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Grey discolouration around occlusal amalgam restorations has been found to be useful for the diagnosis of secondary caries. The aim of the present in vitro study was to establish the validity of grey discolouration of buccal and lingual enamel next to the approximal amalgam of class II restorations for the diagnosis of secondary caries. One hundred buccal and lingual areas next to the approximal parts of a class II filling in molars and premolars were included in the study. Fifty-one areas showed grey discolouration. Validation was performed against radiographs of transverse sections. Both radiolucencies and radiopacities were scored as being caries. The results were: sensitivity 92%, specificity 55%, positive predictive value 22% and negative predictive value 98%. It was concluded that grey discolouration of the approximal walls next to class II amalgam fillings is not useful for the detection of secondary caries, but the absence of grey discolouration gives a good prediction for the absence of secondary caries. This is in contrast to grey discolouration around occlusal amalgam restorations, which was considered to be useful for the diagnosis of secondary caries.

Intra- and interexaminer reproducibility of clinical caries diagnoses was studied using 3 experienced dentists, who independently examined 20 patients twice at an interval of 2-6 weeks. The lesions were classified as one of the following four diagnoses: (1) initial active caries, (2) initial inactive caries, (3) manifest active caries, and (4) manifest inactive caries. For the various diagnoses, signs of cavitation, surface structure and discolouration were used. The reproducibility at a patient level was evaluated using intraclass correlation coefficients and at a surface level using kappa statistics. At a patient level, for the total number of lesions, the intraclass coefficients of correlation varied from 0.55 to 0.77. For the individual diagnoses, total manifest caries showed the highest coefficients of correlation, ranging from 0.73 to 0.92. At a tooth surface level, the kappa values varied from 0.29 to 0.61. The most common shift was that from any type of caries diagnosis to a diagnosis of a sound surface. There was little difference between the results for coronal and root caries and between initial and manifest lesions. Nor was there any difference for buccal + lingual surfaces only compared to all surfaces. Judging from the pattern of change in diagnosis between the repeated examinations, the main source of error seemed to be due to the fact that the lesions observed at one examination were overlooked at the other examination.

Tooth discoloration's may cause serious damage to the aesthetic appearance of the patients. These discoloration's can be treated in several ways but up to lately tooth structure had to be removed in an irreversible manner in order to provide sufficient bulk for the new restorative material. Nowadays thanks to the work of T. Croll and others a method has been established in a scientific way whereby tooth discoloration's confined to the outermost layer of enamel can be removed, through the application of an compound called PREMA which will simultaneous erode and abrade the enamel surface. If carefully selected the discoloration can be removed with only a limited loss of tooth structure. The authors describe the historical background of the method. Furthermore patient's selection, specific instruments and materials are described in detail. The clinical procedure is explained step by step, followed by a complete report of the effects of the procedure on the different tooth structures. Finally the long term results are discussed and the possibility to enhance the result by combining this method with home bleaching.

Regional odontodysplasia is an uncommon developmental dental disorder that may occasionally be accompanied by other abnormalities. A case is described in which the chief report was of a gingival enlargement arising in a female patient who also had dolichocephaly, thin calvarium, clinodactyly and transverse grooving of her fingernails, and a history of abnormal hair. Previously suggested etiologic factors and cases reported in association with other abnormalities are reviewed.

Early diagnosis of nursing-bottle caries is so difficult because its first stage is difficult to detect, and occurs at an age the child does not visit a dentist regularly. Also, the first stage does not appear alarming. If for the parent serious complaints from the child arise, irreversible defects already have developed. The developmental stages of nursing-bottle caries are clearly linked to the eruption pattern of the primary teeth. The maxillary primary incisors are affected first, followed by the maxillary first molars. In all stages, a stabilized condition, arrested caries, can occur, if circumstances change. A correct diagnosis of the etiology of caries in toddlers and preschoolers is mandatory as a basis for introducing proper preventive measures. Further study is mandatory to clarify the cause and effect of the disease-pattern.

A case of Y-shaped lower bilateral central incisors found in an 18-year-old Japanese man is reported. Each of the central incisors had an abnormally high cusp located at the labial surface. The cause of this malformation of the lower central incisors is obscure, but we suspect that it was due to hyperplasia of the labial surface of the central lobe of the incisor during tooth development.

