Retrograde root filling carefully enucleated from the exposed periodontal ligament space. Soft tissue around the root end may: a) make hemostasis more difficult; b) cause secretion of moisture to the peripheral part of the root end; c) react toxically to chemicals used on the root end; and d) entrap small strands of soft tissue between filling and root end, causing gaps. A hemostatic sponge (Spongostan, Ferrosan), moistened with maximum four drops of 1 % adrenaline, was placed foi" 3 min in the periapical area. The sponge was covered with gauze to keep the soft tissue away from the adrenaline so as to minimize resorption. (It was considered contraindicated to use adrenaline in case of heart disease, untreated hypertension, thyrotoxicosis, and during medication with tricyclic antidepressives or MAO-inhibitors). Residual hemorrhage was controlled with a needle suction (Fig. 2). Persistent bleeding sites were sometimes controlled by electric cauterization. Application of EDTA and Gluma - When hemostasis was established, the area was cleaned with saline and dried with compressed air. A foam sponge, with a diameter of approximately 1.5 mm, was soaked in 0.5 M EDTA, pH 7.4 (Gluma Cleanser) and rubbed on the resected surface for 20 s. After rinsing with a copious flow of saline and drying with air, Gluma
Eig. 1. Surplus of Retroplast. If apex is resected to level of bone cavity, it may be difficult to prevent filling material from spreading and covering periodontal ligament. It can be difficult to determine how much should be removed (A). If part of root can be preserved above cavity level, it is easier to fill slightly concave apex without surplus (B).
(Gluma Primer) was applied with a small sponge to the resected surface for 20 s and thoroughly dried. Hemostasis and absence of moisture were maintained during and after appHcation of Gluma. If the Gluma-saturated sponge was stained red during application (indicating bleeding), the bond between composite and dentin was considered compromised, and the entire filling procedure had to be repeated, including removal with a bur of the already treated dentin (1). Application of composite ~ Gare was taken not to exceed the working time of the chemically curing composite, Retroplast, during application (1). The entire resected root surface was covered with a thin layer of Retroplast by using a small excavator. If more than one root had to be treated, each root
Eig. 2. Needle-suction used to keep operative field dry when applying Retroplast fillings. Interchangeable needle is mounted on shortened suction tip (Loco), so that length and angulation correspond to "normal" suction tip in Coupland handle (HuFriedy).
127
Rud et ai. was treated independently. Three min. after curing, the composite surface was washed with 96% ethanol in order to remove the unpolymerized surface layer. The entire surgical area was then rinsed with saline. The treatment with alcohol and saline was repeated. If present, surplus of root filling material was removed with a bur after 10 min. Composite dust from the finishing procedure was removed with a copious flow of saline. Fig. 3 demonstrates a typical example of a tooth postoperatively and after 1 year in function. Patient material - The patients who were included in the study presented apical conditions, which allowed amalgam or composite to be used. It was ensured that the number of front teeth, premolars and molars were identical in the amalgam and composite filling groups. Excluded were palatal roots of molars, third molars or cases reoperated after initial placement of retrograde restorations. If two roots were treated, each root was evaluated separately. Composite - The surgical technique using composite was as described above. All operations were performed by one of the authors (JR or VR). 28 cases out of 428 consecutive Gluma-retained composite were excluded from the study for reasons considered not to be related to the method. The reasons for exclusion were: vertical root fracture, gingival retraction to the apex, lateral perforation during insertion of a post, total marginal periodontitis, radiographic overlapping of operated roots and/or radiographs of too inferior quality. The 400 cases which fulfilled the criteria were operated in a period from 1984 to 1988. 388 of the operations (97%) were followed-up afterwards. The 10 patients with the remaining fillings could not be traced or did not want to show up for control. Patients treated with composite were recalled 6 months after treatment, and usually also after 1 year. In cases where the 6-month recall showed either complete healing or failure, a 1-year control was not always per-
Fig. 3. Radicular cyst mesial to root of mandibular first premolar (A). Most of root preserved. Retroplast applied in thin layer, covering 2 root canals. Osseous healing after 1 year (B).
