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Parodoniul
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Histoarhitectonia proceselor alveolare
Histoarhitectonia ligamentului parodontal
Histoarhitectonia cementului Histoarhitectoniajonciunii dentogingivale
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Histoarhitectonia proceselor alveolare
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Generaliti
Arii/teritorii din maxilare/mandibule care formeaz/conin alveolele dentare, ncare sunt localizai i ancorai dinii (prin ataarea fibrelor ligamentuluiparodontal)se formeaz n paralel cu elongarea radicular, ca rezultat al acestui proces i alerupiei dentarentre osul maxilar/mandibular i procesele alveolare nu se poate trasa o limit de
demarcaiematurarea proceselor alveolare concomitent cu stabilirea dintelui n ocluziefuncionalntre procesele alveolare idiniexist o strnsinterdependen: dac dintele sepierde, procesele alveolare involueazi disparosul alveolar cel mai instabil component parodontal cu activitate metabolic
extrem de ridicatialternana proceselor de resorbiei formare
Procesele alveolare = os alveolar varietate de esut conjunctiv format dintr-o matriceextracelularicelule proprii matricea extracelular include o component organic i o component
anorganic
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Structura histologica proceselor alveolare
COMPONENTAORGANICalctuit din proteine fibroase (colagen tip I 90% i colagen tip V n cantitimici) plus alte macromolecule (glicozaminoglicani, proteoglicani,glicoproteine de adeziune)
Fibrele de colagen tip Idiferite de colagenul tip I din alte esuturi conjunctive permite legturamoleculelor prin puni de hidrogen rezistencrescutorganizarea primar, n reeanlocuit n osul matur printr-o dispunereordonat,spiralat, cu un grad de rsucire de la o lamel la altaGlicozaminoglicanii
lanuri polizaharidice lungi nesulfataiacidul hialuronic sulfatai:condroitinsulfat, keratansulfat formnd proteoglicani
Moleculele glicoproteice de adeziuneosteocalcina, osteonectina, osteopontina, trombospondina i sialoproteina
osoas
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COMPONENTA ANORGANIC
67% din masa uscat a matricei extracelulare
format n principal din cristale dehidroxiapatit
CELULELE ESUTULUI OSOS
tipuri celulare: celula osteoprogen, celula bordant,
osteoblastul, osteocitul, osteoclastul
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Organizare spaial
Trei elemente (os fascicular, spongioasa, placacortical) care realizeaz, din interior spre exterior,doustructuri:
osul alveolar propriu-zis osul alveolar de suport
osul fascicular i placa cortical joncioneaz lanivelul crestei alveolare, localizat la 1,5-2 mm sub
niveluljonciunii amelocementarecreastaalveolar - definiti ca marginea coronara proceselor alveolare; este rotunjit anterior iaproape plat n aria molarilor
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A, Cement; B, ligament periodontal ; C, placa cribriform; D,maduva hematogen n os spongios; E, os fascicular; F, osspongios
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Osul alveolar propriu-zis (lamina cribla, lamina
dura) corespunde zonei celei mai interne a procesului alveolar:
tapeteaz/limiteaz alveola = punctul de ataament alfasciculelor de fibre din ligamentul parodontal
origine n foliculul/sacul dentar coincide cu osul fascicular multiple perforaii (foramene) care conduc elemente
vasculare i nervoaseplaccribriform/lamina cribla
aspect intens radioopac (lamina dura) evaluarearadiologic este important n patologia periapical iperiodontal
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Osul alveolar de suport
reprezint corpul i limita extern aprocesului alveolar
include spongioasa i placa cortical
n aria diniloranteriori a ambelor maxilare,
osul de suport este subire- la acest nivelnu exist os spongios i placa corticalfuzioneaz cu osul fascicular
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Osul fascicular
osul care tapeteaz/limiteaz alveola = zona subire de os localizat celmai intern n alveol, punctul de ataament al fasciculelor de fibre din
