/ Polyacrylic Acid, chemically bonds to tooth as opposed to composites which adhere Tartaric Acid as accelerator, Silver to mimic amalgam Liquid Acid attacks Glass Base > glass releases Ca/Al cations and F > cations cross-link to form salt matrix w/ polyacrylic acid note - fluoride released can form fluoroapatite/fluorohydroxyapatite but diminishes in effectiveness in 2 weeks, can replenish with F-varnish ^ F release v Mechanical Properties GIC > RMGIC > Compomers > Composites ○ Sensitive to moisture, can apply protective varnish ○ Fuji IX -  Mixing Time - 10s Working Time - 2 min/ 120 s Setting Time - 6 min/ 360 s Powder to Liquid Ratio - 0.4/0.11 5) Resin Modified Glass Ionomer Cements (ie Fuji 2LC and Fuji Triage) ○ Adds Methacrylate Polyacid matrix + amphipathic HEMA ○ A/B rxn AND Polymerization for increased stability ○ HEMA has alcohol group for salt matrix and DB for composite matrix reduction ○ 1) Fuji 2LC - dual-cured, resin-modified, protective for C III and C V Mixing Time - 10 s Working TIme - 3 min 15 s/ 195 s Light Curing Time - 20 s Depth of Cure - 1.8 mm Powder to Liquid Ratio - 0.33/0.1 ○ 2) Fuji Triage - pink Mixing Time - 10 s Working Time - 1 min 40 s/100s Setting Time - 2 min 30 s/150 s Powder to Liquid Ratio - 0.3/0.15 ○ Protocol 1) Apply Cleaners - cavity conditioner + 20% polyacrylic acid and rinse 2) Activate 3) Mix - 7 s, not full 10 s to have more time 4) Dispense w/ gun FILTEK SUPREME ULTRA NANOFILLERS TELIO ONLAY - LC Lecture 11 - Enamel and Dentin 3 Stages of Tooth Development ○ Bud - (6th week prenatal) Formation of buds onto the dental lamina Ectomesenchyme Cells - Ectodermal cells from epithelium proliferate into underlying mesenchyme ○ Cap - (9th or 10th week prenatal) Bud enlarges into a cap shape, forming enamel organ, dental papilla, and dental follicle ○ Bell - (11th or 12th week prenatal) The tooth’s crown develops (ergo bell shape) and develops hard tissue  Separates from the dental lamina Enamel Composition - 88% inorganic, 2% organic, 10% water Inorganic - Amelogenesis ○ Ameloblast - cell elongates, nuclei moves to top of cell, distal parts differentiate into wedge-shapes Secretory Stage - ameloblasts secrete hydroxyapatite crystals from the Tomes Processes which are positioned at distal end of the ameloblast to form enamel rods Maturation Stage - more minerals secreted (Calcium and Phosphate) to harden the enamel rods ○ Enamel Rods - HA Crystals - 25 nm thick, 100 nm wide, 500-100 nm long, arranged into 5 um rods, wrapped in 1 um protein sheath Arranged perpendicular to DEJ, parallel to each other Crystals near edge of the rod can tilt (15-45 deg) to have more force dispersion 3 main enamel structures - sheath, rod, and inter-rods (connecting structures) Organic - ○ Proteins - amelogenin, ameloblastin, enamelin, tuftlelin Regulates enamel growth, promotion, termination, and organization ○ Enzymes - metalloproteinases (MMP), proteinase, phosphatase Regulates enamel/dentin and affects bonding Enamel Thickness Across Tooth - gets thiccer as you go up tooth from CEJ ○ Gingival 1/3 - 0.3 - 0.4 mm ○ Middle 1/3 - 0.5 - 0.6 mm ○ Incisal 1/3 - 0.8 - 1.0 mm Enamel Structures (SCHOITL) ○ Striae of Retzius/ Retzius Line Incremental growth lines, suggests successive deposition of enamel layers Perikymata - retzius lines on superficial teeth surface, gives teeth texture ○ Enamel Cross Striations Demarcate enamel deposition by ameloblasts DAILY (4 um/ day, ranges from 2.5-6.5 um)  ○ Hunter-Schreger Bands (HSBs) Set of 10> rods, related to synchronous decussation of enamel rods Reflects light differently Structural adaptation that increases enamel strength (found prominently in occlusal surfaces like posterior teeth cusps) ○ Outer Enamel Rigid, parallel rods arranged perpendicularly to DEJ Higher rigidity The outermost layer contains aprismatic enamel