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Pulpal irritation and devitalization as a result of preparation of teeth for complete crowns
LIEBAN . . . VO LUM E 51, DECEMBER 1955 • 679
in the walls. These will contaminate the developer and chemical fog will be the result. C O N C L U S IO N S
Fog is a constant threat to quality. Good housekeeping will prevent it. A process
ing room should be as clean and efficient as any other room in the dental office. Manufacturers’ directions should be fol lowed as carefully as with any other materials used in dentistry. I f the dentist does his part, he should never be troubled by fog.
343 State Street
Pulpal irritation and devitalization as a result of preparation of teeth for complete crowns E. Alan Lieban, D.D.S New York
W ith the current trend toward complete oral rehabilitation involving the prepara tion of teeth for complete coronal cover age and cementation of the crowns, many pulps are irritated needlessly, often re sulting in devitalization. Some operators
stances. There is an advantage in pre paring a tooth without anesthesia, for the patient can alert the operator when the tooth becomes sensitive, thus avoid ing any potential pulp irritation from overheating. ■
use local anesthesia when preparing a cavity. W ith this method there is a less ened circulation to carry off the intense heat that may be generated if no pre cautions are taken to avoid overheating the tooth. After the anesthetic effect has worn off, a freshly prepared tooth may become sensitive and remain so until a
Grinding speed and pressure are two factors which affect the generation of heat. Rapid grinding with light pressure against a tooth will not create the amount of heat that will be generated by heavy pressure in slow grinding. Cutting should be done gradually by intermittent pres sure and release to prevent heating. It is important that cutting instruments be sharp. Dull instruments, especially when used with heavy pressure, cause a bur nishing effect which creates heat.
true pulpitis sets in. Instead of merely pausing occasionally to allow the tooth to cool, the dentist should use some type of water spray unit to overcome heat generated by frictional contact of the cutting instrument against the tooth surface. Such a unit may be used as an adjunct under all circum
Presented before the Eastern Dental Society, delphia, January 20, 1955.
Phila
480 • THE JO U R N A L OF THE A M ER IC A N DENTAL ASSOCIATION
F A C T O R S C A U S IN G P U L P A L
is invaded by bacteria through the den
IR R IT A T IO N A N D D E V IT A L IZ A T IO N
tinal tubules. The time required for an infected pulp to become completely de vitalized varies from a matter of days to years. Pulp degeneration may occur with
Cutting away too much tooth structure is a common fault, particularly in shoulder preparations. N o more tooth structure should be sacrificed than is actually necessary. The preparation of a tooth for a complete crown should be completed in one visit. Immediately after the im pression is completed the prepared tooth should be protected adequately from saliva and other irritating factors. Hypersensitiveness, especially at the cervical third of the crown, often results from failure to protect the exposed den tin. I f this condition is neglected, it may result in hyperemia which may develop into a true pulpitis. Normally, a simple and effective safeguard is to dry the tooth thoroughly, apply eugenol over the entire surface, and then volatilize the eugenol with warm air. T h e prepared tooth then should be covered completely with a temporary crown form lined with an effective agent; for example, zinc oxide and eugenol or surgical cement. A n opening should be made in the crown form on an appropriate surface to allow the excess liner to escape. Any temporary occlusal stress should be re lieved. Hypersensitiveness often can be relieved by the use of an astringent agent which will coagulate the dentinal fibers. Ammoniacal silver nitrate when applied to a deeply cut tooth surface is effective in relieving this condition, but its applica tion is limited to uses where discoloration is not objectionable. Whenever possible it is desirable to allow a few weeks to elapse until secondary dentin seals the injured tubules, and thus decreases sensitivity.