The material comprised 140 extracted maxillary third molars. The central fossa area was examined with a stereomicroscope (SM) (x16) and macroscopically (M) under standardized conditions after cleaning and air-drying. Signs of caries were classified using a detailed scoring system involving 12 (SM) and 8 (M) classification criteria, ranging from 'sound' to 'cavitation with dentine involvement'. Six radiographic scores were used in the classification. Sections 250 microns in thickness were cut in buccolingual direction through the central fossa, and the fossa section with the most extensive stereomicroscopic changes was selected for histologic examination (x16). The histologic enamel and dentine changes were classified independently using 9 and 7 scores, respectively. The correlation between SM and the histologic enamel changes (HE scores) in terms of progressive demineralization and destruction were highly correlated (rs = 0.90). Dentinal changes were also highly correlated with enamel changes (rs = 0.85). The histologic classifications in conjunction with the macroscopical observations made it possible to demonstrate a clear relationship between the external degree of caries progression and the internal enamel and dentine reactions. The data did not support routine usage of radiographic examination for occlusal caries diagnosis.

Grey discolouration of the enamel around a filling and marginal fracture are often reasons to replace restorations due to suspicion of secondary caries. The aim of this study was to establish the validity of grey discolouration and marginal fracture for the diagnosis of caries at the enamel-dentine junction (EDJ) next to an amalgam filling. The occlusal surfaces of 161 extracted molars with occlusal amalgam fillings were photographed on colour slides, from which grey discolourations and marginal fracture were recorded. The size of the fracture was scored using a modified Mahler scale with six categories: score 1 = no marginal fracture (< 30 microns), score 6 = fracture width > 200 microns. Secondary caries at the EDJ was scored on radiographs of 700 micron sections of the molars. Both radiolucencies and radiopacities in dentine were scored as caries. The sensitivity of grey discolouration for detection of secondary caries was 50% and the specificity 91%. The positive and negative predictive values were 71 and 80%, respectively. Marginal fracture was evaluated at five different levels of severity. Although there was caries present more frequently at the EDJ under severely fractured margins, marginal fracture was found of little diagnostic value at all levels. Only marginal fracture at threshold level V provided a positive predictive value (50%), which was significantly higher than the caries prevalence (31%). It is concluded that width of marginal fracture, as defined by the Mahler scale, has hardly any value for the diagnosis of secondary caries. However, grey discolouration may be a useful diagnostic aid.

The aim of this in vitro study was to assess the staining of enamel in relation to fixation of luxated teeth. Color changes induced by chlorhexidine, red wine, tea, and coffee were detected with a Minolta Chroma Meter (CR-121) after extracted teeth were treated to simulate construction of dental splinting. L*a*b* color readings were made before and after 7 days of incubation in the above-mentioned media in teeth treated 1) by acid-etching, 2) by acid-etching followed by resin, 3) by resin and composite, 4) by Triad Gel, and 5) by Protemp. L* is an indicator of black (0) and white (100). The a* values relate to the red (+100)-green (-100) color axes, and the b* values to the yellow (+100) and blue (-100) axes. Untreated teeth served as controls. One-way analysis of variance of mean L* values revealed no statistically significant differences in treatment. Discoloration was observed in all teeth, including the control ones. However, Protemp yielded the largest changes in mean L* values. Analysis of variance of mean L* values revealed statistically significant differences between incubation liquids because no increase in staining of enamel was noted after 7 days' incubation in chlorhexidine. Red wine increased the mean L* values more than coffee or tea. Changes in a*b* readings were toward red (+a*) after incubation in red wine, except in the case of teeth treated with resin. The color of all such teeth changed more toward yellow (+b*), because the resin used was yellow.(ABSTRACT TRUNCATED AT 250 WORDS)

In recent literature some controversy has been reported regarding the prescription of bitewing radiography for caries diagnosis, particularly in children. While the low prevalence of caries justified the decision not to take radiographs, it has also been reported that the benefits of detecting slowly progressing, clinically undetectable lesions could outweigh the "costs" of radiography. It was the aim of this study to investigate whether specific risk factors could predict the presence of additional dentinal lesions (ADL) in the primary dentition on radiographs which could not be detected by visual inspection. Bitewing radiographs were taken in 182 children aged 5 yr. Risk factors for ADL were identified and appropriate rating scales were designed. Sensitivities, specificities and relative risks expressing the relation between scale values and ADL were computed for each of the risk factors and direct and stepwise discriminant analyses were performed. The results indicate that particularly the presence of lactobacilli and mutans streptococci in saliva and the detection of three or more discolored enamel lesions or dentinal lesions were good predictors of ADL. It is suggested that these risk factors be used in the timing of bitewing radiography in children with a primary dentition.

