Wilkin's ch 17: soft deposits, biofilm, calculus, and stain

biofilm

a primary risk factor for gingivitis, periodontal disease, and caries

soft deposits are referred to as:

-acquired pellicle

-biofilm

-materia alba

-food debris

acquired pellicle

-a thin ( no definite form or shape ), acellular (not divided in to cells), organic tenacious membranous layer formed of proteins, carbs, and lipids

-forms over exposed tooth surfaces, as well as over restorations and dental calculus.

-Its thickness varies and is usually thicker at the gingiva margin.

formation of acquired pellicle

-Within minutes after all external material has been removed form the tooth surface by polishing, it begins to form.

-Fully formed within 30 – 90 minutes

composition of acquired pellicle

Glycoprotien’s from saliva that are adsorbed by the hydroxyapatite of the tooth surface. This material becomes a highly insoluble coating over the teeth, calculus and every thing that is in the mouth.

supragingival pellicle

unstained: clear, translucent, insoluble and not readily visible unless stained with Disclosing solution

surface pellicle

stained; can take on extrinsic stain and become brown, gray or other colors.

subgingival pellicle

is continuous with surface pellicle and is embedded in tooth surface, esp. where there is partial demineralization.

significance of acquired pellicle

-regulation of mineral homeostasis

-host defense/microbial colonization

-lubrication

-attachment of calculus (previous edition of book)

significance of regulation of mineral homeostasis for acquired pellicle

-provides protective barrier against acids, thus reducing caries attack

-may serve as scaffold for remineralization

-may protect against erosion

significance of host defense/ microbial colonization for acquired pellicle

-about 8% of proteins have antimicrobial function

-some of the proteins inhibit binding and some promote binding

significance of lubrication for acquired pellicle

-keeps surfaces moist and prevents drying 

-enhances speech and mastication 

-may also protect against abrasive damage 

removal of acquired pellicle

-not resilient enough to withstand oral self care, abrasive toothpaste, whitening products, acidic food, and acidic drink

-pellicle will reform shortly after

stages in biofilm formation

1-pellicle formation

2-initial adhesion

3-maturation

4-detachment and dispersion

pellicle formation stage in biofilm formation

pellicle provides glycoproteins for microorganism adherence 

initial adhesion stage in biofilm formation

-Microcolonies multiply in layers, creating a 3 dimensional structure.

-Organisms within the biofilm in the first few hours are mostly gram-positive cocci and rods.

-Matrix Formation: Bacteria continue to secrete EPS.

-components of the EPS matrix are: polysaccharides (sticky and contribute to plaque adhesion to tooth), glucans and fructans and levans. Also antimicrobial enzymes to protect the biofilm

maturation stage in biofilm formation

-Cell to cell communication “quorum sensing”.

-This helps to control the growth of the bacterial community by letting them know when to move to find new food sources.

-More bacteria will adhere to the biofilm and grow in mass/thickness.

-Occurs by 72 hours

detachment and dispersion stage in biofilm formation

As the colonies mature they release planktonic cells and the process starts all over.

changes in biofilm microorganisms day 1 to 2

-primarily gram-positive cocci.

-Streptococcus mutans and Streptococcus sanguis.

-Small amount of leukocytes.

changes in biofilm microorganisms day 2 to 4 

-cocci still dominant with increasing number of gram positive filamentous form.

-Slender rods join the surface with more leukocytes.

-Giving a “corn cob” appearance and secreting EPS.

-Biofilm can mature by 72 hours and capable of initiating the inflammatory process.

changes in biofilm microorganisms day 4 to 7

-Filaments increase and a more mixed flora appears with rods, filamentous forms and fusobacteria.

-Plaque near the gingival margin thicken and mature with more spirochetes and vibrios, gram- negative.

-More leukocytes

changes in biofilm microorganisms day 7 to 14

-Vibrios and spirochetes (mature flora) appear and number of WBC increases.

-As the plaque matures and thickens, more gram- negative and anaerobic organisms appear.