Deep-Seated Caries
• Before proceeding, the patient should be interrogated as to any history of pain. Clinical examination should include vitality and other tests, and periapical and bitewing roentgeno grams. In the presence of deep caries the pulp
out any clinical signs or symptoms. V i tality tests may indicate a vital pulp, al though the entire coronal portion of the pulp may be necrotic and the periapical roentgenographic evidence may be nega tive. All caries should be removed. In some instances after excavation the pulpal wall of the cavity will be close to the pulp. Sometimes the pulp is exposed directly; no attempt should be made to save such a pulp. W h en a tooth is amenable to endodontic treatment, such a procedure should be undertaken before noticeable inflammatory changes occur. A n aseptically filled pulp canal is more desirable than a diseased pulp. I f the tooth is to be retained, every effort should be made to disinfect the involved tubules after the exclusion of saliva. Caustic and irritating drugs should be avoided. Antiseptics having a seda tive quality combined with penetrating power are beneficial when applied to t h e ' exposed surface and volatilized with warm air; for example, beechwood creo sote or metacresyl acetate. A good cavity lining or varnish may then be applied to the exposed surface and allowed to set before it is covered with a thin cement. Another method is to insulate the floor of the cavity with a thick paste of zinc oxide and eugenol, covered by a layer of thin cement. Pulp tests should be made and roent genograms taken at intervals to deter mine the condition of the tooth. If increasing sensitivity results, the only re course is endodontic treatment or extrac tion.
Pulp Capping
• Clinical observations and histological investigations show that in adults most instances of vital pulp exposures followed by £ulp capping re
LIEBAN . . . VO LUM E 51, DECEMBER 1955 • 681
suit in inflammation of the pulp tissue with subsequent necrosis of the pulp, rather than in the formation of repara tive hard tissue. This has led to the gen eral belief that attempts to save adult pulps exposed by caries are contraindi cated.
Improper Adaption of Crown at Cervix • A ledge will occasion food impaction. If not corrected, such a condition will eventuate in a gingivitis and ultimately in alveolar resorption. Food debris will also cause décalcification and disintegra tion of the cementum. Dentin underlying cementum is permeable, and caries prog resses pulpward rapidly, frequently in volving the pulp. After the crown is adapted, roentgeno grams should be taken of the prepared tooth prior to cementation. This proce dure is important to ascertain whether the open end fits correctly at the cervix. A bitewing film, taken at the proper angle, is advocated in preference to the regular periapical film in order to avoid distortion. This should be supplemented by examination with an explorer.
Failure to Relieve Traumatic Occlusal Stress • Any complaint of soreness in a tooth should be investigated. Trauma may be traceable to a high spot on the incisal edge or occlusal surface. The entire occlusal surface may be involved. Occlusal correction involves some means of accurately recording and relieving such spots. Traumatic occlusion, if neg lected, will injure the periodontal tissues of the teeth. In some instances this in jury may cause circulatory changes re sulting in pulp hyperemia. Even when the occlusion is correct at the time of insertion of a crown or bridge, it may become faulty as time goes on. It is ad visable to recheck the occlusion occa sionally, even though the patient may not complain of discomfort. Gold crowns are less apt to break than porcelain crowns and may show wear
comparable to the wear of natural teeth, especially in mouths of patients who mas ticate forcefully.
Excessive Periodontal Involvement
• A careful diagnosis should always precede fixation of loose or drifting teeth. If the diagnosis is doubtful, a reputable perio dontist should be consulted. Resorption of the alveolar bone and widening of the periodontal membrane are manifested clinically by loosening of the teeth. Where a tooth has lost approximately more than one half of its bony support, the prognosis is not favorable. Some operators splint loosened teeth if there is extensive periodontal involve ment. T h e prognosis for such teeth may be definitely hopeless because of mobility and loss of supporting structures. If sev eral periodontally involved teeth are united by a fixed splint, and one of these teeth is not amenable to treatment, the splint is holding a tooth that should be extracted; retention of such a tooth will cause disease to spread to the adjacent teeth. It is illogical to attach bridgework to diseased teeth. The disease should be eradicated before the bridge is planned. Pulpitis may result from the extension of a periodontal pus pocket that invades the periapical area, a condition more prevalent in posterior teeth. Under these circumstances, endodontic treatment or the removal of the tooth is advocated.
Recession of the Gingiva • Patients’ teeth with exposed cementum are usually sen sitive to sweets, acids or thermal changes. Caries of cementum sometimes occurs when the gingiva has receded, exposing the cementum to saliva. Generally, there is a triangular depression bounded by the gingival margin, cementum and enamel. This may collect bacterial plaques, and caries of the cementum may develop. Later the dentin is invaded; however, there may be a gingival recession without the presence of caries. Plaques should be removed by scaling, and the patient
682 • THE JO U R N A L OF THE A M ER IC A N DENTAL ASSOCIATION
taught to avoid recurrences by proper home care. W hen caries has progressed to an appreciable extent the prognosis depends in a large measure on the preparation of the cavity and method of restoration that has been applied. T h e care given after wards by the patient is important. Neglect may cause hyperemia and produce par oxysms of pain. Irritation of the pulp may cause inflammation and subsequent devitalization.