The purpose of this investigation was to study the relationship between low values of blood ionized calcium measured in the first days of life postpartum and the clinical and histologic appearance of enamel of primary teeth. Twenty-five healthy children selected on the basis of optimality with known blood values of ionized calcium from the first days of life participated in a dental examination at the age of 5 yr. Twenty-four of the children contributed one exfoliated tooth each, which was histologically examined. The infants had lower mean values of ionized blood calcium on days 1 and 3 than day 5 postpartum. Thirteen of the 25 children had enamel aberrations, mainly on one tooth each. The histologic examination showed normal overall enamel morphology. The neonatal line was present in all teeth, and these lines were mostly thin. The registered findings about the enamel morphology could not, in any case, be correlated with the measured values of neonatal blood ionized calcium.

An occlusal restoration is usually considered necessary when a lesion extends into the dentin. This study aimed to assess the relationship between the clinical appearance of occlusal caries and the lesion depth. Special attention was paid to differentiate the inner, partly demineralitzed layer of carious dentin that should be preserved from the outer carious layer that should be removed before placing a restoration. Fissures in extracted premolars and molars were classified clinically by the authors. The mean pairwise interobserver agreement, weighted Cohen's kappa (kappa), was 0.73, which indicated 'substantial agreement'. The depth of zones revealing softness by probing and/or discoloration was assessed on ground surfaces. Of the carious fissures that were scored sound by clinical examination (n = 17), 76% revealed enamel lesions on the ground surfaces. Of those occlusal surfaces with a discoloration only but no cavitation (n = 57), 13 showed dentin lesions, but only 5 of these revealed softness by probing. Of those lesions with very small cavitations (n = 60), 19 were confined to enamel, 41 showed dentin lesions and of these 32 revealed softness by probing. All but 1 of the lesions with small cavitations (n = 28) showed dentin involvement and all but 2 of these revealed softness. If cavitation in the occlusal lesion was used as a criterion for identifying dentin lesions with softness, the sensitivity and specificity values were 0.92 and 0.69, which means a relatively high frequency of overregistration.

The purpose of this study was to evaluate differences in periodontal and pulpal status, root length, and tooth alignment between contralateral maxillary lateral incisors, canines, and premolars in patients treated for unilateral impaction of maxillary canines. Clinical examinations were performed on 32 patients, average age 22 years 11 months and average posttreatment observation period 3 years 7 months. Probing attachment level was lower at the mesial and distal aspect of the previously impacted canine and at the distal aspect of the adjacent lateral incisor. Crestal bone height was lower at the mesial aspect of the previously impacted canine and at the distal aspect of the adjacent lateral incisor. The roots of the lateral incisors and premolars adjacent to the previously impacted canines were shorter. Pulpal obliteration was observed in six previously impacted canines (21%), and pulp necrosis in one previously impacted canine. The pulps of the remaining teeth appeared normal radiographically. A negative response to electric pulp testing was observed in eight previously impacted canines. Approximately 40% of the previously impacted canines exhibited noticeable relapse and were judged to be intruded, lingually displaced, mesially rotated, as well as discolored. Of the contralateral canines, 91% were normal in appearance. The previously impacted canine could be identified on posttreatment color slides in approximately 75% of the cases.

The aim of this study was to determine whether the use of a pre-brushing mouthwash Plax reduced extrinsic tooth-staining in vivo and in vitro. Firstly, in a double-blind placebo controlled cross-over study, 20 subjects with tooth staining used Plax or a placebo for 14-day periods separated by a 1-month wash-out period. The area of stain was assessed before and after each mouthwash had been used from clinical photographs. Secondly, extracted 3rd molar teeth were stained with tea and chlorhexidine. After exposure to either Plax or placebo, the teeth were brushed in a standardized manner. The area and intensity of stain were assessed before and after rinsing and brushing. Results of the study in vivo showed that the mean % stained area for any of the surfaces studied changed very little throughout the study. No statistically significant changes were detected (Student t-test, p > 0.05). Results of the study in vitro showed that the mean area of stain fell by 19% after exposure to Plax and by 17% after exposure to placebo. No statistically significant changes were detected (Student t-test, p > 0.05). There were also no significant changes in intensity (Wilcoxon signed rank sum test p > 0.1).

The effect of a degradable controlled release system containing cetylpyridinium chloride (CPC) on plaque accumulation and gingivitis was evaluated when applied on the anterior teeth of volunteers (16-17 years) over 4 weeks. At baseline, plaque index (PI) and gingival index (GI) of the Ramfjord teeth were measured in the experimental and placebo groups, including 23 and 21 participants respectively. Following scaling and root planning, the participants were instructed to brush, using one brush stroke, the film-forming solution on the buccal surface of the maxillary and mandibular incisors, 1 x a day before bedtime. The applied active solution contained 9 mg of CPC (approximately 80 mg of 11% CPC solution), while the placebo solution was identical in formation, but without the active agent. After 4 weeks, in the CPC-applied group, the recorded PI scores were 0.52 (+/- 0.56) in the anterior area and 1.31 (+/- 0.80) in the posterior area, whereas the corresponding areas in the placebo group reached 1.25 (+/- 0.74) and 1.51 (+/- 1.00), respectively. The PI = 0 frequency in the buccal anterior surfaces after 4 weeks was 54.6% (+/- 38.7%) in the experimental group as compared with 21.9% (+/- 29.0%) in the placebo group (p = 0.005). In contrast to the anterior teeth, there was no significant difference between groups with respect to the PI scores in the non-applied posterior teeth. It may be postulated that the impressive 58% inhibition of plaque accumulation at the site of application is the result of an increase of the substantivity of the CPC due to its incorporation in the film-forming degradable controlled release system.