-Signs of gingival inflammation are now observable.

changes in biofilm microorganisms day 14 to 21

-Vibrios and spirochetes are prevalent in the older colonies with cocci and filamentous forms in the younger plaque.

-Clinical signs of gingivitis are evident.

supragingival biofilm

-2 layers of gram-positive aerobic bacteria

-First layer = basal layer that adheres to tooth surface and is made of streptococci, actinomyces, filamentous bacteria, yeast and lactobacillus

-Second forms over first and has greater amount streptococci and Lactobacillus

-Caries

subgingival biofilm

-Apical proliferation (rapid growth) of MO from supra plaque.

-4 layers, first also called basal

-Microorganisms:

• Invade the underlying connective tissue.

• anaerobic and predominately gram negative.

-Perio

composition of bacterial biofilm 

-MO and EPS = 20% of biofilm, organic and inorganic solids

-Water = 80%

inorganic elements of biofilm

-Calcium

-Phosphorus

-Magnesium

-Fluoride

organic elements of biofilm

-Carbohydrates (polysaccharides)

-Proteins

distribution of dental biofilm by location

-supra: coronal to gingival margin

-gingival: forms on external surface of oral epithelium and attached gingiva

-sub: between periodontal attachment and gingival margin within the sulcus

-fissure: develops in the pits and fissures of the teeth

distribution of biofilm by surfaces

-during formation

-tooth surface

distribution of biofilm during formation

-Begins at gingival margin esp. at proximal surfaces and extends coronally.

-Increases toward the gingival third and on toward the middle third of crown.

distribution of dental biofilm by tooth surfaces involved

-Most frequently on lingual, proximal surface and posterior.

-Least amounts occur on the palatal surfaces of maxillary teeth due to activity of tongue.

factors influencing accumulation of biofilm 

-Crowded teeth

-Rough tooth surfaces

-Difficult to clean areas: overhanging margins of crowns

-Teeth not in occlusion

ways to detect biofilm

-direct vision

-tactile examination

-disclosing agents

-clinic record

detection of biofilm by direct vision

-thin plaque may be translucent and difficult to see

-but thicker plaque appears dull, dingy with a matted-fur look.

-Sometimes can be stained by food / tobacco etc.

detection of calculus by tactile examination

-With probe or explorer:

-Slippery but as it begins to calcify feels rough.

detection of biofilm by clinic record

-Slight, moderate or heavy

-Index

-Biofilm score

significance of bacterial biofilm

-plays a major role in the initiation and progression of dental caries and periodontal disease

-formation of dental calculus (mineralized biofilm)

dental caries

-characterized by demineralization of mineral content of teeth 

-essentials for decay:

• cariogenic microorganisms

• pH levels

• effect of diet

cariogenic microorganisms

-In acidic environment bacteria will initiation a carious lesion.

-Xerostomia / fermentable carbohydrates will create a more acidic environment thus increasing demineralization.

pH of biofilm

-Acid formation begins immediately / cariogenic food / into biofilm = rapid drop in pH

-Demineralization = time and frequency the pH is below critical level

critical pH for enamel 

5.4 to 5.5

critical pH for dentin

6.2 to 6.4 (6.7)

In a high fermentable carbohydrates diet biofilm will gradually increase its pH lowering ability

pH of plaque

-Before eating pH is 6.8 to 7.3. The lower the pH the more decay susceptible the person is.

-Upon sucrose intake pH drops rapidly

-Enamel demineralization occurs between 5.4 to 5.5. Root demineralization: 6.2 to 6.4 (6.7)

frequency of carbohydrate intake

-pH lowered each time sucrose is taken in and takes > I hour (30

minutes) to return to normal.

-Frequency is a more important factor than the amount of sucrose.

• Pie, all at one time

• Wait 30 minutes to brush = pH return to normal (neutral)

texture of diet

chewing coarse food cleans

factors that contribute to decay

-pH

-frequency of carb intake

-texture of diet

materia alba 

loosely adherent mass of bacteria and cellular debris that occurs on top of plaque.

clinical appearance of materia alba

-a bulky soft deposit that is clearly visible.

