Journal of Clinical Periodontology: 1979: 6: 98-105 Key words: Amalgam restorations - ptaque control - Periodonia! health. Accepted for publication: May 17, 1978.

Amalgam restorations, plaque removal and periodontal health I. GORZQI, H . N . NEWMAN- AND J. D. STRAHAN^

^University Medical School, Szeged, Hungary ^Institute of Dental Surgery, Eastman Dental Hospital, London, England Abstract. A total of 156 approximal subgingival amalgam overhanging margins were ass^sed in the buccai segments of 13 patients for plaque accumulation, gingiva! infiammation, pocket depth and gingival shrinkage. Recordings were made immediately before and 2, 4 and 8 weeks following scaling, removal of overhangs, and oral hygiene instruction. Surfaces with overhangs were compared with control surfaces, which were either intact or contained supragingival amalgams. Initially it was found that gingival inflammation and pocket depth were more extensive adjacent to subgingival amalgam overhangs than to sound teeth or those with supragingivally located amalgams. This appeared to he due to preferential plaque accumulation in relation to subgingival overhangs. For all parameters compared, differences apparent at the baseline had disappeared by the end of the 8-week study period. Contouring of defective subgingival restorations, followed by effective scaling and oral hygiene instruction produced approximately 1 mm of gingival shrinkage, sufficient in most cases to produce clinical gingival health. Of the 156 subgingival fillings 83 (53 %) became supragingival and 43 (28 %) reached the gingival crest by the end of the 8-week study period.

Several studies indicate that restorations placed subgingivaliy, particularly those with defective margins, produce a level of gingivitis more severe than in relation to comparable unrestored teeth (Renggli & Regolati 1972, Mormann et al. 1974, Leon 1976). Other reports suggest the importance of placing the apical limit of smooth surface restorations coronal to the gingival margin (Mitchell 1959, Waerhaug 1960, Hazen & Oshorne 1967, Silness 1970, Zeines 1971, Valderhaug & Birkeland 1976, Valderhaug & Hel0e 1977). Therefore it seemed desirable to observe the effect of removal of overhanging subgingival margins, in conjunction with plaque control, on gingival health.

Material and Methods Patients were selected for study, having been referred for periodontal treatment to the Eastman Dental Hospital. All had chronic gingivitis or early periodontitis and several Class II amalgam restorations in posterior teeth. Patients with known systemic disease, taking drugs or wearing oral prostheses were excluded. None of the patients had received oral hygiene instruction prior to the first appointment. All approximal premolar and molar dento-gingival units containing amalgams, (excluding third molars) were examined clinically and radiographically. Prior to commencement bitewing films were used to detect amalgams

0303-6979/79/020098-08$02.50/0 © 1979 Munksgaard, Copenhagen

AMALGAM FILLINGS AND PERIODONTAL HEALTH

with overhanging margins. Surfaces with overhangs were compared with control surfaces which were either intact or contained supragingival amalgams. Teeth with nonamaigam restorations were omitted from the study. Control surfaces were either contralateral in the same mouth as the test surfaces or ipsilateral or contralateral in different mouths.

99

Removal of Overhangs Overhangs were removed on first and second visits with conventional hurs and with an ultrasonic sealer (Cavitron 700®, Dentsply International Inc., U.S.A., tips PI, P3, PIO). The removal of overhangs was considered successful when tbere was no palpable transition between tooth and restoration surfaces as tested with a Cross calculus probe. Those margins whieh could not be trimmed satisfactorily were excluded from the study.

Oral Hygiene Instruction At the first appointment each patient had at least 20 min oral hygiene instruction consisting of motivation, education on the nature of periodontal disease and instruction in toothbrushing and interdental cleansing. Patients were given two nylon brushes (Toothguard® 41, Prevdent Ltd., England) and Ceplac® tablets (Berk, England). The use of other aids such as Interdens® (Standard, Nicholas Proprietary Ltd., Australia) or Interspace® brush (Halex, England) was encouraged if considered necessary. Disclosing of plaque and oral hygiene instruction were carried out at all appointments. A frequency of twice daily for toothbrushing and one for other aids was recommended.