While the phenomenon of pink teeth has been known since 1829, when it was first described by Bell, its application in forensic medicine has been limited. Recently, however, attention was again focused on pink teeth in legal cases. The medico-legal implication was the use of pink teeth as a possible means of evaluating the cause of death. Pink teeth can occur during life and postmortem. Except for very few and poorly documented exceptions, they develop earliest after 1 to 2 weeks postmortem. Their chemical analogy is seepage of hemoglobin or it's derivates into the dentinal tubules. Prerequisites are hyperemia/congestion and erythrocyte extravasation of the pulp capillaries, furthermore autolysis and a humid milieu. Therefore, they are most often associated with water immersion. The intensity of characteristics varies between different cases and also between different teeth in an individual case. Since the ante-mortem prerequisites are non-specific and can be replaced by certain postmortem conditions, there exist until now no specific correlation to the cause of death. The phenomenon is very often seen in victims of drowning where the head usually lies in a head-down position. From this it can be assumed that pink teeth even if not identical to postmortem lividity can, at least to some extent, be considered as analogous. Since, there is no obvious connection between the occurrence of pink teeth and the cause of death, it may be concluded that pink teeth are not pathognomonic for a specific cause of death and this is therefore an unspecific phenomenon.

Lactating dams with eight suckling pups were fed either a 20% protein diet as a control or experimentally a 20% protein diet supplemented with caffeine (2 mg/100g body weight) from the birth of the pups to day 22. At day 22, the pups from both groups were weaned and fed a cariogenic diet until day 50, when they were killed. Dental caries of the molars were scored from randomized mandibles. The enamel of the first molars in the caffeine group showed significantly higher caries scores than that of the controls. This appears to be the first unequivocal evidence that caffeine is a cariogenic agent when newborns are exposed to it during critical periods of tooth development. Therefore, the widespread human consumption of caffeine could be a threat to the healthy development of teeth.

Research and development has been aimed towards the development of toothpastes for oral hygiene and gingival health benefits. The most effective antiplaque agent to date, chlorhexidine, is difficult to formulate into active toothpaste products. Despite some encouraging findings for experimental chlorhexidine toothpastes, there are to date no commercially available products. Based on positive findings from an experimental gingivitis study, this investigation evaluated 2 chlorhexidine toothpastes, one with fluoride, as adjuncts to oral hygiene. The study was a double-blind controlled, parallel, balanced group design, extending over 6 months. A total of 297 volunteers commenced the study after screening for a minimum acceptance level of gingivitis. At baseline, 6, 12 and 24 weeks, stain, gingival, bleeding and plaque indices were recorded, together with a calculus index at 6, 12 and 24 weeks. After a baseline prophylaxis, volunteers used the allocated product 2 x per day, with no other oral hygiene instructions given. Plaque, gingival and bleeding scores improved in all 3 groups, but to an overall significantly greater extent in the active groups. However, staining and calculus indices were significantly increased in the active compared to the control group. If the local side-effects of chlorhexidine are considered to be acceptable, these chlorhexidine toothpastes could be recommended for the same clinical applications as other chlorhexidine products. The apparent compatibility of fluoride with chlorhexidine in the one product may be pertinent to caries prevention.

The aim of this study was to compare the accuracy of several common methods for the diagnosis of fissure caries. 63 human teeth without fillings and without any macroscopic carious cavitation but with different degrees of fissure discoloration and decalcification were selected from a pool. Dentists were asked to examine embedded teeth for fissure caries. The examination was done under standard conditions in a professional dental unit. The methods employed were: visual inspection (VI, n = 26 dentists), visual inspection with a magnifying glass (2x; VIM; n = 26), conventional bite-wing radiography (BW; n = 24), visual inspection combined with conventional bite-wing radiography (VI + BW; n = 10), and visual inspection combined with light pressure probing (VI + P; n = 23 dentists). In order to measure the reproducibility, VI and VI + BW were repeated. After the last inspection, the teeth were histologically prepared, serially sectioned perpendicular to the occlusal surface, and diagnosed for the presence of caries. The agreement between histological and clinical diagnosis was assessed. Specificities and sensitivities were: VI = 93 and 12%, VIM = 89 and 20%, BW = 83 and 45%, VI + BW = 87 and 49%, and VI + P = 93 and 14%, respectively. The following likelihood ratios were found: VI = 1.84, VIM = 1.86, BW = 2.6, VI + BW = 3.85, and VI + P = 2.05. It was concluded that the rather low sensitivity especially for VI and VI + P may lead to a significant number of teeth with dentinal caries being undetected.(ABSTRACT TRUNCATED AT 250 WORDS)