Protection of the Prepared Tooth with a Temporary Crown Form • T o protect the anterior tooth temporarily, acrylic or celluloid crown forms are preferable esthetically. T o avoid disharmony in shade, the celluloid crown may be lined with synthetic cement. Before the cement sets, the adapted crown should be withdrawn, trimmed and lined with a protective medium, as with other types of tempo rary crowns. Alum inum or gold shell crowns generally are used only for pos terior teeth. These may be adapted di rectly to the prepared teeth or may be swedged on the dies of the prepared teeth. Temporary acrylic splints may be constructed to cover completely a num ber of adjacent prepared teeth. Regard' less of what type of temporary crown or splint is used, it should be lined with an effective obtundent.
Protection of Dentin Prior to Cementa tion of Permanent Crown • Vitality of a pulp may be impaired by the use of some irritating agent. Phosphoric acid in the cement may cause chemical irritation when the cement is forced into deeply cut, unprotected dentinal tubules. The prepared tooth when ready for cementa tion should be kept dry by using cotton rolls and the saliva ejector. The entire tooth surface should be dried with warm air, and any adherent temporary protec tion removed cautiously. Eugenol should be applied and volatilized with warm air. Ammoniacal silver nitrate precipitated
by eugenol may be used as an added precaution, where discoloration is not objectionable. As a final step in the prep aration for cementation, the tooth sur face should be dried thoroughly and coated with a cavity varnish. T h e cavity lining should be set prior to the actual cementation.
Cementation ' Cement mixed incorrectly may generate enough heat to cause pulpal irritation. A zinc cement that complies with American Dental Associa tion specifications is advisable. T h e direc tions of the manufacturer should be fol lowed. Inclusion of saliva beneath a crown or the imperceptible shifting of a crown during placement are causes of septic dentin. Excessive hammering in fitting, removing and cementing a crown is irritating to the pulp. Pressure of a cemented crown on a thin lamina of softened dentin covering the pulp may cause a pulpitis. T h e pulp is intolerant to pressure, and reacts vigorously when subjected to compression.
D IA G N O S IS O F O B S C U R E P A IN
A t times a patient who has undergone complete oral rehabilitation may com plain of a sore tooth or toothache. This may be mild or excruciating pain. The quality of pain as expressed by the pa tient is a relative term, and may be no guide to the intensity of the pain. Any complaint registered by the patient should be investigated carefully. Pain may be due to a temporoman dibular disturbance, neuralgia, traumatic occlusion, a periodontal condition, tooth surface sensitivity, pulp nodules, an in volved pulp or a combination of any of the aforementioned factors. Pain may be localized or referred. Until a pulp be comes involved, pain usually remains localized; with pulp involvement, re ferred pain may be pronounced. After the pulp has become devitalized, referred pain ceases, and any manifestation of
LIEBAN . . . VO LUM E 51, DECEMBER 1955 • 683
local pain is due to an involvement of the periodontal structures. It is not un usual to have pain referred to the region of another tooth. Each tooth has a sepa rate area of pain reference. Often the patient is unable to localize the source or even the nature of the pain. A t times the patient can point to the quadrant in which the pain occurs, but is unable to designate a particular tooth. Occasion ally, several teeth may be involved in different areas simultaneously.
C L IN IC A L PR O C E D U R E S
A correct diagnosis is contingent on a good subjective and objective examina tion with various clinical tests. The pa tient is requested to point out the painful tooth, and to describe the character of the pain, whether throbbing or dull, constant or intermittent. If intermittent, where, at what time and under what cir cumstances is it felt? Is it aggravated by thermal changes, or are such changes without influence in increasing or dimin ishing the pain? Is the pain associated with localized tenderness? For how long a period has the pain been experienced? This interrogation may be supplemented by a visual examination and clinical tests to substantiate a correct diagnosis. Judg ment will aid in interpreting diagnostic symptoms. If an acute dentoalveolar abscess is present, free drainage should be estab lished for the evacuation of pus and relief of pain. Attempts to establish suf ficient drainage through the pulp canal frequently are disappointing and are re sorted to only as temporary means of relief in instances where the tissue is not fluctuant. Where there is evidence of pointing on the surface, an incision is made in the soft tissue down to the bone, over the point of greatest tenderness. This is around the tooth apex. A n inci sion should be made only if the tissue is soft and fluctuant. A gauze strip is in serted for drainage. Penicillin, 500,000
units, is administered daily for three consecutive days. H om e care involves in termittent applications of ice packs over a moist cloth and frequent rinsing with a warm saline solution. After the acute symptoms have subsided, the tooth is treated as an infected pulpless tooth. Clinical procedures should include roentgenographic examination and ther mal, percussion, palpation, mobility and, if necessary, anesthesia tests. N o one method of pulp testing is entirely de pendable. Although it may not always be necessary to utilize all these tests for a given case, under certain circumstances it may be preferable to use two or more tests in order to arrive at a correct diag nosis.