ligamentul parodontaldenumire datorat structurii ifunciei legate de fibrele Sharpey
multiple perforaii cu elemente vasculare i nervoase = placcribriform/lamina cribla
aspect intens radioopaclamina dura
Morfologie:
fascicule de fibre osoase grosiere, mpletite aranjate n lamele subiri,paralel cu axul lung al peretelui alveolar
matricea osoas include i fibrele Sharpey care ptrund n os
perpendicular sau oblic, pe distane variabile i care sunt mineralizatedoar periferic, zona central nefiind mineralizat (ca n cementul celular)
Aici ele sunt mult mai mari comparativ cu cele care se inser n cement
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Osul spongioscomponent al osului de suport, localizat ntre osulfascicular (osul alveolar propriu-zis) i placacorticalos trabecular, care ocup mijlocul proceseloralveolare
Morfologie:os de membran, fibrilar, cu dispunere n lameleParticularitate:
prezenasistemelor Havers n mijlocul trabeculelormaritrabeculele delimiteaz ntre ele spaii areolare,coninndmduvosoashematogen
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Placa cortical
Formeaz zona de suprafa, respectiv placaextern (bucal) i intern (lingual) a proceseloralveolare
se extinde de la creasta alveolar, bucal sau labial,
spre limitele de jos ale alveolelorMorfologie:
os compact fin fibrilar
constituit din lamele longitudinale,circumfereniale, susinute de canale Havers,formnd sisteme haversiene de grosime variabil
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Procesul alveolar interdentar
ntre dou alveole adiacente
Centrul constituit din plcile corticalecorespunztoare, peste care se suprapune, de
ambele pri, osul fascicular care delimiteazinteriorul unei alveole i, respectiv, osul fascicular alceleilalte alveole
Osul spongios apare localizat mai apical, ocupndspaiul de o parte i de alta a plcilor corticale, ntreacestea i osul fascicular corespondent
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A sept interdentar, B ligament periodontal
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Componente structurale
MEC: Componenta anorganic: hidroxiapatita
Componenta organic: matrice amorf i fibrilar
Glicozaminoglicani Proteoglicani Glicoproteine de adeziune:
Osteocalcina
Osteonectina Osteopontina Trombospondina Sialoproteina osoas BMP
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Celule:
Ale esutului osos
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FUNCIILEPROCESELORALVEOLARE
se nscriu n cadrul general al funciilorparodoniului: protecie, susinere iataament pentru dinte
intervin n asigurarea hematopoiezei menin echilibrul mineral
realizeaz (prin vascularizaia i inervaia
proprie) condiiilor de pasaj pentruelementele nutritive, ctre celelaltecomponente ale parodoniului
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Histoarhitectonialigamentului parodontal
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A Dentina
B Cement
C Ligamentperiodontal
D Osteon
E Spaiu interstiial
F, G, Placa cribriform
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Structur
format din celule i matrice extracelular(conine substan fundamental (70% ap,glicozaminoglican n principaldermatansulfatul) i fibre
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FIBRELELIGAMENTARE
Fibrele:
colagen, tip I i tip III; fibrile cu diametru relativ mic (55 nm), ceea ce indic oasamblare fibrilar foarte rapid; organizare n fasciculeoxitalanelaunin
procesul de sintezi degradare a colagenului se desfoar extrem de rapidturnover-ul este mai ridicat n zona central i n extremitatea adiacentproceselor alveolare, dect n extremitatea adiacent cementuluiclasificarea fibrelor are la baz modalitatea de orientare,punctul deplecarei punctul de ancorare: grupul dentoalveolar, cruia i se adaug, fr aaparine direct ligamentului parodontal, un grup gingival
capetele terminale, denumite fibre Sharpey, sunt nglobate fie n cement, fien os
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Fibrele Sharpey tipuri: n tirbuon/spiralate (n cementul primar
acelular)