Examination Technique and Recording Sequence Each segment was dried with air before recordings were taken in the following order: pocket depth measurements, gingival inflammation (Sulcus Bleeding Index, SBl, Miihlemann & Son 1971) Plaque Index (PU, Silness & Loe 1964) and measurement of shrinkage (distance between restoration and gingival margin). A Cross calculus probe marked with the same graduations as a Williams pocket measuring probe was used for measurements. Distances were recorded to the nearest half millimeter. To avoid problems in standardization, the same probe

Table 1. Sulcus Bleeding Index for test and control surfaces Blutungsindex (Gingivalsaum) bei Test- und Kontrollfldchen Indice de saignement du sillon gingivo-dentaire: surfaces experimentales et temoins Student's Significance t-test level

Control surfaces

Test surfaces Weeks

Q 2 4 •

8

n

X

SE

n

X

SE

t

P

156 156 156 156

1.82 0.89 0.76 0.32

0.07 0.09 0.08 0.05

226 226 226 226

1.14 0.65 0,51 0.25

0.06 0.06 0.05 0.03

6.98 2.20 2.51 1.09

P < 0.001 P < 0.01 P < 0.01 NS

Weeks (Wochen, semaines), test surface (Testflachen, surfaces experimentales), control surfaces (Kontrollfldchen, surfaces temoins), significance level (Signifikanzniveau, niveau de signification).

GORZO, NEWMAN AND STRAHAN

100

Table 2. Plaque Index for test and control surfaces Plaque-Index bei Test- und Kontrollfldchen Indice de Plaque: surfaces experimentales et temoins Test surfaces

Student's Significance t-test level

Control surfaces

Weeks

0 % 4 8

n

X

SE

n

X

SE

156 156 156 156

2.10 0.92 0.79 0.44

0.05 0.07 0.08 0.04

226 226 226 226

1.62 0.72 0.63 0.46

0.06 0.05 0.04

was used for all measurements. Only those restorations where there was a definite interruption in a coronal movement of the prohe over the tooth-amalgam interface were considered as possessing overhanging margins.

0.05 •

t

P

5.74 2.06 1.61 0.30

P < 0.001 P < 0.05 NS NS

male, age range 21-52; mean 31.7 years) examined in the trial. Of a possible 208 teeth, 199 were present, of which one was crowned. Of the 396 approximal surfaces thus available for study, 370 had subgingival overhanging margins; 60 had apical margins located at or coronal to the gingival margin; 166 surfaces were sound. Of the 170 test surfaces, 14 were omitted from the study because overhang removal was inadequate. The 60 supragingiva! restorations and 166 sound surfaces were initially treated separately, but subsequently pooled to form a control group, as no significant difference was found between them for any of the parameters investigated. Only 112 of the overhangs were detected radiographically, compared with an original total of 170 detected with a Cross prohe.

Statistical Analysis The Student's t-test (Armitage 1971) was used to evaluate the significance of parametric (pocket depth, gingival shrinkage) and nonparametric (SBI, PII) data. P values greater than 0.05 were regarded as insignificant (NS).

Results

There were 13 patients (10 female, three

Table 3. Pocket depth for test and control surfaces Taschentiefen bei Test- und Kontrollfldchen Profondeur des culs-de-sac: surfaces experimentales et temoins Test surfaces

Student's Significance t-test level

Control surfaces

Weeks

0 2 4 8

n

X

SE

n

X

SE

t

P

156 156 156 156

3.39 2.66 2.64 2.24

0.11 0.10 0.10 0.07

226 226 226 226

2.72 2.39 2.28 2.10

0.07 0.08 0.06 0.05

4.86 1.95 2.88 1.54

P < 0.001 P < 0.05 P < 0.01 NS

AMALGAM FILLINGS AND PERIODONTAL HEALTH

101

Table 4. Gingival shrinkage Gingivale Rezession Retraction gingivale (distance entre I'obturation et le rebord gingival)

Weeks

0 2 4 8

Student's t-test

Gingiva! shrinkage

156 156 156 156

-0.68 -0.31 + 0.06 + 0.41

SE

dx

SE

t

0.02 O.OS 0.08 0.07

0.38

0.11

2.80

0.37

0.10

4.60

0.35

0.12

3.50

Sulcus Bleeding Index Table I shows tbat there was a higber SBl (1.82 ± 0.07) adjacent to restored surfaces with subgingival overhangs than in the control group (1.14 + 0.06, P < 0.001). This difference was statistically significant up to the end of the fourth week. Improvement within the period of study was highly signifieant (P < 0.001) for both test and control sides. Plaque Index Table 2 shows that before treatment the PH scores for all test surfaces (2.10 ± 0.05) were significantly higher than the controls (1.62 ± 0.05, P < 0.05). The difference between baseline and final scores was highiy significant for both sides (P < 0.001).