Roentgenographic Examination • Stand ard intraoral films are used normally. In instances of vague pain, bitewing, oc clusal and extraoral films may be in cluded. T h e roentgenogram should be examined for a thickening or break in the line of the periodontal membrane at the tooth apex. The bone surrounding the apex should be examined for any periapical rarefaction, and the presence or absence of the lamina dura noted. Thermal Tests • For the heat test a small pellet of heated gutta-percha or the hot air blower should be applied labially or buccally, midway between the cervix and incisal or occlusal surface of the sus pected crowned tooth. H eat will occasion a quick painful response from a suppu rating pulp. For a simple cold test, a small pellet of cotton may be saturated with ethyl chloride, and applied as indi cated earlier. Sufficient time should be allowed for evaporation of the ethyl chloride to chill the tooth. Another method is to spray ethyl chloride directly on the questionable tooth after it has been isolated by the rubber dam. In interpreting responses to thermal changes, the dentist must be mindful of the fact that sometimes normal pulps
684 • THE JO U R N A L OF THE A M ER IC A N DENTAL ASSO CIATIO N
respond painfully, especially to cold. Hypersensitive dentin, hyperemic pulp or an acute pulpitis will react painfully to extreme cold. Teeth vary markedly in their tolerance to heat or cold. Adjacent teeth offer a control. T h e alternate appli cation of heat and cold may elicit a response, when either extreme alone may be ineffective. Nonvital teeth will not respond to either heat or cold. T h e electric pulp test for teeth with complete crowns is achieved by first making an opening of sufficient diameter through the crown to expose the dentin directly. T o avoid contact with the sur rounding area, the electrode should be coated with a nonconducting agent ex cept at the extreme tip. Chlorapercha may be used for this purpose.
Percussion Test
• In the percussion test the crown of the tooth is tapped m od erately with the blunt end of an instru ment. In the early stage of pulp inflam mation a tooth will not be sensitive to percussion. W hen periapical inflamma tion is present there will be a noticeable response. In a case of traumatic occlusion or a periodontal condition the tooth is usually sensitive to percussion. Adjacent teeth should be tapped also, so that the patient may distinguish any difference in discomfort. This test is not practical where two or more crowns are soldered together; tapping on one tooth will regis ter in all the other teeth throughout the segment.
Palpation Test
• In the palpation test slight pressure with a finger tip is applied
on the soft tissue over the root apex. Pain is felt when the periapical region is inflamed. In inflammatory conditions of the pulp which involve the periodon tal tissue, the presence of tenderness or pain to percussion or palpation is patho gnomonic.
Mobility Test
• The extent of mobility may be determined by moving a tooth labiolingually. T h e degree of abnormal
mobility will determine the extent of periodontal involvement.
Anesthesia Test
• Where pain is radiated and unilateral, the mandibular alveolar process may be anesthetized to determine the quadrant. If the pain subsides, it may be inferred that a mandibular tooth is involved. If the pain persists, it would indicate the involvement of a maxillary tooth. After this procedure, infiltration of each maxillary tooth in the quadrant may be done until the painful tooth is located. If bilateral diffused pain is present, the dentist may resort to a mandibular al veolar injection on both sides. Sufficient time must be allowed for the anesthesia to become effective on one side before the other side is anesthetized. If two or more mandibular teeth are present in a quadrant, in order to ascertain which tooth may be involved, the dentist must wait until the anesthetic effects have worn off before proceeding with other tests. T h e final diagnosis is based on the information obtained from a careful in terpretation of all the facts, and usually is a diagnosis by exclusion.