drepte (n cementul secundar celular i os) fibrele principalerealizeaz cea mai mare partea ligamentului organizate n fascicule bine ndefinite, distincte, vizibile n MO
fibrele principale sunt solidarizate prinintermediul a dou tipuri de fibre identificabiledoar n ME: fibrele indiferente i fibreleintermediare
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Grupul dentoalveolar - n raport cu localizarea,se descriu 5 grupuri diferite:- grupul crestei alveolare
- grupul orizontal- grupul oblic- grupul apical- grupul interradicular
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B - grupul
cresteialveolare
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A - grupul
orizontal
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A - grupul oblic
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A - grupulapical
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A - grupulinterradicular
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Fibrele de oxitalan
fibre elastice imature denumite fibreadiionale
formate din fascicule de microfibrile, aezateparalel
evideniate prin coloraii speciale
localizare preferenial: n jurul pereilorvasculari
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Fibrele de elaunin
constituite din fascicule de microfibrilenglobate ntr-o cantitate mic de elastin
aezate n reea alturi de fibrele de oxitalanplasextins de la cement la os, posibil cu rolde susinere pentru fasciculele de fibre de
colagen
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CELULELE REZIDENTE
1. Fibroblaste
2. Osteoblaste
3. Osteoclaste
4. Cementoblaste5. Resturi celulare epiteliale Malassez
6. Celule mezenchimale nedifereniate
7. Macrofage
8. Celule asociate cu structurile vasculare i nervoase
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CELULA MEZENCHIMAL
NEDIFERENIAT- localizat perivascular- funcie de celul progenitor
- ? o singur celul progenitor pentru celule-fiice(fibroblaste, osteoblaste, cementoblaste)-? mai multe celule progenitor, pentru fiecare
linie n parte
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FIBROBLASTELELIGAMENTARE
principala populaie celular a ligamentuluiparodontal
caracterizate de capacitatea realizrii unui
turnover cu rat extrem de nalt pentrucompartimentul extracelular, n particular pentrucolagen
rennoirea colagenului are loc de-a lungul ntregii
grosimi a ligamentului, i nu n teritorii limitate. MO: celul alungit, fuziform, cu citoplasm
abundenti nucleu oval
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ME: Bogate n organite celulare implicate n sinteza i
secreia proteic: RER, complex Golgi, vezicule desecreie
citoschelet foarte bine dezvoltat: actin, care susinetransformrile morfologice, precum i posibilitile dedeplasare
jonciuni intercelulare, de tip adherensigap
pe suprafa: n regiunile membranei celularedensificate zone de asociere ntre filamenteleintracelulare, filamentele extracelulare ifibronectin, numite fibronexus
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Grad mare de heterogenitate:
remodelarea fibrelor de colagen este realizatnumai de fibroblast care, simultan, este capabil desintez, sau de degradare a colagenului
dovezi experimentale: o singur celul poate ndeplini aceste funcii, fiind deopotriv fibroblastifibroclast
o terminaie a celulei este activ n asimilarea
lanurilor de procolagen, care vor forma apoisuperhelixul moleculei de colagen
cealalt terminaie este activ n fagocitareacolagenului, motiv pentru care conine un sistemlizozomal
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Resturi celulare
epiteliale Malassez
- din teaca Hertwig
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FUNCIILELIGAMENTULUIPARODONTAL
de susinere/de ataament - asigurancorarea/ataarea dintelui n alveola dentar,diminund aciunea forelor fizice externe;creeaz o legtur ntre cement i os
formativ - particip la formarea osului iresorbia osului, formarea cementului
nutritiv - prin vascularizaie
senzorial - rol n perceperea senzaiilor tactile ide presiune
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Histoarhitectonia cementului