Gingival Shrinkage At the baseline (Table 4) all 156 fillings were located apical to the gingival crest

P < 0.01 P < 0.001 P < 0.001

(0.68 ± 0.06 mm). Shrinkage was more marked during the first 4 weeks (0.75 mm) than during the second 4 weeks (0.35 mm). Relation of Gingival Margin to Restorations Table 5 shows that of the 156 fillings, 67

Table 5. Relation of restorations to gingival margin Lagebeziehungen zwischen Fiillungen und Gingivalsaum Rapport entre les obturations et le rebord gingival Relation of fillings to gingival crest Weeks

0

Pocket Depth Pocket depth (Table 3) differed significantly up to 4 weeks from the basehne when test and control surfaces were compared (baseline: P < 0.001, 2 weeks: P < 0.05, 4 weeks: P < 0.01). The difference was not significant after 8 weeks (P > 0.05). Reduction for both groups was highly significant ( P < 0.001).

Significance within procedure

Apicai to margin At margin 156

100% 2 4 S

Coronal to margin

89 57% 64 41% 30 19%

31 20% 38 24% 43 28%

36 23% 54 35% S3 53%

Relation of fillings to gingival crest (Lagebeziehungen zwischen Fullungen und Gingivalsaum, rapport etitre les obturations et la crete gingivale), apical to margin (Apikal des Gingivalsaumes, apical par rappori au rebord), at margin (Am Gingivalsaum, au niveau du rebord), coronal to margin (Koronal vom Gingivalsautn, coronaire par rapport au rebord).

GORZO, NEWMAN AND STRAHAN Vi-ere relocated supragingivally or at the gingival crest after only 2 v^-eeks. At the end of the study, only 30 (19 %) were still subgingival. Discussion

The results suggest that compatible and sensitive index systems were chosen because they appeared to correlate to one another throughout the assessment period. A difficulty arose in the scoring of the Sulcus Bleeding Index when a bleeding point did not appear after gentle probing. In such cases, the suggested 30 seconds waiting time had to be applied. This occurred noticeably at the end of the study. Changes in color or texture (edema) were assessed without difficulty. The likelihood of error was reduced by assigning the lower of the two possible scores to any doubtful site. The SBI appeared to correlate satisfactorily with the ciinicai features of inflammation. The method was, in addition, sensitive enough to detect bleeding points even in those instances where there were no overt signs of inflammation. The difference in gingival inflammation between subgingivally filled and control sides was highly significant at baseline, before any treatment or instruction had been given; this notwithstanding the presence in the control group of 60 filled surfaces located at or coronal to the gingival crest. This finding is in agreement with those of Renggli & Regolati (1972), Mormann et al. (1974) and Leon (1976) but not with those of Gilmore & Sheiham (1971) who found no difference between filled and control sides. Total plaque assessment was impracticable in relation to the margins of fillings, especially those with subgingival overhangs. Even stained plaque was almost invisible on the surface of amalgam as compared with the tooth surface. On rough amalgam surfaces the crossing probe did not leave a discrete trail as on sound enamel.