30 West 59 Street
Words • Nowadays a word is a deed whose consequences cannot be measured. Heinrich Heine.
in the walls. These will contaminate the developer and chemical fog will be the result. C O N C L U S IO N S
Fog is a constant threat to quality. Good housekeeping will prevent it. A process
ing room should be as clean and efficient as any other room in the dental office. Manufacturers’ directions should be fol lowed as carefully as with any other materials used in dentistry. I f the dentist does his part, he should never be troubled by fog.
343 State Street
Pulpal irritation and devitalization as a result of preparation of teeth for complete crowns E. Alan Lieban, D.D.S New York
W ith the current trend toward complete oral rehabilitation involving the prepara tion of teeth for complete coronal cover age and cementation of the crowns, many pulps are irritated needlessly, often re sulting in devitalization. Some operators
stances. There is an advantage in pre paring a tooth without anesthesia, for the patient can alert the operator when the tooth becomes sensitive, thus avoid ing any potential pulp irritation from overheating. ■
use local anesthesia when preparing a cavity. W ith this method there is a less ened circulation to carry off the intense heat that may be generated if no pre cautions are taken to avoid overheating the tooth. After the anesthetic effect has worn off, a freshly prepared tooth may become sensitive and remain so until a
Grinding speed and pressure are two factors which affect the generation of heat. Rapid grinding with light pressure against a tooth will not create the amount of heat that will be generated by heavy pressure in slow grinding. Cutting should be done gradually by intermittent pres sure and release to prevent heating. It is important that cutting instruments be sharp. Dull instruments, especially when used with heavy pressure, cause a bur nishing effect which creates heat.
true pulpitis sets in. Instead of merely pausing occasionally to allow the tooth to cool, the dentist should use some type of water spray unit to overcome heat generated by frictional contact of the cutting instrument against the tooth surface. Such a unit may be used as an adjunct under all circum
Presented before the Eastern Dental Society, delphia, January 20, 1955.
Phila
480 • THE JO U R N A L OF THE A M ER IC A N DENTAL ASSOCIATION
F A C T O R S C A U S IN G P U L P A L
is invaded by bacteria through the den
IR R IT A T IO N A N D D E V IT A L IZ A T IO N
tinal tubules. The time required for an infected pulp to become completely de vitalized varies from a matter of days to years. Pulp degeneration may occur with
Cutting away too much tooth structure is a common fault, particularly in shoulder preparations. N o more tooth structure should be sacrificed than is actually necessary. The preparation of a tooth for a complete crown should be completed in one visit. Immediately after the im pression is completed the prepared tooth should be protected adequately from saliva and other irritating factors. Hypersensitiveness, especially at the cervical third of the crown, often results from failure to protect the exposed den tin. I f this condition is neglected, it may result in hyperemia which may develop into a true pulpitis. Normally, a simple and effective safeguard is to dry the tooth thoroughly, apply eugenol over the entire surface, and then volatilize the eugenol with warm air. T h e prepared tooth then should be covered completely with a temporary crown form lined with an effective agent; for example, zinc oxide and eugenol or surgical cement. A n opening should be made in the crown form on an appropriate surface to allow the excess liner to escape. Any temporary occlusal stress should be re lieved. Hypersensitiveness often can be relieved by the use of an astringent agent which will coagulate the dentinal fibers. Ammoniacal silver nitrate when applied to a deeply cut tooth surface is effective in relieving this condition, but its applica tion is limited to uses where discoloration is not objectionable. Whenever possible it is desirable to allow a few weeks to elapse until secondary dentin seals the injured tubules, and thus decreases sensitivity.
