GOOD MORNING GOOD MORNING SUBHO VIJAYA TO ALL

DR PRITI D DESAI ASSOCIATE PROFESSO CONSERVATIVE AND ENDODONTIC DENTISTRY GURUNANAK INSTITUTE OF DENTAL SCIENCE AND RESEARCH, PANIHATI KOLKATA-127

Classification of cavities Dr G.V. black gave the first classification of cavities more than a hundred years ago. It is still being widely used and universally accepted. Dr. G V Black originally divided the lesion in five categories. Dr. Simon had later added the sixth category.

Dr G V Black The scientific foundation for objectives of restoration were also laid down by Dr. G. V .Black more than hundred years. The technique of the preparation of cavities by Dr GV Black placed on a more definite scientific basis for cavity preparation.

Dr G V Black Three principle used for cavity preparation according to Dr G V Black Box shape cavities Beveling of enamel margins where require Extension for prevention

Dr G V Black classification of cavity /caries Divide caries or cavity in to five category Class – I Class - II Class – III Class - IV Class – V Dr Simon added sixth category later Class -VI

Class I cavity/caries Cavities on occlusal surface of premolar and molars Cavities on occlusal 2/3 of buccal and lingual surfaces of molars Cavities on lingual surface of maxillary incisors

Class I cavity/caries

Class I cavity/caries

Class II cavity/caries Cavities occurring on proximal surface of molars and premolars are class II

Class II cavity/caries

Class II cavity/caries

Class III cavity/caries Cavities on proximal surface of anterior teeth that do not involve the incisal angle are class III cavities or caries

Class IV cavity/caries Cavities on the proximal surface of anterior teeth that do involve incisal edge are class IV.

Class IV cavity/caries

Class V cavity/caries Cavities on the gingival third of the facial or lingual surfaces of all teeth are class V.

Class V cavity/caries

Class VI cavity/caries Cavities on the incisal edge of anterior teeth or the occlusal cusp heights of posterior teeth are class IV

Class VI cavity/caries

Class I cavity/caries Line angle Mesiobuccal line angle Msiolingual line angle Distobucaal line angle Distolingual line angle Faciopulpal lien angle Linguopulpal line angle Mesiopulpal line angle Distopulpal line angle Point angle Mesio-bucco-pulpal point angle Mesio-linguo-pulpal point anlge Disto-bucco-pulpal point angle Disto-linguo-pulpal point angle. 21

Class I cavity

Class II cavity/caries Line angle Disto-facial Facio-pulpal Axio-facial Facio-gingival Axio-gingival Linguo-gingival Axio-lingual Axio-pulpal Disto-lingual Disto-pulpal Linguo-pulpal Point angle Disto-facio-pulpal Axio-facio-pulpal Axio-facio-gingival Axio-linguo-gingival Axio-linguo-pulpal Disto-linguo-pulpal

Class II cavity

Class III cavity/caries Line angle Faciog-ingival Linguo-gingival Axio-gingival Axio-lingual Axio-incisal Axio-facial Point angle Axio-faxcio-gingival Axio-linguo-gingival Axio-incisal

Class III cavity

Class IV cavity/caries Line angle Facio-gingival Linguo-gingival Mesio-facial Mesio-lingual Mesio-pulpal Facio-pulpal Linguo-pulpal Axio-gingival Axio-lingual Axio-facial Axio-pulpal Point angle Axio-facio-pulpal Axio-linguo-pulpal Axio-linguo-gingival Axio-facio-gingival Disto-facio-pulpal Disto-linguo-pulpal

Class IV cavity/caries

Class V cavity/caries Line angle Axio-gingival Axio-incisal Axio-mesial Axio-distal Mesio-incisal Mesio-gingival Disto-incisal Disto-gingival Point angle Axiodistogingival Axiodistoincisal Axiomesiogingival axiomesioincisal

Class V cavity/caries

Drawback of black’s classification Blacks classification is simple, easily followed and universally accepted still in certain area of teeth caries occur have been overlooked in that like Carious lesion at line angle of different teeth are not included. Carious lesions on the labial surface of anterior teeth other than cervical third are not included

Drawback of black’s classification Carious lesion on the lingual surface of anterior teeth other than in the cervical third are not included Proximal lesions whether at one side or two sides are taken in one class.