A clinical study determined the whitening effect of a 10 percent carbamide peroxide gel on the teeth of 10 subjects. Histological evaluation of the effect of this agent on human tooth pulps and hamster cheek pouch tissues was also undertaken. The gel provided a modest, but unpredictable, whitening of discoloured teeth. A localised mild to moderate inflammatory response was found in some of the pulps of teeth that had been bleached. No soft-tissue changes were observed in the hamster cheek pouches.

Chlorhexidine and fluoride have valuable preventive roles in dental and oral diseases. There is also evidence that in caries prevention, together, they provide additive benefits. However, combined chlorhexidine/fluoride formulations have rarely been evaluated. The aim of this study was to determine whether a 0.12% chlorhexidine, 100 ppm F- mouthrinse provided adjunctive oral hygiene benefits compared to a minus active control rinse. The study was a randomised double-blind parallel design involving 102 subjects of whom 99 completed the 6 week experimental period. Subjects rinsed 2x per day for 1 min with 15 ml of the allocated rinse. Normal toothbrushing procedures were maintained throughout the study. At 6 weeks, plaque and gingivitis scores were significantly lower and the incremental reduction significantly larger in the active rinse group. However, as expected, toothstaining was significantly increased with the active rinse. It is apparent that this chlorhexidine/fluoride rinse could be used in those regimens recommended for other chlorhexidine formulations. The value of the formulation in caries prevention would seem worthy of further investigation.

The operative management of primary and secondary caries assumes that all discoloured tissue at the enamel-dentine junction (EDJ) represents active disease and this is removed to arrest the carious process. This study aims to establish clinical criteria to differentiate between active and arrested caries at the EDJ using microbiological assessment of dentine samples to verify its clinical status. Radiographs were available for posterior teeth. Cavities (n = 205) were prepared under rubber dam. After gaining access, areas of the EDJ were chosen and assessments made of consistency (soft, medium, hard), colour (dark brown, mid-brown, pale) and moisture content (wet, dry). Dentine was removed by using a No. 3 round burr and placed in 1 ml of bacteriological culture broth. This sampling procedure was repeated at the same site once during cavity preparation and again when the cavity was judged as fully prepared. Samples were vortexed, diluted and cultured to give viable counts of the total anaerobic microflora, mutans streptococci and lactobacilli; viable counts were expressed as log10 (CFU per sample +1). Results showed no significant differences between the microflora of primary and secondary caries. The number of bacteria recovered diminished significantly as cavities were completed. Initial samples from soft and wet lesions harboured significantly more bacteria, lactobacilli and mutans streptococci than samples from medium, hard or dry lesions. Lesions visible on radiographs harboured more bacteria, including lactobacilli and mutans streptococci, while dentine colour was not discriminatory.(ABSTRACT TRUNCATED AT 250 WORDS)

The purpose of this study was to determine if the extrinsic dental staining associated with the use of chlorhexidine gluconate (CHX) mouthrinse could be prevented or controlled by the patient with the use of toothpicks. 25 subjects received a prophylaxis to establish a stain-free baseline and were then randomly assigned a control and experimental side of the mouth. The rinsing regimen was 1/2 oz of 0.12% CHX mouthrinse 2x a day for 3 months. Subjects self-examined daily for the appearance of stain. Where stain was visible, a toothpick was used to 'rub it away' on the distolabial, labial and mesiolabial surfaces of the experimental side only. The rubbing action was similar to the use of an eraser to remove a pencil mark from paper. The amount and intensity of stain was photographed and graded by a blinded examiner after 2 weeks, 1, 2 and 3 months. Subjects kept calendars to encourage and document compliance. When analyzed across time, teeth and surfaces, there was a statistically significant difference in stain between the control and experimental sides for stain amount, intensity, and for a composite of amount/intensity. Clinical differences were slight. The study indicates that the use of a simple toothpicking technique can affect chlorhexidine stain.