Deep-Seated Caries
• Before proceeding, the patient should be interrogated as to any history of pain. Clinical examination should include vitality and other tests, and periapical and bitewing roentgeno grams. In the presence of deep caries the pulp
out any clinical signs or symptoms. V i tality tests may indicate a vital pulp, al though the entire coronal portion of the pulp may be necrotic and the periapical roentgenographic evidence may be nega tive. All caries should be removed. In some instances after excavation the pulpal wall of the cavity will be close to the pulp. Sometimes the pulp is exposed directly; no attempt should be made to save such a pulp. W h en a tooth is amenable to endodontic treatment, such a procedure should be undertaken before noticeable inflammatory changes occur. A n aseptically filled pulp canal is more desirable than a diseased pulp. I f the tooth is to be retained, every effort should be made to disinfect the involved tubules after the exclusion of saliva. Caustic and irritating drugs should be avoided. Antiseptics having a seda tive quality combined with penetrating power are beneficial when applied to t h e ' exposed surface and volatilized with warm air; for example, beechwood creo sote or metacresyl acetate. A good cavity lining or varnish may then be applied to the exposed surface and allowed to set before it is covered with a thin cement. Another method is to insulate the floor of the cavity with a thick paste of zinc oxide and eugenol, covered by a layer of thin cement. Pulp tests should be made and roent genograms taken at intervals to deter mine the condition of the tooth. If increasing sensitivity results, the only re course is endodontic treatment or extrac tion.
Pulp Capping
• Clinical observations and histological investigations show that in adults most instances of vital pulp exposures followed by £ulp capping re
LIEBAN . . . VO LUM E 51, DECEMBER 1955 • 681
suit in inflammation of the pulp tissue with subsequent necrosis of the pulp, rather than in the formation of repara tive hard tissue. This has led to the gen eral belief that attempts to save adult pulps exposed by caries are contraindi cated.
Improper Adaption of Crown at Cervix • A ledge will occasion food impaction. If not corrected, such a condition will eventuate in a gingivitis and ultimately in alveolar resorption. Food debris will also cause décalcification and disintegra tion of the cementum. Dentin underlying cementum is permeable, and caries prog resses pulpward rapidly, frequently in volving the pulp. After the crown is adapted, roentgeno grams should be taken of the prepared tooth prior to cementation. This proce dure is important to ascertain whether the open end fits correctly at the cervix. A bitewing film, taken at the proper angle, is advocated in preference to the regular periapical film in order to avoid distortion. This should be supplemented by examination with an explorer.
Failure to Relieve Traumatic Occlusal Stress • Any complaint of soreness in a tooth should be investigated. Trauma may be traceable to a high spot on the incisal edge or occlusal surface. The entire occlusal surface may be involved. Occlusal correction involves some means of accurately recording and relieving such spots. Traumatic occlusion, if neg lected, will injure the periodontal tissues of the teeth. In some instances this in jury may cause circulatory changes re sulting in pulp hyperemia. Even when the occlusion is correct at the time of insertion of a crown or bridge, it may become faulty as time goes on. It is ad visable to recheck the occlusion occa sionally, even though the patient may not complain of discomfort. Gold crowns are less apt to break than porcelain crowns and may show wear
comparable to the wear of natural teeth, especially in mouths of patients who mas ticate forcefully.
Excessive Periodontal Involvement
• A careful diagnosis should always precede fixation of loose or drifting teeth. If the diagnosis is doubtful, a reputable perio dontist should be consulted. Resorption of the alveolar bone and widening of the periodontal membrane are manifested clinically by loosening of the teeth. Where a tooth has lost approximately more than one half of its bony support, the prognosis is not favorable. Some operators splint loosened teeth if there is extensive periodontal involve ment. T h e prognosis for such teeth may be definitely hopeless because of mobility and loss of supporting structures. If sev eral periodontally involved teeth are united by a fixed splint, and one of these teeth is not amenable to treatment, the splint is holding a tooth that should be extracted; retention of such a tooth will cause disease to spread to the adjacent teeth. It is illogical to attach bridgework to diseased teeth. The disease should be eradicated before the bridge is planned. Pulpitis may result from the extension of a periodontal pus pocket that invades the periapical area, a condition more prevalent in posterior teeth. Under these circumstances, endodontic treatment or the removal of the tooth is advocated.
Recession of the Gingiva • Patients’ teeth with exposed cementum are usually sen sitive to sweets, acids or thermal changes. Caries of cementum sometimes occurs when the gingiva has receded, exposing the cementum to saliva. Generally, there is a triangular depression bounded by the gingival margin, cementum and enamel. This may collect bacterial plaques, and caries of the cementum may develop. Later the dentin is invaded; however, there may be a gingival recession without the presence of caries. Plaques should be removed by scaling, and the patient
682 • THE JO U R N A L OF THE A M ER IC A N DENTAL ASSOCIATION
taught to avoid recurrences by proper home care. W hen caries has progressed to an appreciable extent the prognosis depends in a large measure on the preparation of the cavity and method of restoration that has been applied. T h e care given after wards by the patient is important. Neglect may cause hyperemia and produce par oxysms of pain. Irritation of the pulp may cause inflammation and subsequent devitalization.