Modification of black’s classification Black’s parameter for classification were controlled by number of factors. These factors are still being followed with slight modification to it. Removal of tooth structure to gain access and to improve visibility Removal of all traces of affected dentin from the floor of cavity

Modification of black’s classification Provision of mechanical retentive designs. Concept of extension for prevention Keeping cavo-srface margins at self cleansing areas.

Modification of black’s classification With advent of newer adhesive materials different cavity designs are followed. Concept of black is controversial and debatable. Tunnel preparation and slot preparation were introduced to avoid undue cutting of marginal ridge.

Modification of black’s classification Mechanical retention design in cavities has been questioned as acid etching and bonding provide sufficient retention claimed by researchers but theses concept is also challanged and it says that it s not ideal substitute of retention form of cavity as given by BLACK. The concept of extension for prevention and keeping proximal margin in self cleansing area has also been questioned Inspite of this the validity of these principle in operative dentistry still exist.

Another classification of carious lesion and cavities Given by Mount 1998. He has classified cavities according to site ans size. He expresses a carious lesions by site and size.

Mount classification Theses classification is according to site and size of lesion. (1)- minimal involvement of dentin-treatments is by remineralization (2)-moderate involvement of dentin-treatments by cavity preparation and remaining sound enamel is saved and support restoration

Mount classification (3)-the cavity is enlarged beyond moderate size. Tooth is weakened by lesion except cusps and incisal edges are split or likely to fail if left exposed to occlusal or incisal load. (4)- extensive caries with bulk loss of tooth structure has already occured

Mount classification site size of the lesion Size of the lesion 1 2 3 4 Pits/fissure - 1 1.1 1.2 1.3 1.4 Contact area - 2 2.1 2.2 2.3 2.4 Cervical - 3 3.1 3.2 3.3 3.4

Mount’s classification It provide option for treatment planning, keeping in mind treatment by adhesive restoration but these classification is not used commonly because There is always a subjectivity in deciding the size of lesion. Treatment planning varies with operator to operator

Mount’s classification Carious sites are also missing like blacks classification Contact caries whether on one side or two side is considered as one only which is misleading. Root caries and crown caries are clubbing

Classification of tooth preparation Keeping in view the simplicity and acceptability of black’s classification is used most commonly. Classification is based on the observed freqauncy of carious lesions on certain aspect of tooth. Although relative frequency of caries locations may have changed over the years the still original classification is used and various classes also are used to identify restorations.

Classification of tooth preparation Classification of tooth preparation that primarily relates to comparison between the more historical tooth preparation is known as conventional preparation and altered preparation designed referred to as Beveled conventional preparation Modified preprations

Conventional tooth preparation Conventional tooth preparation for amalgam includes Uniform pulpal or axial wall depths Cavosurface margin design that results in 90 degree restoration margin Primary retention from derived from occlusally converging vertical walls Beveled conventional preparation with beveling the some accessible enamel margins. Modified preparation design may not have uniform axial or pulpal depths or occusally converging vertical walls.

Other terms used commonly Extension for prevention Enameloplasty Prophylactic odontomy Pits and fissure sealant Bevel

Extension for prevention It is the extension of the cavity preparation in to areas that are caries susceptible e.g. all pit and fissure in occlusal cavity. This principle was conceived by Marshall ebb and later adopted by DR GV Black .

Extension for prevention But nowadays instead of extension for prevention clinicians are doing conservative preparation and caries immunity provided by preventive measure like fluoride therapy, improved hygiene, and diet control, enameloplasty and pit and fissure sealant.

Enameloplasty It is conservative procedure in which narrow pits and fissure in the enamel can ground off with a flam shaped bur to a smooth saucer shaped surface that is easily cleaned.

Enameloplasty

Prophylactic odontomy It is conservative procedure in which the developmental pits and fissures are minimally cut and restored with amalgam.

Prophylactic odontomy

Pits and fissure sealant It is a procedure in which resin sealant is applied on to the deep pit and fissure without cutting any tooth structure.