One hundred extracted molar teeth with discoloured fissures but without any visible carious cavitation were selected from a large supply, using standardized criteria. The teeth were mounted, placed on a mechanical balance, and probed with a force of 500 g in every fissure, at as many places as possible. Every time the probe was found to stick, the spot was marked. After probing colour slides were made of the occlusal faces. Subsequently, the crowns were embedded in epoxy resin. 700 microns thick sections were cut in a facial-lingual direction with a diamond wheel. From the sections X-rays were taken which were scored as follows: a measuring grid was placed on the X-ray image of a section, and the caries score (0-4) for every millimetre was determined. By scoring every section of a tooth in this way, an overview was obtained of the location of all caries lesions in the occlusal surface. By comparing this overview with the colour slide of the tooth, the relationship between the sticky spots and the lesions was visualized. The results indicate that only 24% of the caries lesions were discovered by probing for stickiness (low sensitivity), but that the probe seldom stuck in a sound fissure (high specificity, > 99%). Probing proved to be unreliable for the diagnosis of fissure caries.

Mg-containing calcium phosphate crystals including pseudocuboidal, rhombohedral shapes and groupings of quadrangular blades cubically arranged were found in human tooth enamel by scanning electron microscopy and by electron probe microanalysis. In caries-free old enamel, these hexahedrally based crystals measuring 0.5-2.5 microns in length were observed in some crevices of tufts and lamellae. The crystals were rarely seen in the inner crevices of caries-free exfoliated deciduous enamel and none could be seen in sound young enamel. In brown-coloured old enamel possessing arrested caries with lamellae, some of the lamellae contained crystals measuring 0.1-1.5 mu in length adjacent to half-dissolved prisms. These crystals, identified as Mg-containing whitlockite, will grow during a long period after eruption of the tooth or during the enamel caries process.

Many clinicians take for granted that occlusal caries which is just visible as a cavity is extended (deep) into the dentine. This study was aimed at quantifying this opinion. The study was carried out with 60 molars containing small but visible occlusal cavities. After taking bite-wing radiographs the crowns were separated from the roots and embedded. 700-microns sections were cut and glued on plastic sheets. X-ray pictures were taken of the sections which were scored by independent examiners. The bite-wings provided inaccurate estimates of the extent of caries. Radiographs of the sections revealed that about 25% of the molars had caries which reached just to the dentino-enamel junction, while the remaining 75% showed caries extending far into the dentine.

At general dental practices in Scotland 211 children between the ages of 5 and 15 years were examined by 1 observer. A comparison of the status of 1,468 permanent and 756 primary posterior approximal surfaces was made on the basis of their appearance on posterior bite-wing radiographs and the findings of a direct in vivo visual examination, made after temporary tooth separation had been achieved over 1 week using elastomeric separation. For permanent tooth surfaces, 0% of radiolucencies in the outer half of enamel, 10.5% in the inner half of enamel, 40.9% extending to the outer half of dentine, and 100% extending to the inner half of the dentine were found clinically to be cavitated. The analogous results for primary teeth were that 2.0, 2.9, 28.3, and 95.5%, respectively, of radiolucencies appeared to be cavitated. Although further research with larger numbers of permanent teeth is indicated, these results may contribute to a re-evaluation of the optimal threshold for restorative intervention at approximal sites. Greater numbers of approximal radiolucencies and carious lesions (p less than 0.001) were found in those surfaces which initially had a normal anatomical contact when compared to those which did not.

The histopathology of arrested root caries lesions was examined in extracted human teeth. The main structural characteristics of arrested lesions were the completely mineralized surface area and the formation of a distinct sclerosis of the dentinal tubules. Intertubular dentin was, with the exception of the dentinal tubules, fully mineralized up to the surface. Dentinal tubules near the surface were either filled with ghosts of microorganisms or with crystals of different shapes. Sclerosis of the dentinal tubules was characterized by the presence of three different patterns of intratubular mineralization that occur in distinct regions of the zone of tubular sclerosis. The patterns were distinguishable by the type of crystals and their association with organic structures such as collagenous fibrils or odontoblast processes. It is suggested that arrested lesions are based on (1) the formation of an inner barrier that interrupts the diffusion of substrata from the pulp to invaded bacteria, (2) the formation of an outer barrier by a compact, highly mineralized surface region which blocks the diffusion of products of bacterial metabolism into dentin, and (3) an area of mineralization which extends from the outer barrier toward the root canal within demineralized dentin. The present study demonstrates the considerable potential of caries lesions in dentin to become arrested, and subsequently partially remineralized. These phenomena seem to depend on the severity of an active lesion and its location on the root surface. This should be taken into account when diagnosing root caries lesions. The potential of root caries lesions to become arrested indicates that the treatment concept of active root caries lesions should be reconsidered.