Plaque Index (PU) values followed a more or less similar pattern to those of the SBI, although there was a significant difference only up to 2 weeks from baseline, whereas SBI showed a significant difference at the 4-week point. Over the 8-week period, PU, as SBI, was reduced, improvement being most marked on the test side. This was to be expected, since the baseline values for both indices were higher on the test side. Similar findings were obtained by Renggli & Regolati (1972) and Leon (1976). Renggli & Regolati (1972) found higher plaque scores for filled surfaces, independent of whether the restoration margins were supra- or subgingival. Leon (1976) reported that the plaque score of teeth with amalgam restorations was significantly lower than that for unrestored teeth. No significant difference was found by her when unrestored teeth were compared with restored surfaces with ledges or deficiencies. As regards measurement of pocket depth, it was usually necessary at the first appointment to remove gross calculus or overhangs to gain access to the base of tbe pocket. During' the resolution phase recording became increasingly difficult due to healing and tightening of the gingiva around the tooth. These factors might have led to an underestimation of pocket depth (Armitage et al. 1977). The results did, in fact, show a significant difference between test and control sides at baseline and significant improvement during the study on both sides in spite of this possible underestimation. Comparison of pocket depth with results from other studies is difficult because of limited data in the literature. Leon (1976) found a significant difference when comparison was made hetween pocket depth adjacent to intact approximal surfaces and those with restorations with ledges or deficiencies. This is in agreement with the baseline findings of the present study. A mean of 1.1 mm gingival shrinkage

AMALGAM FILLINGS AND PERIODONTAL HEALTH was gained during the 8-week period. The reduction was greater during the first 4 weeks and by the end of the study, of the 156 subgingivally located filhngs 83 (53 %) had become supragingiva! and 43 (28 %) were located at the gingival crest. Altogether, 30 (].9 %) fillings remained subgingival but there was some evidence to suggest that resolution was incomplete and that further improvement might occur. The incidence of subgingival overhanging margins in the present study (prohing 100 %, radiographs 66 %) was higher than that found by other workers. Wright (1963) found that 57 % of the restorations in his patients had overhanging margins. Bjorn et al. (1969) found on radiographic examination that 31.9 % of premolar and 47.2 % of molar fillings had a subgingival excess of material. Gilmore & Sheiham (1971) reported that 23.9 % of all restored surfaces possessed overhangs. Leon (1976) examined 2,888 Class II amalgam restorations. Of these, 1,458 were below the gingival margin and 342 (23.52 %) had ledges or deficiencies. The higher incidence of amalgam with overhangs reported in the present study may be due to the use of a modified Cross ealculus probe to detect such defects, instead of the radiographic or other methods favored by most workers. Probing with this probe was preferred since a preliminary comparison showed it to be superior to radiographs as a means of detecting overhangs. As regards the mechanism whereby subgingivaliy placed amalgam exacerbates gingivitis, a number of workers have concluded that the effect is due mainly to increased accumulation of plaque (Waerhaug 1955, 1956, I960, Zander 1957, Wright 1963, Trott & Sherkat 1964, Karlsen 1970, Renggli & Regolati 1972). It is known from several studies (Lovdal et al. 1961, Lightner et al. 1971, Suomi et al. 1971, Axelsson & Lindhe 1974) that effective plaque control

103

can prevent gingivitis. The present study has shown that elimination of overhangs permits effective piaque control and the estabhshment of clinical gingival health. This is in agreement with the findings of Bjorn et al. (1969) and of Renggli & Regoiati (1972) who concluded from their epidemiological studies that overhangs enhanced plaque accumulation and the development of gingivitis. Similarly, Valderhaug & Birkeland (1976) and Valderhaug & Hel0e (1977) found more plaque accumulation and gingival inflammation, and deeper pockets in relation to subgingivally than to supragingivally placed crown margins. While surface properties and the position of the filling margin may enhance piaque accumulation and gingivitis, this study has shown that removal of overhangs coupled with subsequent effective oral hygiene is conducive to clinical gingival health.

Conclusions

1. Approximately only two-thirds of overhangs are detectable radiographically. Therefore clinical probing is important for the diagnosis as well as for evaluation of the removal of overhangs. 2. Plaque is more abundant and gingival inflammation more severe in relation to surfaces containing such defective fillings. 3. The removal of overhangs, in conjunction with scaling and oral hygiene instruction, results generally in subgingival restoration margins becoming supragingival after 2 months. This indicates that one should be prepared to wait at least 2 months in such instances before deciding whether surgery is necessary to correct this relationship. 4. Chemical properties of (silver) amalgam are unlikely to be significant, since improvement, indistinguishable after 8 weeks from that on the control side, was

GORZO, NEWMAN AND STRAHAN

104

produced by simple contouring of the defective restoration, scaling and oral hygiene being comparable on both sides. Zusammenfassung