Pits and fissure sealant

Bevel According to dictionary bevel means any angle other than 90 between the planes and surfaces. Bevels are given at various surface of cavity preparation and tooth for proper marginal adaptation of restoration to tooth.

Bevel Bevel are defined as any abrupt incline between the two surfaces of prepared tooth or between the cavity wall and the cavo-surface margin in the prepared cavity.

Bevel

Bevel Bevels are basically given to reduce the marginal errors ( that is space between restoration and tooth surface).

Bevel Different types of bevels are Ultra short /partial bevel : it involves part of the enamel only.

Short bevel it involve the entire enamel wall

Long bevel it involve all enamel wall and up to one half of the dentinal wall

Full bevel it includes all the enamel and dentinal wall

Hollow bevel it is concave preparation involving only enamel or enamel and part of the dentin

Inverted bevel it is an incline in the labial shoulder for metal ceramic crowns.

Enamel pattern Direction of enamel rods (prism) For better understanding long axis of crown is taken as reference point Rods at the centre of the occlusal surface always lean to pits or fissure towards the axis of the crown. the stronger the inclination of the cusp greater the degree of such slant.

Enamel pattern On periphery of the occlusal surface near the tips of the cusp and crests of the marginal ridges the rods are inclined toward cusp tips or crest away from the long axis of the crown.

Enamel pattern In between the centre and periphery of the occlusal surfaces the rods are parallel to the long axis of the crown Rods at the incisal or occlusal third of the axial surface incline incisally or occlusaly making average of plus(plus means toward incisal or occlusal)with the perpendicular to long axis of the crown at this area.

Enamel pattern Rods at gingival third of the any surface incline by an average of minus(towards the gingiva) from the perpendicular to long axis of the crown at this area.

Enamel pattern Rods at the gingival third of the axial surface incline by an average of minus (towards the gingiva) from the perpendicular to the long axis of the crown at this area. Rods or the middle third of the axial surface perpendicular to long axis of the crown

Enamel pattern

Thickness pattern of enamel Maximum thickness at tip of cusp and crest of triangular, marginal and crossing ridge Thickness decreases from occlusal surface to the depth of the pits, fissure, and grooves

Thickness pattern of enamel Enamel thickness decreases towards gingivally on the axial surface and with least thickness at the cervico-enamel junction

Thickness pattern of enamel Anterior teeth maximum thickness of enamel at incisal edge Lingual enamel plats are generally thinner than the facial and which is more apparent in anterior teeth than posterior teeth

Thickness pattern of enamel As age increases the thickness of the enamel decreases at the occluding area with the result of attrition and also as the mineralization and dehydration of enamel increase by age, the brittleness erasing tendency of enamel also increases.

caries Caries is multifactorial microbial infectious disease of hard structure of tooth characterized by demineralization of inorganic substance and destruction of organic substance of the tooth

Classification of caries Morphology of teeth /Location of caries Severity and Progress of caries Age pattern

caries

Primary caries The original carious lesion in the tooth is referred to as the primary caries. depending upon its location on the tooth it may be pits and fissure caries or smooth surface caries.

Primary caries

Secondary cries Secondary cries is caries begins around or beneath the restoration. Its occurrence is suggestive of an improper seal between the tooth and restoration where micro leakage may occur predisposing to the development of caries. it also referred to as recurrent caries

Secondary cries

Incipient caries Incipient caries is just beginning of the caries activity and the lesion, is evident as a white opaque area on the surface of the enamel. surface inflicted by incipient caries are fairly hard and only minor surface roughing may be present. Hypo plastic white area and incipient carious lesion both look same but in case of hypo plastic area it visible irrespective of whether the tooth surface is a dry or wet while incipient caries become visible only when the tooth surface is dried.

Incipient caries

Incipient caries Incipient caries are at reversible state that it can be rematerialize provided oral hygiene measure are followed and plaque removed and controlled. This remineralised lesion may continue to be white or turn brownish black because of external staining. such dark areas are referred to as arrested caries, they are hard to touch and appear even when the tooth surface is dry or wet.

Advanced or cavitated caries Caries that has progresses to the dentino-enamel junction and is no longer reversible is called advanced or cavitated caries. Here overlying enamel breaks down. at this stage the lesion can not be rematerialized and require cavity preparation and restoration for treatment.