Protection of the Prepared Tooth with a Temporary Crown Form • T o protect the anterior tooth temporarily, acrylic or celluloid crown forms are preferable esthetically. T o avoid disharmony in shade, the celluloid crown may be lined with synthetic cement. Before the cement sets, the adapted crown should be withdrawn, trimmed and lined with a protective medium, as with other types of tempo rary crowns. Alum inum or gold shell crowns generally are used only for pos terior teeth. These may be adapted di rectly to the prepared teeth or may be swedged on the dies of the prepared teeth. Temporary acrylic splints may be constructed to cover completely a num ber of adjacent prepared teeth. Regard' less of what type of temporary crown or splint is used, it should be lined with an effective obtundent.
Protection of Dentin Prior to Cementa tion of Permanent Crown • Vitality of a pulp may be impaired by the use of some irritating agent. Phosphoric acid in the cement may cause chemical irritation when the cement is forced into deeply cut, unprotected dentinal tubules. The prepared tooth when ready for cementa tion should be kept dry by using cotton rolls and the saliva ejector. The entire tooth surface should be dried with warm air, and any adherent temporary protec tion removed cautiously. Eugenol should be applied and volatilized with warm air. Ammoniacal silver nitrate precipitated
by eugenol may be used as an added precaution, where discoloration is not objectionable. As a final step in the prep aration for cementation, the tooth sur face should be dried thoroughly and coated with a cavity varnish. T h e cavity lining should be set prior to the actual cementation.
Cementation ' Cement mixed incorrectly may generate enough heat to cause pulpal irritation. A zinc cement that complies with American Dental Associa tion specifications is advisable. T h e direc tions of the manufacturer should be fol lowed. Inclusion of saliva beneath a crown or the imperceptible shifting of a crown during placement are causes of septic dentin. Excessive hammering in fitting, removing and cementing a crown is irritating to the pulp. Pressure of a cemented crown on a thin lamina of softened dentin covering the pulp may cause a pulpitis. T h e pulp is intolerant to pressure, and reacts vigorously when subjected to compression.
D IA G N O S IS O F O B S C U R E P A IN
A t times a patient who has undergone complete oral rehabilitation may com plain of a sore tooth or toothache. This may be mild or excruciating pain. The quality of pain as expressed by the pa tient is a relative term, and may be no guide to the intensity of the pain. Any complaint registered by the patient should be investigated carefully. Pain may be due to a temporoman dibular disturbance, neuralgia, traumatic occlusion, a periodontal condition, tooth surface sensitivity, pulp nodules, an in volved pulp or a combination of any of the aforementioned factors. Pain may be localized or referred. Until a pulp be comes involved, pain usually remains localized; with pulp involvement, re ferred pain may be pronounced. After the pulp has become devitalized, referred pain ceases, and any manifestation of
LIEBAN . . . VO LUM E 51, DECEMBER 1955 • 683
local pain is due to an involvement of the periodontal structures. It is not un usual to have pain referred to the region of another tooth. Each tooth has a sepa rate area of pain reference. Often the patient is unable to localize the source or even the nature of the pain. A t times the patient can point to the quadrant in which the pain occurs, but is unable to designate a particular tooth. Occasion ally, several teeth may be involved in different areas simultaneously.
C L IN IC A L PR O C E D U R E S
A correct diagnosis is contingent on a good subjective and objective examina tion with various clinical tests. The pa tient is requested to point out the painful tooth, and to describe the character of the pain, whether throbbing or dull, constant or intermittent. If intermittent, where, at what time and under what cir cumstances is it felt? Is it aggravated by thermal changes, or are such changes without influence in increasing or dimin ishing the pain? Is the pain associated with localized tenderness? For how long a period has the pain been experienced? This interrogation may be supplemented by a visual examination and clinical tests to substantiate a correct diagnosis. Judg ment will aid in interpreting diagnostic symptoms. If an acute dentoalveolar abscess is present, free drainage should be estab lished for the evacuation of pus and relief of pain. Attempts to establish suf ficient drainage through the pulp canal frequently are disappointing and are re sorted to only as temporary means of relief in instances where the tissue is not fluctuant. Where there is evidence of pointing on the surface, an incision is made in the soft tissue down to the bone, over the point of greatest tenderness. This is around the tooth apex. A n inci sion should be made only if the tissue is soft and fluctuant. A gauze strip is in serted for drainage. Penicillin, 500,000
units, is administered daily for three consecutive days. H om e care involves in termittent applications of ice packs over a moist cloth and frequent rinsing with a warm saline solution. After the acute symptoms have subsided, the tooth is treated as an infected pulpless tooth. Clinical procedures should include roentgenographic examination and ther mal, percussion, palpation, mobility and, if necessary, anesthesia tests. N o one method of pulp testing is entirely de pendable. Although it may not always be necessary to utilize all these tests for a given case, under certain circumstances it may be preferable to use two or more tests in order to arrive at a correct diag nosis.