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Generaliti
varietate de esut conjunctiv dur, mineralizat,localizat la nivel radicular, cu dispunere n straturiconcentrice n jurul dentinei
alturi de dentini os, aparineaceleiai familii
de esuturi conjunctive specializate, dure,specifice dintelui i are numeroase caracteristicicomune cu osul i dentina, fiind ns mai puinmineralizat dect acestea
mai gros n jurul apexului i n zona defurcaie a dinilor multiradiculari, comparativcu celelalte arii radiculare
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ACEL, acellularcementum
C, crown
CC, coronal cementum
CEL, cellular cementum
CVX, cervix
D, dentinE, enamel
R, root
RC, radicular cementum
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Jonciuni
jonciuneacementodentinar ondulat (uneori) n dentiia decidual,
neted,liniar n dentiiapermanent confer un ataament ferm al cementului de
dentin jonciuneaamelocementar
cementul i smalul se ntlnesc ntr-o
manier de contiguitate la nivel cervical limit de demarcaiedistinct,comparat cuo lam de cuitneted
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Jonciunea dentino -
cementar
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A, coronal cementumC, radicular cementumD, dentinE, enamel
GCT, gingival connective tissueHD, hemidesmosomesIBL, internal basal lamina
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Variante ale relaiei cementului cu smalul
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Morfologie
foarte apropiat de os, prin: prezena celulelor proprii (cementoblaste i
cementocite), localizate n lacune (cementoplaste)
depunerea incrementale, exprimat prin apariialiniilor de cretere
nu conine canale Havers i este completavascular i neinervat
Originean cea mai mare parte mezenchimal
studii recente certific o origine epitelial pentru
anumite teritorii ale cementului
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Structur
Dou componente: anorganic (45-50%) i
organic (50-55%)
componenta anorganic: fosfat tricalcic organizat n cristale de HA, cu
diferenefa de celelalte esuturi dentare dure
componenta organic:
n principal colagen tip Iiglicozaminoglicani caracteristici similare cu colagenul tip I i
glicozaminoglicanii existeni n celelalte varietide esut conjunctiv, specifice dintelui
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Tipuri de cement i funcionalitate
Variante diferite de clasificare, fapt explicabil prinoriginea, structura i funciile deosebite aletipurilor de cement
- elemente de difereniere:
1.Momentul formrii(primar/secundar);
2.Prezena/absena celulelor n matricea depus(celular/acelular);
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3.Originea fibrelor de colagen ale matricei (intrinseci proprii, rezultate prin sinteza cementoblastelor, extrinseciprovenite de la nivelul ligamentului parodontal i consecutivincorporate)
cement primar acelular fibrilar intrinsec
cement primar acelular fibrilar extrinsec
cement secundar celular fibrilar intrinsec cement secundar celular fibrilar mixt
cement acelular afibrilar
cement stratificat intermediar cement stratificat mixt
1 C l i l l fib il
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1. Cementul primar acelular fibrilarintrinsec
localizat imediat adiacent dentinei, grosime de 15-20 m primul element al parodoniului care apare, respectiv
primul cement depus, nainte de formarea ligamentului
parodontal format de cementoblaste care sintetizeaz colagenul din
matricea cementar deci fibrele sunt considerate intrinseci cementoblastele nu rmn incorporate n matrice
fibrele de colagen au o dispoziie paralel cu suprafaardcinii marginea extern = fibroas este zona de conectare a
fasciculelor de colagen provenite din ligamentul parodontal
2 C t l i l l fib il
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2. Cementul primar acelular fibrilarextrinsec
apare imediat dup formarea variantei fibrilare intrinseci,care este baza sa de depunere
acoper cele dou treimi ale rdcinii este extinsi adesea este singurul tip de cement prezent