Amalgamfiillungen, Plaqueentfernung und parodontale Gesundheit Bei 13 Patienten wurden 156 approximale, in den Seitenzahngehieten subgingival gelegene Fullungen ausgewablt um das AnsammeJn von Plaque, die Entziindung des Zahnfleischrandes, die Taschentiefen und gingivale Rezessionen zu studieren. Die oben genantiten Parameter wurden direkt vor der Entfernung des Zahnsteins, der Entfernung der uberhange und der Instruktion in oraler Hygie;ne, sowie 2, 4 und 8 Wochen danach registriert. Die Zahnflachen mit vorhandenen Uberbangen wurden mit Kontrollfiachen verglichen, die entweder voll intakt waren oder nur mit supragingivaien Amalgamfiillungen versorgt worden waren. Eingangs wurde gefunden, dass die Entzundung des Zahnfleisches und die Taschentiefen bei subgingivalen Amalgamfiillungen deutlicher bzw. tiefer waren als bei intakten oder mit supragingivaien Amalgamfullungen versorgten Zahnen. Dies schien mit der erhohten Tendenz zur Ansammlung von Plaque bei subgingivalen tJberhangen zusammetizuhangen. Bei alien hier verglichenen Parametem verschwanden jedoeh die beim Beginn des Versuches offenbaren Unterschiede am Ende der 8 wochentlichen Untersuchungsperiode. Wiederherstellung defekter Kontur bei subgingivalen Fullungen, gefolgt von effektiver Entfernung weicher und harter Belage und der Instruktion in oraler Hygiene resultierten in gingivaler Retraktion von etwa einem Millimeter und das reichte in den meisten Fallen aus, kiinisch gesunde gingivale Verhaltnisse zu schaffen. Von 156 subgingivalen Fuilungen befanden sich nach der 8-w6chigen Versuchsperiode 83 (53 %) supragingival und 43 (28 %) iti Hohe des Zahnfleischsaumes.

Resume

Obturations d'amalgame, elimitiation de ia plaque et sante du parodonte Chez 13 patients, 156 rebords sous-gingivatix en surplomb d'obturations d'amalgame piacees dans les segments posterieurs ant fait l'objet d'une evaluation eoncernant i'accumtilation de

Ia plaque microbienne, l'inflammation gingivale, la profondeur des culs-de-sac et la retraction gingivale. Les enregistements ont ete faits immediatement avant detartrage, elimination des surplombs et instruction d'hygiene bucco-dentaire, ainsi que 2, 4 et 8 semaine apres. Les surfaces avec surplomb ont ete comparees avec des surfaces temoins, qui etaient soit intactes soit obturees avec des amalgames sus-gingivaux. Au debut, I'inflammation gingivale et la profondeur des culs-de-sac trouvees etaient plus etendues au niveau des surplombs sous-gingivaux d'amalgame qu'au niveau des dents saines et des dents ayant des amalgames places au-dessus du rebord gingivai, Ce fait se revela etre dti a ce que les surpiombs sous-gingivaux constituaient un lieu de predilection pour l'accumulation de la plaque. Pour tous les parametres analyses, les differences constatees a I'examen initial avaient disparu a la fin des 8 semaines de I'etnde. La rectification des obturations sous-gingivales defectueuses, suivie d'un detartrage et d'une instruction d'hygiene bncco-dentaire efficaces produisaient nne retraction gingivale d'environ 1 mm et suffisaient dans la plupart des cas k ohtenir une gencive cliniquement saine. Sur les 156 obturations sous-gingivales, 83 (53 %) etaient devenues sns-gingivales et 43 (28 %) atteignaient la Crete gingivale a la fin des 8 semaines de cette etude.

References

Armitage, P, (1971) Statistical Methods in Medical Research. Oxford: Blackweli Scientific. Armitage, G. C, Svanberg, G. K. & Loe, H. (1977) Microscopic evaluation of clinicai measurements of connective tissue attachment levels. Journal of Clinical Periodontology 4, 173-190. Axelsson, P. & Lindhe, J. (1974) The effect of a preventive programme on dental plaque, gingivitis and caries in schoolchildren. Results after 1 and 2 years. Journal of Clinical Periodontology 1, 126-138. Bjorn, A, L., Bjorn, H. & Grkovic, B. (1969) Marginal fit of restorations and its relation to periodontal bone level, Odontologisk Revy 20, 311-321. Giimore, N. & Sheiham, A. (1971) Overhanging dental restorations and periodontal disease. Journal of Periodontology 42, 8-12. Hazen, S. P. & Osborne, J. W. (1967) Relationship of operative dentistry to periodontai