Aprismatic enamel: no pronounced or no rods at all. Hardest layer of enamel ○ Inner Enamel Closer to DEJ, more rod decussation (crossing over) Higher elasticity (aka lower modulus of elasticity) (Dissipates force) Increased organic content Contains enamel tufts ○ Enamel Tufts Brush-like structures extending directly from DEJ Hypomineralized and protein-rich to provide cushioning ○ Enamel Lamellae  Fissure-like projections further from DEJ Includes proteins, proteoglycans, and lipids Enamel Disorders - ○ Dental Fluorosis Increased enamel porosity along Retzius Lines Hypomineralized lesions through enamel caused by Fluoride ions reducing HA producing excess fluorapatite ○ Amelogenesis Imperfecta Genetic Hypocalcification - defect in the secretion stage Hypomaturation - defection in the maturation stage Hypoplastic - defect in amount of enamel DEJ Scallop-apperance: 30 um incisors and 43 um molars, convexity directed toward dentin ○ Prevents enamel cracks from permeating into dentin ○ More durable along enamel side Dentin Composition - 50% inorganic, 30% organic, 20% water Organic ○ 90% Type I Collagen - trace Type 3 and 4 ○ 10% Non-collagenous components: Proteins: Amelogenin, Osteonectin, Osteocalcin Enzymes: MMPs, tissue inhibitors of MMPS (TIMPS), acid/alkaline phosphates Lipids Growth Factors Inorganic ○ Crystallites: 2-5 nm thickness, 60 nm length, needle-like Dentin Structures ○ Dentinal Tubules - holes from DEJ to pulp Water, fluids, odontoplastic processes More tubules closer to pulp in deep dentin vs superficial dentin (45,000/mm2 vs 20,000/mm2) ○ Peritubular Dentin - highly-calcified and surrounds/protects tubules 96% HA crystallites (25-30 nm) 4% organic content Hardness: 2.23-2.5 GPa resistance force ○ Intertubular Dentin - space between tubules  88% HA crystallites (2-5 um and 60 nm long) 12% organic content: collagen-rich and proteins Hardness: ~0.5 GPa near DEJ to ~0.16 GPa near pulp Types of Dentin ○ Primary - initial dentin formed near DEJ after eruption ○ Secondary - dentin formed between initial tooth formation and remaining life of tooth ○ Tertiary - reactive/reparative dentin formation Reactionary Dentin - odontoblast/Hoehl’s cell calcification response to anything (caries, prep, abrasion, erosion, attrition, toxicity etc...) Reparative Dentin - formed in response to pulp exposure Dentin Bridge - barrier formed to protect exposed pulp ○ Sclerotic Dentin - formed due to occlusion and hypermineralization of superficial tubules Example: non-carious cervical lesions (NCCLs) near CEJ Air pushes odontoblasts down exposed tubules, increases calcification Brannstrom’s Hydrodynamic Theory - air/temp/pressure moves odontoblasts in tubules, triggering main response in pulp Dentin Disorders - ○ Dentinogenesis Imperfecta - genetic mutation of DSPP gene, producing soft dentin (discolored), lack of dentin tubules and lack of cushioning collagen Type I - COL1A1/COL1A2 causing osteogenesis imperfecta (all bones), brittleness to all bones Type II - most common, associated with hearing loss Type III - common in South Maryland and Ashkenazi Jews Lecture 12 - Caries Scale: perm. 2.3 billion, deci. 0.5 billion Prevalence: proportion of the population Incidence: new cases Caries - transmissible, infectious oral disease caused by interaction between cariogenic oral flora (biofilm) with fermentable carb sources on tooth over time ○ Vertical Transmission - bacteria from higher generation, eg. mom -> baby ○ Horizontal Transmission - same generation, eg. sibling -> sibling ○ Protective Factors - salivary flow, proteins, antibacterials, fluoride, ions (calcium/phosphate), protective diet (non-cariogenic sweeteners like xylitol) ○ Pathological Factors - acidogenic bacteria, fermentable carb. ingestion, xerostomia  Cariogenic Challenge - oral flora converts mono/di saccharides into