formare: prin mineralizarea progresiv a fibrelor de colagen provenite dinligamentul parodontal, inserate anterior n marginea fibroas acementului primar acelular fibrilar intrinsec (ME)
aceste fibre de colagen sunt denumite fibre Sharpey
procesul de mineralizare se deruleaz prin depunereasubstanelor anorganice de jur-mprejurul i printre acestefibre
dispunerea fibrelor Sharpey este perpendicular pe fibrele decolagen intrinseci
3 C t l d l l
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3. Cementul secundar celularfibrilar intrinsec
localizat limitat, n regiunile apicale iinterradiculare ale dinilor
aproape ntotdeauna absent n incisivi i canini momentul elaborrii anterior formrii
ligamentului parodontal celule responsabile: cementoblaste diferite
fenotipic de cementoblastele care depuncementul primar acelular, dar similareosteoblastelor
cementoblaste rmn sechestrate n lacune, nmatricea organic, care apoi se mineralizeaz
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4. Cementul secundar celular fibrilar mixt
localizat n treimea apical a rdcinii, apexul putnd fi formatcomplet din cement celular
funcieadaptativ deci are dimensiuni idistribuie inconstante
momentul elaborrii tardiv, dup definitivarea ligamentuluiparodontal sau, uneori, chiar duperupiadentar
Formare:
prin depunerea de cement celular i, concomitent, incorporarean matricea acestuia a fasciculelor de fibre de colagen cu originen ligamentul parodontal
Organizare stratificat lamelar lamelele sunt diferite comparativ cu cele ale cementului primar:
mai larg spaiate, mai distanate, indicnd o rat de formare multmai rapid
conine celule i fibre
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4. Cementul secundar celular fibrilar mixt
Structur celule: cementocite (celule adulte)
situate n lacune i dispuse aleator, dispersat
corp celular ovalar sau poligonal
prelungiri ramificate, radiare, predominantorientate spre PL, situate n canaliculi, seanastomozeaz ntre ele i stabilesc comunicaiichiar cu celulele LP (prin jonciuni gap), dar nurealizeaz un ansamblu sinciional, ca n os
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fibre de colagen intrinseci dispuse paralel cu axul radicular
fine, dens mpachetate
mineralizare uniform
fibre de colagen extrinseci (Sharpey) Perpendiculare pe axul rdcinii
mari, aranjate la ntmplare, ptrund adnc i seramific n matrice
mineralizare neomogen, au miez necalcificat i zonperiferic intens mineralizat
unele penetreaz profund n interiorul stratului decement
4. Cementul secundar celular fibrilar mixt
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5. Cementul acelular afibrilar
localizat n apropiereajonciunii amelocementare
nu are rol de ataare
apare ca o anomalie de dezvoltare, n urma unei
rupturi a epiteliului redus al organului smalului
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6. Cementul stratificat mixt
localizat la nivelul apexului
formparticular de cement: aranjament concentric, n straturi, de cement celular fibrilar intrinsec i
cement acelular fibrilar extrinsec
7 Stratul hialin Hopewell-Smith
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7. Stratul hialin Hopewell-SmithCementul epitelial
Date recente indic existena unui cement fr rol de ataament, localizat ntre
dentini cementul propriu-zis, cu apariie precoce n cementogenezStructur
conine un amestec de produi de sintez ai celulelor ectomezenchimale iepiteliale
are aspectul unui strat amorf, noncolagenic, atubular (lipsit de prelungiriodontoblastice)
prezint proteine asemntoare cu proteinele smalului
are un nalt grad de mineralizare (mai mare dect al dentinei i cementului)
IPOTEZE ASUPRA ORIGINII diferite, datoritcompoziiei sale particulare:
ncadrat ca un tip special de dentinconsiderat ca un esut propriu-zis, incomplet descifrat, prezentat n literatur subdenumirea de stratul hialin Hopewell-Smith
ncadrat ca cement epitelial datorit structurii care include proteineasemntoare cu proteinele smalului
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A- cement acelular B-stratul hialin