Extrinsic brown tooth discolorations are frequently detected in connection with antibacterial agents used for chemical plaque control. The present investigation confirmed the staining ability of an antibacterial quarternary ammonium salt, benzethoniumchloride, used as a 2% additive to a dentifrice. A weak chelator did not alter the discoloration tendency. Extrinsic discoloration was evaluated both by direct inspection, from color photographs and by using a microphotometric technique. The discoloration tendency was well demonstrated by all three techniques. Evaluation from the color photographs, however, may be preferable in epidemiological surveys while the microphotometric technique may possess certain advantages in detailed experimental discoloration studies.

Loss of enamel and a deep black stain of the teeth in a 40-year-old diabetic patient are strongly suggested to be caused by the daily consumption of a cheap white wine and, possibly, by the chewing of cayenne. The wine proved to be rather acid, thereby promoting abrasion as a result of gnashing, and to contain a high concentration of tannin. The exact role of the tannins is described.

Tooth staining with the use of chlorhexidine preparations is the major problem of long term application. Evidence suggests that the staining arises from a cationic/anionic interacation of chlorhexidine with components of certain dietary materials. The purpose of this in vitro study was to compare visually the development of tea and coffee staining on acrylic and tooth specimens treated with chlorhexidine and to follow the development of tea staining on perspex by light microscopy and color television image analysis. All specimens were maintained in their respective beverage for 5 days with test specimens removed three times a day and placed for 2 minutes in an 0.2% chlorhexidine solution. Both test tooth and acrylic specimens showed comparably and markedly increased staining by the beverages compared with control specimens. Color television image analysis of test specimens demonstrated more marked and rapid development of tea staining when studied on a daily basis. Microscopic examination revealed the staining to be made up of small particles of material which increased in size and coalesced with time. Again, marked differences were apparent in the stain on test and control specimens. The results of this in vitro method provided further evidence for a dietary aetiology to chlorhexidine staining and were consistent with clinical findings. Such a method may be useful to assess staining arising from the use of other anti-plaque agents.

The aim of this study was to produce pink teeth experimentally with cadaver blood and to correlate the time sequence of the coloration with the pattern of hemolysis of the blood. The blood from 7 cadavers (postmortem period 8-58 h) was used to stain 7 groups of 14 teeth each. All the teeth were divided longitudinally and one half received blood which contained a piece of skin (to imitate pulpal autolysis) and the other half cadaver blood only. Circumpulpal discoloration commenced on the sixth day postmortem and increased to 18 days. At 6 days, hemolysis was evident histologically and the separation between plasma and blood cells had disappeared in centrifuged blood. No difference was noticed between the blood with and without skin. It is concluded that pink staining of teeth can only occur after hemolysis and that discoloration becomes obvious macroscopically at about 6 days.

The appearance of hard human tissue after thermal damage permits certain conclusions to be drawn with regard to fire parameters. In addition to morphological destruction, the change in color of dental tissues like enamel, dentine, and cement is also important. We studied teeth extracted from 330 human males and females under well-defined time and temperature conditions. Using the DIN and RAL color indexes, the color phenomenon was evaluated on the basis of the amount of glowing obtained when the teeth were heated. It is easiest to determine the color change in cement, as no calculus or hindering plaques are on the root surface. In addition to this, destruction of the tooth root takes place only during extreme combustion conditions. Determining the dentine color is more difficult and is possible only after the enamel splits. Also, the different dentine thicknesses hinders the observation of color. When the enamel was tested, it was found that the differences in color caused by high temperatures are unimportant. Moreover, the enamel burst into small particles. The effect we observed regarding the anthracite lustre using low temperatures was typical, and the best results were obtained in dental roots with eight color scales. All three dental hard tissues have in common that the variations in color appear regularly and successively according to ascending temperature or duration of time: natural dental color, black, brown, blue, grey, white, and pink. In these processes, the temperature and combustion time are inversely proportional to the velocity of color change. The literature is discussed that deals with temperature- and time-dependent color phenomena of dental hard tissues destroyed as a result of thermal damage.

Oral changes related to the occupation of glassblowing have been examined in 74 Danish glassblowers, consisting of 44 active glassblowers (Group 1) and 30 past glassblowers (Group 2). In addition, 15 non-glassblowers (Group 3) were examined. All three groups worked in the same department of mouth-blown glassware in Holmegaard's Glassworks. White patches of the buccal mucosa occurred in 23% of active glassblowers, but did not occur among past or non-glassblowers. Histologically, the white lesions revealed morsicatio buccarum-like changes. The lesions are reversible and should be distinguished from leukoplakias. The term "glassblower's white patch" is suggested. Furthermore black discolorations of vermillion border and front teeth occured in 30% and 62%, respectively, of active glassblowers. Tooth fractures, mostly enamel fractures, caused by the blowpipe were found in 43% of active glassblowers and 19% of past glassblowers.