pyruvic acid (glycolysis) and then lactic acid (lactic acid fermentation)... or propionic/acetic acid ○ Stephan Curve - acid drops pH (< 5.5 pH), demineralizes enamel, saliva/enzymes neutralize pH ○ note higher threshold pH for dentin because it’s more sensitive Microbiology ○ A) White Spot Lesions/ Initial Caries - like an initial scar, strep. mutans ○ B) Dentinal Caries/Tubule Infection - more lactobacillus ○ C) Root Caries - actinomyces attracted to roots specifically Caries Factors: Time and Teeth (external) and Bacteria and Diet (internal) ○ Teeth - most prevalent: pits/fissures > root/cervical > interproximal Higher prevalence in restorations/ortho appliances as they introduce man-made overhangs for bacterial growth ○ Bacteria/Time - 1) Pellicle (0-24 hrs) - thin glycoprotein layer, electrostatically sticks to enamel, acts as a primer for bacterial growth recruiting more bacteria 2) Biofilm Formation (4-24 hrs) - co-adhesion of bacteria, microcolonies 3) Microbial Succession (1-7 days) - bacterial diversification  4) Climax (>1 week) - mature biofilm, plaque build-up Resident Oral Flora - Gram+/Gram- bacteria, yeasts, other microbes Symbiotic Relationship - takes space from bad bacteria, produces peroxide, kills bad bacteria, secretes inhibitory factors Ecological Plaque Hypothesis - current theory, many carious bacteria but also depends on environment ○ Diet Mono/di saccharides are hardest to break down with saliva Amylase and other salivary enzymes can break down complex sugars Sugar Alcohols - alt. Sweeteners with anti-cariogenic properties, eg. xylitol, lactitol, isomalt Lesion Progression - ○ Sub-surface lesion under surface layer ○ H+ in and Calcium/Phosphate out ○ Pore volume increases up to 30%, and microorganisms and substrate permeate ○ Light scattering causes white spot ○ ○ 1) White Spot - acid travels to dentin tubules, forming sclerotic dentin ○ 2) White/Brown Spot - demineralized dentin and tubules near DEJ and formation of tertiary (reactionary) dentin near deep dentin ○ 3) Micro-Cavitation - enamel breaks down, lesion accelerates ○ 4) Cavitation - inorganic tissues disintegrate forming zone of destruction ○ Removed dentin will be wet/leathery Lecture 13 - Dental Adhesion Enamel and Dentin require modifications to bond adhesive monomers (Enamel) Biofilm - oral flora, plaque, debris (Dentin) Smear Layer - created by handpiece on dentin ○ Composition - amorphous (1-5 um), residual debris/oil from bur ○ Obstructs tubules by 86% ○ Carbide Bur: heat (2um layer) < Diamond: abrasive force (5 um layer) ○ Can be removed with 1.5-3 pH smear layer acid remover Etch - (35% Phosphoric Acid) creates more surface area, decalcifies enamel ○ Helps with micromechanical retention, clears smear layer, helps adhesive bond to enamel/dentin (hydrophilic) and resin composite (hydrophobic) Primer - diffuses etchant across the tooth ○ Contact Angle - lower viscosity, hydrophilic, more surface spread upon ○ Bifunctional Monomers (BFM) - h.philic for enamel/dentin, h.phobic for resin eg. HEMA, Bis-GMA, 10-MDP, TEGDMA, GDMA, UDMA ○ Solvent - removes water and makes space for BFM, lowers viscosity of bond to allow for greater permeation eg. water, ethanol, acetone Bond - adhesive ○ Smaller BFMs - eg. Bis-GMA, HEMA, TEGDMA ○ Photoinitiators - eg. CQ ○ Fillers - inorganic, increases strength eg. silicon, aluminum, silicon dioxide (2-5 nm) Mechanisms of Adhesion ○ Micromechanical - STRONGER Penetration, permeation, and polymerization of resin monomers ○ Chemical - Chem. bond to HA via ionic bond/salt formation Chem. bond to collagen via cross-linking covalent bonds Classification of Adhesive Systems ○ 1) Etch and Rinse 1a) Three-Step: etch, primer, bond Etch - 35-37.5% phosphoric acid Primer - highly hydrophilic Bonding Resin  1b) Two-Step: etch, primer+bond Higher concentration of solvents (