STENCILDENT

  PERIODONTAL EXAMINATION OF  TEETH,IMPLANTS,PERIODONTIUM AND  PERIODONTAL POCKET  1)EXAMINATION OF TEETH AND IMPLANTS: A)TOOTH MOBILITY : All teeth have a slight degree of physiologic mobility which varies for : Different teeth Time  During the morning it will be greatest ,slight extrusion of tooth whereas ,during sleep it will be limited as there is not much  Occlusal contact these 24 hour variants are seen in those who  Have occlusal habits  such as : Bruxism Clenching LOCAL CAUSES: Periapical pathology Tooth morphology Implant mobility SYSTEMIC CAUSES : Age  Sex(females more predilection) Oral contraceptive Other Cause : Loss of tooth support Trauma from occlusion STAGES : 1)INITIAL /INTRASOCKET STAGE : Tooth moves within the confine of periodontal ligament  Associated with : Viscoelastic distortion Redistribution of periodontal fluid  2)SECONDARY STAGE: Occur gradually  Increase in horizontal force results in elastic deformation of alveolar bone  GRADING: According to ease and ext

  DERMATOPHYTE  Infection caused by fungi is known as mycosis  Types: Superficial Subcutaneous Systemic SUPERFICIAL : Affect surface  Types : Superficial infection  Example -Tinea nigra,Piedra Cutaneous :Dermatophyte  DERMATOPHYTE : Superficial mycoses that affect only superficial keratinised tissue (hair,skin,nail) Break down and utilise keratin Infection caused it DERMATOPHYTOSES,tinea or ringworm GENUS ORDER  TRICHOPHYTON-Hair,skin,nail MICROSPORUM-hair,skin EPIDERMOPHYTON-skin,nail CLINICAL TYPES: Named based on site of involvement  Scalp-tinea capitis Groin-tinea cruris No hair involvement -tinea corporis Foot-tinea pedis or athlete's foot Beard -tinea barbae or barber's itch Chronic type with hair involvement is called FAVUS  FAVUS is followed by alopecia and scaring Its of two types ectothrix,endothrix Atherospore sheath over the hair shaft-ectothrix Atherospore within hair shaft -endothrix LAB DIAGNOSIS : SPECIMEN : Hair scraping,skin scraping ,nail DIRECT MICROSCOPY  1

  MALIGNANT SKIN TUMORS  1)INTRODUCTION: Skin is outermost coat of human body  Skin act as a protective cover against various insulting agents such as ultraviolet radiation of sunlight 3 malignant skin tumour : Squamous cell carcinoma Basal cell carcinoma Malignant melanoma 2)PRESENTATION : A)SQUAMOUS CELL CARCINOMA: Carcinoma of cell of epidermis ,starts from prickle cell layer and migrate towards the outer surface. May occur in pre-existing lesion of skin: Marjolin ulcer Venous ulcer Leukoplakia Site: Junction of skin and mucous membrane eg(lip,eyelid) It is also seen in mucous membrane lined by stratified squamous epithelium (eg)tongue,mouth Predisposing factors: Scar,ulcer Exposure to sunlight or irradiation Bowen's disease Types: Proliferative Ulcerative  B)BASAL CELL CARCINOMA (RODENT ULCER) Common malignant skin tumors  Slow growing neoplasm Location: Majority of lesion found on face above a line from lobule of ear to angle of mouth Common Site : Eyelid Bridge of the nose Ar

 ELASTOMERIC IMPRESSION MATERIAL  PART 2 ADDITION SILICONE: AVAILABLE AS : 1)LIGHT 2)MEDIUM 3)HEAVY 4)PUTTY VISCOSITIES: PASTE: 2 equal size collapsible tube Cartridge:use with gun Putty jar Base paste : 1)Poly methyl hydrogen siloxane 2)Other siloxane pre-polymer 3)Hybrid silicone 4)Filler CATALYST PASTE : 1)Polydimethylsiloxane 2)Platinum salt activator 3)Palladium 4)Retarder  5)Filler  SETTING REACTION: Addition reaction No by product  Cross linkage between vinyl terminated silicone with silane terminated silicon  2nd reaction: Moisture +residual hydride Hydrogen gas is formed  Addition noble metal (platinum or palladium )to component that act as hydrogen absorber HYDROPHILIC SILICONE : Addition of surfactant  Advantage : Decreases air bubble in gypsum , Better wetting of soft tissue Disadvantage: Difficult to electroplate  Character: No by product  More dimensional stable Addition of surfactant turn to hydrophilic  ADVANTAGE: Clean,pleasant easily seen margin elasticity pour repeat