Roentgenographic Examination • Stand ard intraoral films are used normally. In instances of vague pain, bitewing, oc clusal and extraoral films may be in cluded. T h e roentgenogram should be examined for a thickening or break in the line of the periodontal membrane at the tooth apex. The bone surrounding the apex should be examined for any periapical rarefaction, and the presence or absence of the lamina dura noted. Thermal Tests • For the heat test a small pellet of heated gutta-percha or the hot air blower should be applied labially or buccally, midway between the cervix and incisal or occlusal surface of the sus pected crowned tooth. H eat will occasion a quick painful response from a suppu rating pulp. For a simple cold test, a small pellet of cotton may be saturated with ethyl chloride, and applied as indi cated earlier. Sufficient time should be allowed for evaporation of the ethyl chloride to chill the tooth. Another method is to spray ethyl chloride directly on the questionable tooth after it has been isolated by the rubber dam. In interpreting responses to thermal changes, the dentist must be mindful of the fact that sometimes normal pulps
684 • THE JO U R N A L OF THE A M ER IC A N DENTAL ASSO CIATIO N
respond painfully, especially to cold. Hypersensitive dentin, hyperemic pulp or an acute pulpitis will react painfully to extreme cold. Teeth vary markedly in their tolerance to heat or cold. Adjacent teeth offer a control. T h e alternate appli cation of heat and cold may elicit a response, when either extreme alone may be ineffective. Nonvital teeth will not respond to either heat or cold. T h e electric pulp test for teeth with complete crowns is achieved by first making an opening of sufficient diameter through the crown to expose the dentin directly. T o avoid contact with the sur rounding area, the electrode should be coated with a nonconducting agent ex cept at the extreme tip. Chlorapercha may be used for this purpose.
Percussion Test
• In the percussion test the crown of the tooth is tapped m od erately with the blunt end of an instru ment. In the early stage of pulp inflam mation a tooth will not be sensitive to percussion. W hen periapical inflamma tion is present there will be a noticeable response. In a case of traumatic occlusion or a periodontal condition the tooth is usually sensitive to percussion. Adjacent teeth should be tapped also, so that the patient may distinguish any difference in discomfort. This test is not practical where two or more crowns are soldered together; tapping on one tooth will regis ter in all the other teeth throughout the segment.
Palpation Test
• In the palpation test slight pressure with a finger tip is applied
on the soft tissue over the root apex. Pain is felt when the periapical region is inflamed. In inflammatory conditions of the pulp which involve the periodon tal tissue, the presence of tenderness or pain to percussion or palpation is patho gnomonic.
Mobility Test
• The extent of mobility may be determined by moving a tooth labiolingually. T h e degree of abnormal
mobility will determine the extent of periodontal involvement.
Anesthesia Test
• Where pain is radiated and unilateral, the mandibular alveolar process may be anesthetized to determine the quadrant. If the pain subsides, it may be inferred that a mandibular tooth is involved. If the pain persists, it would indicate the involvement of a maxillary tooth. After this procedure, infiltration of each maxillary tooth in the quadrant may be done until the painful tooth is located. If bilateral diffused pain is present, the dentist may resort to a mandibular al veolar injection on both sides. Sufficient time must be allowed for the anesthesia to become effective on one side before the other side is anesthetized. If two or more mandibular teeth are present in a quadrant, in order to ascertain which tooth may be involved, the dentist must wait until the anesthetic effects have worn off before proceeding with other tests. T h e final diagnosis is based on the information obtained from a careful in terpretation of all the facts, and usually is a diagnosis by exclusion.
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