AMALGAM FILLINGS AND PERIODONTAL HEALTH health. Dental Clinics of North America , 245-254. Kaqueler, J. C. & Weiss, M. B. (1970) Plaque accumulation on dental restorative materials. Acta Odontologica Scandinavica 28, 895-904. Karlsen, K. (1970) Gingival reactions to dental restorations. Acta Odontologica Scandinavica 28, 895-904. Leon, A. R. (1976) Amalgam restorations and periodontal disease. British Dental Journai 140, 377-382. Lightner, L. M., O'Leary, T. & Drake, R. (1971) Preventive periodontic treatment procedures: Results over 46 months. Journal of Periodontoiogy 42, 555-561. Lovdal, A., Arno, A., Schei, O. & Waerhaug, J. (1961) Combined effect of subgingival scaling and controlled oral hygiene on the incidence of gingivitis. Acta Odontologica Scandinavica

19, 537—555.

Mitchell, D. (1959) The irritational qualities of dental materials. Journal of the American Dentat Association 59, 954-966. Mormann, W., Regolati, B. &. Renggli, H. H. (1974) Gingival reaction to well-fitted subgingival proximai gold inlays. Journal of Clinical Periodontology 1, 120-125. Muhlemann, H. & Son, S. (1971) Gingiva! sulcus bleeding - a leading symptom in initial gingivitis. Helvetica Odontologica Acta IS, 107-113. Renggli, H. & Regolati, B. (1972) Gingival inflammation and plaque accumulation by well-adapted subgingival and supragingival proximal restorations. Helvetica Odontologica Acta 15, 99-101. Silness, J. (1970) Periodontal condition in patients treated with dental bridges. III. The relationship between the location of the crown margin and the periodontal condition. Journal of Periodontal Research 5, 225-229. Silness, J. & Loe, H. (1964) Periodontal disease in pregnancy. 11. Correlation between oral hygiene and periodontal condition. Acta Odontologica Scandinavica 22, 121-135. Suomi, ]., Greene, J. & Vermillion, J. (1971) The effect of controlled oral hygiene proce-

105

dures on the progression of periodontal disease in adults: Results after third and final year. Journal of Periodontology 42, 152-160. Trott, J. & Sherkat, A. (1964) Effect of Class II amalgam restorations on health of the gingiva: A clinical survey. Journal of the Canadian Dental Association 30, 766-770. Valderhaug, J. & Birkeland, J. M. (1976) Periodontal conditions in patients 5 years following insertion of fixed prostheses. Journal of Oral Rehabilitation 3, 237-243. Valderhaug, J. & Hel0e, L. A. (1977) Oral hygiene in a group of supervised patients with fixed prostheses. Journal of Periodontology 48, 221-224. Waerhaug, J. (1955) Microscopic demonstration of tissue reaction incident to removal of subgingival calculus. Journal of Periodontology 26, 26-29. Waerhaag, J. (1956) Effect of rough surfaces upon gingiva! tissues. Journal of Dental Research 35, 323-325. Waerhaug, I. (1960) Histologic considerations which govern where the margin of restorations should be located in relation to the gingiva. Dental Clinics of North America , 167-176. Wright, W. (1963) Local factors in periodontal disease. Periodontics 1, 163. Abstract of research reports. Zander, H. (1957) Effect of silicate cement and amalgam on the gingiva. Journal of the American Dental Association 55, 11-15. Zeines, U. (1971) The effect of restorative materials on the periodontal tissue. A review of the literature. New York Journal of Dentistry 41, 101-105. Address: H. N. Newtnan Department of Periodontology Institute of Dental Surgeiy Eastman Dental Hospital Gray's Inn Road London WCl England

Amalgam restorations, plaque removal and periodontal health.

Journal of Clinical Periodontology: 1979: 6: 98-105 Key words: Amalgam restorations - ptaque control - Periodonia! health. Accepted for publication: M...
3MB Sizes 0 Downloads 0 Views