Various treatment variables associated with a standard bleaching technique were systematically recorded in 53 individuals exhibiting intrinsic discoloration of permanent teeth. These variables (predictors) included: (1) etiology (fluoride or tetracycline); (2) age of the patient; (3) the presented color of the stain; (4) the intensity of that color; (5) a long versus short bleaching time technique; and (6) the number of bleaching sessions. These were assessed as to their relationship with the results of treatment (dependent variable). The findings of a multiple regression analysis revealed that the contributions of the individual predictors were significantly different between those stains caused by tetracycline ingestion (N = 27) and those stains due to fluoride ingestion (N = 20). The analysis also revealed that those variables contributing to a significant proportion of the variance in results of treatment when tetracycline was the cause were: (1) the color of the stain and (2) the number of bleaching sessions. When fluoride was apparently the causal agent: (1) the bleaching time technique; (2) age of the patient; (3) color of the stain; and (4) the number of bleaching sessions contributed to a significant proportion of the variance in the results of treatment.

The use of tetracycline drugs in young children can cause discoloration of bone and dental hard tissues. Results show that more than half of patients treated were satisfied with their tooth color after bleaching.

The deciduous and permanent teeth in some patients with osteogenesis imperfecta syndromes are blue or brown and opalescent. As shown by radiologic examination, the pulp chambers and root canals are completely or partially obliterated by abnormal dentin. The junctions between the crowns and roots are more constricted than normal. Deciduous opalescent teeth lose their enamel readily and wear more easily than normal. Unusual wear does not occur as frequently in permanent opalescent teeth as in deciduous teeth. No relationship has been shown between the number of fractures or deformity and the degree to which the teeth are affected. In contrast, other patients with osteogenesis imperfecta have normal teeth. These clinical differences in the dentitions support the concept of genetic heterogeneity is osteogenesis imperfecta and provide information useful in genetic counseling. The differential diagnosis of opalescent teeth in osteogenesis imperfecta is not difficult provided that detailed clinical and radiologic examinations of the dentition are performed. Patients with osteogenesis imperfecta and opalescent teeth should be evaluated as soon as the deciduous teeth erupt, so that an attempt can be made to prevent loss of tooth structure. However, methods of dental care in osteogenesis imperfecta are not well delineated and deserve further study.

Classification by origin and structure of the many different coatings which occur on the surfaces of teeth and artificial surfaces exposed to the oral environment necessitate a revision of the terminology used to describe these coatings. Numerous gaps still exist in our understanding of the origin, morphological structure and chemical composition of many of these structures, notably the ones in the "acquired" category. The proposed classification of surface coatings, although not definitive, may provide a more accurate categorization of these structures in the light of contemporary knowledge.

Disagreement exists amongst investigators as to whether or not teeth should be dried before they are examined for developmental defects of enamel. To determine if results are affected by drying of the teeth, 91 extracted premolars and first permanent molars were examined first wet, and then again 1 week later after drying. Following removal of loose debris with an explorer, the enamel defects that were present were categorised according to a modified version of the FDI (DDE) Index. The drying of the surface of the tooth by compressed air allowed a more detailed and precise examination to be performed because the nature and extent of the defects were easier to see. This resulted in diffuse opacities being diagnosed in 144 (52.7 percent) of the tooth regions when the teeth were wet, and 161 (60.0 percent) after drying. The level of reproducibility of diagnosis was higher under dry conditions. It was easier to determine the colour of the teeth using a colour guide than without this assistance. These findings indicate that it is important that investigators performing clinical surveys on the prevalence of defects of enamel should clearly specify whether the teeth were examined wet or dry.

Toothpaste abrasivity should be sufficiently high to give effective cleaning without causing mechanical damage to tooth tissue. A clinical trial carried out to measure the cleaning power of calcium carbonate toothpastes of different abrasivity is described; cleaning power is then related to in vitro dentine abrasivity measurements. These findings are used to derive an expression specifying the toothpaste cleaning power which ensures that a chosen low and cosmetically acceptable level of stain is not exceeded providing a consistent daily brushing routine is adhered to.

The prevalence of enamel defects in Hong Kong was determined using a randomly selected group of 12-year-olds (N = 1,069). The most common defects were enamel opacities, which occurred in 99.6% of the Chinese children, with 63.4% of them having more than 20 teeth affected. Almost 17% of the Chinese children had disfiguring enamel discoloration, but only one of the non-Chinese children had this defect. The high prevalence of enamel defects may be related to the high frequency of use of tetracycline, metabolic disturbances, and a greater-than-optimal intake of dietary fluoride.