  ELASTOMERIC IMPRESSION MATERIALS  - PART 1  ELASTOMERIC :Rubber -like polymers that shows as elastic behaviour at the time of load application  These polymer molecules have weak interaction in between (Van der wall forces) They have tied together in 3D network  4 ELASTOMERIC IMPRESSION MATERIALS: 1)POLYSULFIDE 2)CONDENSATION -POLYMERIZATION SILICONE 3)ADDITION-POLYMERISATION SILICONE 4)POLYETHER   1)POLYSULPHIDE: 1st material introduced also known as mercaptan/thiokal Collapsible tubes : Base: White colour Catalyst: Brown,grey  VISCOSITIES: Heavy Medium Putty BASE : Low molecular weight polysulphide Filler (Titanium dioxide) plasticizer(Dibutyl phthalate) Accelerator(0.5% Sulphuric acid ) CATALYST: Lead oxide Filler (Titanium dioxide) Plasticizer(Dibutyl phthalate) Retarder(Oleic acid and Stearic acid) Condensation polymerisation: Mercaptan+lead dioxide  = polysulphide +water CHARACTER: Water by product +polymerisation shrinkage =dimensional changes Water could cause air bubble in st

  HUMAN IMMUNODEFICIENCY VIRUS  HUMAN -It can live only in human IMMUNODEFICIENCY -Damages the immune system of people it infects  VIRUS -Retrovirus (RNA) MORPHOLOGY: Spherical enveloped virus diameter :90-120 nm composed of 2 copies of positive single stranded RNA enclosed by conical capsid composed of viral protein p24 RNA genome consist of 9 gene  3 genes :gag,pol,env contain information needed to make the structural protein for new virus particle CAPSID : There are 3 enzyme required for HIV replication  REVERSE TRANSCRIPTASE INTEGRASE PROTEASE MATRIX: Composed of viral protein p17 surrounds the capsid  ensuring integrity of virion particle surrounded by phospholipid spikes 2 units -gp41 and gp120  PATHOGENESIS: 1)HIV attachment to host CD4 cell 2)Reverse transcriptase makes DNA from the virus RNA 3)Integration into host cells nucleus 4)Reproduction of viral components 5)Assembly of new HIV viruses 6)Virus release by budding (enzyme -protease) 7)Viral replication ,fusion,integrase 8

  DENTAL IMPLANT  A dental implant is a material /device in and or on oral tissue to support an oral prosthesis PARTS OF AN IMPLANT  : ABUTMENT- Support crown,provide retention IMPLANT BODY-Placed in bone HEALING SCREW-Prevent growth of tissue at edge of implant HEALING CAP-Maintenance of tissue  CHARACTERISTICS OF IMPLANT : 1)Sterile 2)Highly biocompatible 3)Should have primary stability 4)Should have adequate loading at time of healing 5)It should have surface configuration 6)It should consist of 2 parts :  a)Favour bioadhesion b)Non-adhesion  CLASSIFICATION: A)MATERIAL USED : 1)METAL AND ALLOY :Titanium and its alloy ,stainless steel 2)CERAMIC:Made of carbon with stainless steel 3)POLYMER AND COMPOSITE:Polymethylmethacrylate,polytetrafluorethylene B)BIOLOGICAL RESPONSE: 1)BIOTOLERANT : Gold Cobalt-chromium Not easily rejected when implanted in living tissue 2)BIOINERT: Titanium Allow close opposition of bone 3)BIOACTIVE: Bioglass Material that allow formation of bone onto their surf