C- stratul granular Tomes din dentina D-dentina
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A- cement acelularB- cement celular
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B - Cement celular
A - Cement acelular
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Cementoblaste
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Cementocite
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A, Periodontal ligament
fibers;B, Sharpey's fibers;C, Dentino-cementumjunction;
D, Cementoblasts;E, Acellular cementum
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FUNCIILE CEMENTULUI
implicare n ataamentul dintelui
adaptare la modificrile determinate prin
micrilei uzura dintelui
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Histoarhitectoniajonciuniidentogingivale
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A, Sulcular epithelium; B,Junctional epithelium
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CT, gingival connective tissue
ES, enamel space
JE, junctional epitheliumOE, oral epitheliumSE, sulcular epithelium
EPITELIUL SULCULAR
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EPITELIUL SULCULAR Tapeteaz sulcusul gingival, constituind peretele moale al
acestuia Orientat cu faa spre dinte, frns a fi ataat de smal
Se ntinde de la rebordul marginal gingival pn laepiteliul dejonciune
HISTOLOGIC
epiteliu stratificat pavimentos nekeratinizat subire
ME: RER slab reprezentat, numeroase tonofilamente
membrana bazal de susinere este rectilinie, lipsindcrestele epiteliale
absena keratinizrii datorat, cel mai probabil,inflamaiei permanente a esutului conjunctiv subjacent
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CT, connective tissue GS, gingival sulcus PKE, parakeratotic epithelium
EPITELIUL JONCIONAL
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EPITELIUL JONCIONAL- formunic de epiteliu
- formeaz un guler n jurul regiunii cervicale a dintelui, este ncontact cu suprafaa mineralizat a dintelui, adiacent suprafeeismalului, de la jonciunea amelocementar, extinzndu-secoronar, pe o distan de 2-3 mm, pn la baza sulcusului gingival
- HISTOLOGIC: epiteliu stratificat , subire
- form triunghiular/ evantai: zon mai larg la baza sulcusuluigingival (15-30 rnduri de celule suprapuse) izonngust apical,corespunztoarejonciunii amelocementare (3-4 celule)
- particularitatea structural unic: limitat de dou membranebazale rectilinii, diferite structural:
- o membran bazal extern, care l separ de esutulconjunctiv subjacent;- o membran bazal intern, ataat de dinte, produs
exclusiv de celulele epiteliale
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73/82
Junctional epitheliumCT, connective tissueES, enamel spaceJE, junctional epithelium
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74/82
CT, connective tissue; EBL, external basal lamina; ES, enamel space; IBL,internal basal lamina; JE, junctional epithelium
EPITELIUL JONCIONAL
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75/82
EPITELIUL JONCIONALMembrana bazalintern
- format numai din lamina lucida i lamina densa- lipsa colagenului tip IV- fibrile desprinse din celulele epiteliale de suprafa
penetreaz lamina lucida i lamina densa, pentru a
facilita ataamentul la suprafaa dintelui- ancorarea real - prin intermediul hemidesmozomilor- celulele epiteliale de suprafa funcioneaz
asemntor cu celulele bazale: secret o membran
bazal-like, sau o substancuticular, peste care sepot aduga glicoproteine salivare i depozitebacteriene
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76/82
EPITELIUL JONCIONALStraturi celulare: stratul bazal i stratul suprabazal
1. Stratul bazal- ancorat prin hemidesmozomi de membrana bazal
extern- format din celule cuboidale sau ovalare, cu activitate
mitoticintens2. Stratul suprabazal
- iniial: celule cu iniial un aspect stelat, cu conturneregulat- treptat: caracter pavimentos turtite, aplatizate, cu
dispoziieparalel cu suprafaa dintelui
EPITELIUL JONCIONAL
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77/82
EPITELIUL JONCIONALME:
elemente care difer de cele prezente n celulele epiteliuluigingival din alte teritorii:
cantitatea de RER i de complex Golgi este mai mare
prezente mai puine tonofilamente;
exist lizozomi primari, fagolizozomi, vezicule electronclare careconin structuri rotunde sau vezicule ovalare, electrondense
puini desmozomi, mai frecvent gap ijonciuni strnse
Caracteristicile morfologice: epiteliu nedifereniat imatur (prin IHCs-au analizat keratinele n citoplasma celular i carbohidraiiexisteni pe suprafaacelular)
Diagrama indic drumul celulelor
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78/82
Diagrama indic drumul celulelori fluidelor ntre sulcus i esutulconjunctiv gingival
CT, connective tissueJE,junctional epitheliumOE, oral epitheliumS, gingival sulcusSE, sulcular epithelium
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79/82
EPITELIUL JONCIONAL
turnover-ul epiteliuluijoncionalrat foartenalt 6zile
suprafaa epitelial nu este disponibil pentrueliminarea celulelor astfel c celulele ascensioneaz
spre suprafaa dintelui pn la aproximativ dou-treistraturi de celule distan fa de membrana bazalintern i respectiv smal i se deplaseaz n direciecoronar,paralel cu suprafa dintelui; exfolierea are
loc n sulcus celulele superficiale, continuu nlocuite menin
ataarea cu suprafaa dintelui; ataarea este dinamic,fiind formai noi hemidesmozomi
ESUTUL CONJUNCTIV SUBJACENT EPITELIULUI
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80/82
ESUTUL CONJUNCTIV SUBJACENT EPITELIULUISULCULAR I EPITELIULUI JONCIONAL
exist expresii fenotipice diferite ale esutului conjunctiv subjacentepiteliului sulcular i, respectiv, epiteliuluijoncional
Epiteliul sulcular
esut conjunctiv asemntor celui din corionul epiteliului gingival oral, are
capaciti instructive ce influeneaz maturarea epitelialEpiteliuljoncional - caracter imatur!
esut conjunctiv mai profund, n legtur cu ligamentul parodontal;conine numai factori permisivi, implicai n meninerea epiteliului, nu in maturare; formeaz hemidesmozomi la contactul cu suprafaa dintelui
Diferenele structurale importante pentru elucidarea mecanismelor carestau la baza instalrii bolii parodontale i pentru instituirea unor proceduristomatologice de regenerare ajonciunii dentogingivale
ESUTUL CONJUNCTIV SUBJACENT EPITELIULUI
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81/82
ESUTUL CONJUNCTIV SUBJACENT EPITELIULUISULCULAR I EPITELIULUI JONCIONAL
trsturmorfologicparticular (raport cu lamina propria gingival) deunde prezena unei populaii de celule inflamatorii, chiar n condiiifiziologice
instalarea unui anumit grad de inflamaie este un element aproapenormal la nivelul jonciunii dentogingivale chiar din momentul erupiei
dentarePrezena infiltratului inflamator subjacent epiteliului sulcular asociat cu
dobndirea caracterului epitelial nekeratinizat la acest nivel(experimente animale cu regim strict de igienorali antibiotice duc lakeratinizare)
Concluzia: procesul inflamator este responsabil de transformarea unuimodel de maturaie n altul, prin deprimarea unei trsturi morfologice
Odat cu naintarea n vrst scade nivelul inflamaieiesutului conjunctivi apare o deplasare lent a zonei de ataament, proces denumit
incorect erupiepasiv
Rolul jonciunii dentogingivale n meninerea
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82/82
Rolul jonciunii dentogingivale n meninereaintegritii parodoniului
acioneaz pentru a proteja cementul, ligamentul parodontal iosul alveolar de factorii agresivi dezvoltai n cavitatea oral Dac procesul inflamator depete un anumit grad de
proliferare activ la nivelul epiteliului joncional apare migrareaepiteliuluijoncional cu formarea unei pungi parodontale
deteriorarea i pierderea atarii epiteliale duce la adncireasulcusului gingival elemente care definesc patologiaparodontal
Factori determinanidiveri: inflamaie accentuat a celulelor epiteliale superficiale, de
ataament sau a esutului conjunctiv subjacent rspuns imun la antigeni bacterieni iritaiemecanicdatorat instrumentarului, agresiunii exercitate
de alimente, formrii de plac sau calculi
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