-It is white or grayish-white and resembles cottage cheese.

origin of materia alba

-from the accumulation of living and dead bacteria, desquamated epithelial cells, disintegrating leukocytes, salivary proteins and food debris.

-can be removed with water spray or oral irrigation where plaque can’t

food debris

-After eating food can collect around the cervical 1/3 and proximal embrasures like:

• Diastemas

• Poorly contoured restorations

-Can lead to Unsanitary conditions such as: 

• Caries

• Periodontal issues

• Halitosis

calculus

-Mineralized bacterial plaque - hard, tenacious mass that forms on natural teeth as well as on dentures and prosthesis.

-classified by its location of supragingival or subgingival calculus

significance of calculus

Rough surface hold disease producing bacterial plaque close to gingival tissues, perpetuating inflammation.

location of supragingival calculus 

coronal to gingival margin 

distribution of supragingival calculus

-Lingual of ↓anterior

-buccal of ↑ 1’st and 2’nd molars

-May attach on any hard surface

appearance of supragingival calculus

when dried with compressed air it may appear chalky white or be stained by tobacco or food products.

location of subgingival calculus 

apical to the gingival margin and may extend nearly to the bottom of the pocket.

distribution of subgingival calculus

-Generalized or localized on any teeth.

-Related to areas difficult to clean.

appearance of subgingival calculus

-may be dark because of pigment from blood found in sulcular fluid.

-Radiographic exam.

-Dark edge of calculus may be seen just below margin.

-Diseased tissue is loose and may permit view into pocket when air is used to deflect tissue.

-Transillumination reveals a dark shadow.

-Tactile examination: may feel grainy to large bumps.

calculus composition

-Inorganic and organic compounds

-Differs with age, hardness of deposit and location

-Maxillary molars tend to be higher in calcium, phosphorus and ash than lingual mandibular anterior teeth

major component of inorganic content of calculus

-Calcium

-phosphorus

-carbonate

-sodium

-magnesium

trace elements of inorganic content of calculus 

-copper

-zinc

-strontium

-manganese

-silicon

-fluorine

-iron

-potassium

fluoride as inorganic content of calculus

-↑ in supra than sub

-Depends on patient exposure

crystals as inorganic content of calculus

-mostly hydroxyapatite

-small amounts of brushite, whitlockite, and octacalcium phosphate 

calculus compared to teeth and bones

-Enamel is the most highly mineralized tissue in the body

-95 to 97% inorganic salts

-65% for dentin

-45 to 70% for cementum and bone

organic content of calculus

-Microorganisms

-Epithelial cells

-Leukocytes

-Fatty acids

-Phospholipids

-Proteins

calculus formation

-Subgingival calculus does not develop by direct extension from supra calculus.

-Subgingival plaque forms by extension of supragingival plaque

-Each plaque mineralizes separately

3 basic steps of calculus formation

-pellicle formation

-biofilm formation

-mineralization

early formation of calculus

-MO adhere to the pellicle.

-Form areas of mineralization centers.

-Undisturbed 24 – 72 hours more centers develop, grow and expand = unite.

-Some MO will start to calcify.

-Calcium phosphate crystals bond directly to enamel and cementum.

source of minerals for supragingival calculus 

saliva

source of minerals for subgingival calculus

-gingival crevicular fluid

-inflammatory exudate (pus)

mechanism of calculus mineralization

-supersaturation of saliva

-calcium inhibitors are pyrophosphate and zinc salts

-heavy calculus formers have high salivary levels of calcium and phosphorus

structure of calculus 

-Layers that are more or less parallel to tooth surface.

-Layers are separated by pellicle that is deposited over previously deposited calculus.

-Lines or layers called “incremental lines”.

-Lines grow on top of each other in new layers.