Advanced or cavitated caries

Acute caries Caries of a rapid onset and spread is referred to as acute caries. E.g. nursing bottle caries or rampant caries. Lesions are light yellow in color, soft and highly infectious.

Acute caries

Chronic caries Caries of a slower onset and spread is referred to as chronic caries. Lesion may be present in only few location in the mouth. they are hard and dark brown to black in color. their dark color because of enough time for external staining to occur

Chronic caries

Pits and fissure caries Caries beginning in the pits and fissure of teeth is referred to as pit and fissure caries. Pits and fissure are those areas of the teeth where there is imperfect coalescence of development enamel lobes. because of incomplete fusion of enamel theses areas are susceptible to food impaction and hence caries. While grooves and fosse are area where there is perfect coalescence of developmental enamel lobes which makes them less susceptible to cries

Pits and fissure caries

Pits and fissure caries Pits and fissure caries begins as small point penetration at bottom of pit and fissure ,from here it fans along the enamel rods to the dentino-enamel juction. on reaching dentino- enamel junction caries spreads laterally at the junction and then penetrates towards the pulp through the dentinal tubules.

Pits and fissure caries Diagrammatically pits and fissure caries can be seen as two cones ,base to base, apex of the enamel cone at the point of entry in enamel and the apex of the dentin cone towards the pulp.

Pits and fissure caries

Pits and fissure caries Pits and fissure caries has pin point origin so it may not visible clinically in early stages until the caries has spread largely, undermining the enamel in which case the lesion is seen as a bluish discoloration of the tooth or as a cavitation after the overlying unsupported enamel has been lost under the forces of mastication

Pit and fissure caries/cavities Cavities involving the pits and fissure of the anterior and posterior teeth are referred to as pit and fissure cavities. Pits and fissure on the occlusal surface of premolar and molars and occlusal 2/3 rd of buccal and lingual surface of upper incisors Any other surface where the pit is abnormally present

Pit and fissure cavities

Smooth surface caries Caries involving the smooth surface of the teeth are referred to as smooth surface caries Following are the areas where these may be present Cavities on the proximal surface of incisors, canines, premolars, molars. Cavities in the gingival third of the facial and lingual surface of all the teeth

Smooth surface cavity

Smooth surface caries In smooth surface caries initially it involves a large area of enamel on its outer surface caries then spreads along the enamel rods to dentino-enamel junction. At junction it spread laterally and then towards the pulp through the dentinal tubules. Diagrammatic lesion shows two cones the apex of the enamel cone contact the base of the dentin cone.

Smooth surface caries

Caries pattern

Root surface caries Root surface caries is begins on the roots of teeth that have been exposed to the oral environment and covered with plaque for quite some time. Progression of this type of caries is rapid and hence should be detected and check in time. Because increasing number of elderly who retaining teeth the prevalence of root caries is also increasing for past few years. Root caries also referred to as senile caries.

Root surface caries

Residual caries Caries that remains after the cavity preparation has been completed is referred to as residual caries.which may have been left behind either intentionally by the operator or by accident. Residual caries at the dentino-enamel junction or enamel walls is not acceptable.

Residual caries

Caries Caries in dentin grossly divided in to two zones Infected dentin or outer zone and Affected dentin or inner zone

Affected dentin Affected dentin is characterized by reversible denatured collagen which is not infiltrated with bacteria and is remineralizable. Affected dentin can be left behind during cavity preparation. it either remineralize or remain sterile once cavity is thoroughly restored

Infected dentin Infected dentin is characterized by irreversible denatured collagen which infiltrated with bacteria and is not remineralizabel. Infected dentin should be removed while doing cavity preparation.

Affected dentin & Infected dentin Clinically it is difficult to precisely distinguish between the two zones of dentin caries but guide that helps in distinguishing between them is as follows- Infected dentin is darker than the affected dentin Infected dentin is softer to touch than the affected dentin. 1% solution of acid red in propylene glycol is used to stain infected dentin

Affected dentin & Infected dentin

Line Angle Internal line angle – External line angle Point Angle Cavo-surface angle

Axial Wall Pulpal Wall Internal wall External wall Floor or Seat Enamel Wall Dentinal Wall