-Surface of calculus is rough.

outer layer of subgingival calculus

-partially calcified

-soft layer of dental biofilm

-Biofilm is in contact with the epithelial lining of the pocket causing constant irritation leading to more destruction of tissue.

types of calculus deposits

-Crusty, spiny or nodular

-Ledge or ring

-Thin, smooth veneer like

-Finger or fernlike extensions

-Individual island or spot

-Supra or sub

formation time of calculus 

-Average time for soft deposit to mature mineralized state is 12 days

-Mineralization can begin as early as 24 – 48 hours.

factors that influence formation time of calculus

-Oral hygiene habits

-Genetics

-Diet

-Bacterial load

attachment of calculus

-Ease or difficulty of removal is dependent on manner of attachment to tooth surface.

-can be attached by:

• acquired pellicle

• mechanical locking

• direct contact between calcified intracellular matrix and tooth surface

attachment of calculus by acquired pellicle

-attaches superficially to pellicle;

-no interlocking or penetration occurs.

-Easily removed.

attachment of calculus by mechanical locking

-minute irregularities in the tooth surface are entered by plaque and it then mineralizes.

-Occurs on cementum and enamel.

attachment of calculus by Direct contact between calcified intracellular matrix and tooth surface

interlocking of inorganic crystals of tooth with mineralizing plaque

clinical implications of calculus 

-Sub calculus contains pathogenic bacteria that causes inflammation and destruction of tissue which causes loss of attachment and deepening of the pocket.

-Increased pocket depth = an increase in places where plaque can accumulate = increase in bacteria that cause deepening of the pocket.

-Calculus is mineralized plaque. Sub calculus is always covered by an active plaque layer that causes an increase in bacteria. This layer is in contact with the epithelium of the pocket.

-Calculus is a predisposing factor (secondary etiologic factor) in pocket development in that it provides a reservoir for the collection of bacteria and endotoxions on the rough surface.

supragingival exam by direct examination

may be seen directly or indirectly using a mouth mirror

supragingival exam by compressed air

-small amounts are invisible when wet

-drying with air makes them visible

subgingival exam by visual examination

-Dark edges can be seen at just under gingival margin

-Air to deflect margin making deposit visible

-Transillumination to see proximal deposits

subgingival exam by color change

dark calculus may be visible as a dark shadow along the gingiva and subject the presence of calc

subgingival exam by tactile examination

using a probe or explorer, it will be detected

subgingival exam by radiographic examination 

can detect large deposits on proximal surfaces

subgingival exam by dental endoscopy

used in deep pockets/furcations can detect undetectable calc esp. burnished or veneer like calculus

prevention of calculus

-Very simply efficient plaque removal. Including a regimen of brushing and

flossing.

-The use of a Tartar Control Toothpaste can help. These products contain a pyrophosphate or zinc citrate. They inhibit calculus crystal growth = decrease in calculus.

personal dental biofilm control by OHI for calculus prevention

-Hands on demonstration

• Appropriate aids for patient needs

-Follow up at re-call appointments

• Review and refine techniques

-Identify dietary contributors

• Sugar

• Fermentable carbohydrates

professional care for prevention of calculus

-Patient need to maintain regular prophy appointments.

-Routine removal of deposits will help keep levels of sub and supra low.

anticalculus dentifrices

-Calculus control products help to inhibit calculus growth.

-No effect on existing calculus deposits.

-“Tartar Control”

• Mouth rinses or dentifrices

  • Inhibit mineralization of biofilm

  • Pyrophosphates

  • Zinc citrate

  • Triclosan

classification of stains by location 

extrinsic and intrinsic stain 

extrinsic stain

-occurs on the external surface of the tooth

-removed by toothbrushing

-scaling and/or polishing

intrinsic stain

-occurs within the tooth

-cannot be removed by toothbrushing or scaling and/or polishing

-Fluorosis

-Leaching out of amalgam into tooth structure

classification of stain by source 

exogenous and endogenous stain 

exogenous stain

-develop or originate from sources outside the tooth.

-May be extrinsic and stay on the outer surface of the tooth or intrinsic and become incorporated within the tooth structure.

endogenous stain

-develop or originate from within the tooth.

-These stains are always intrinsic and usually are discolorations of the dentin reflected through the enamel.