128
12
NO CONTROL
ONE YEAR ONLY
HALF AND ONE YEAR
HALF A YEAR ONLY
126 0
20
40
60
80 100 120 140 160 180
NUMBER OF PATIENTS
Fig. 4. Time at which the radiographic control was performed on patients supplied with Retroplast fillings. Total number with control was 388 cases.
formed. The distribution of the material according to length of observation is shown in Fig. 4. The age ranged from 15 to 93 years, with an average of 47 years. 4 1 % were men and 59% women. Amalgam - After apicoectomy, a slightly undercut cavity was prepared with a miniature contraangle handpiece following the direction of the root canal to a depth of approximately 2 mm. After hemostasis with a gauze pack, the cavity was filled with zincfree amalgam. The amalgam was properly condensed, burnished, and all surplus of material removed. 388 cases with retrograde amalgam fillings were selected randomly among patients previously treated by one of the authors (JR) and all controlled 1 year after the operation. The age distribution ranged from 19 to 83 years, with an average of 45 years. 33% were men and 67% women. Radiographic evaluation - Criteria used in the radiographic analysis, based on a combined histological and radiographic analysis of surgically treated endodontic cases, have been described previously (3). Classification into four categories was used: 1. Complete healing- A total bone regeneration with or without reformation of the periodontal ligament space and lamina dura. A slight increase in the width of the periodontal hgament space was accepted (up to twice normal width). A slight decrease in the radiopacity of the periapical space was accepted. 2. Incomplete healing (scar tissue) - The postoperative bony defect had decreased, but became stationary. The radiolucency was usually irregularly shaped and asymmetrically oriented in relation to the root, with an angular extension from the periodontal ligament space. Finally, the bone surrounding the radiolucency often had a lamellated appearance.
Retrograde root filling 3. Uncertain or developing healing - If cases did not Table 1. Classification of healing of cases with retrograde composite fillings according to types. 262 of the cases were observed after 1 year and 126 fulfil one of the three other healing categories, they after 6 months. were grouped as uncertain healing. 4. Non-healing (failures) - At a later control, the Healing type postoperative radiolucency had the same size, or Tooth type 1 3 2 4 had increased in size. Number scar complete uncertain failure In this study, failures were also cases where a maxilla Incisors and canines 43 11 5 4 loose composite filling could be seen. 63 68% 18% 8% 6% The healing evaluation was first made indepenPremolars 45 5 7 7 dently by three of the authors (JR, VR, JA). A 64 70% 11% 8% 11% consensus was then made on all cases where diverMolars 70 0 16 3 gent opinions existed. In this grouping of the ma89 79% 0 18% 3% terial, clinical information was included. Thus, if mandible Incisors and canines the case showed clinical sign of infection it was 20 0 9 7 36 56% 0 25% 19% considered a failure, irrespective of the radiographic appearance. Premolars 18 0 3 1 22 82% 0 14% 5% Statistical analysis - A statistical analysis of the results from healing scores of the groups representMolars 91 0 16 7 114 80% 0 14% 6% ing fillings with composite or with amalgam was made by using a two-sided Fisher's exact test at a Total 286 57 16 29 5% level of significance. Furthermore, the confi388 74% 4% 15% 7% dence intervals for therapeutic gain was determined for differences in healing between the two groups Postoperative condition - Postoperatively, 296 pa-
tients from the composite group and 330 from the amalgam group were seen by the authors (JR or VR). The rest of the patients, living out of town, were attended to by their local dentist. If the condition required treatment, the case was registered as postoperative complication. Results Frequency of healing of restorations with composite - At
the "last control" of the 388 cases, 262 cases were seen I year after treatment, and 126 after six
months. 74% of the cases showed complete healing (Fig. 5), 4% scar tissue, 15% uncertain healing, and 7% were failures. The relation between tooth types and healing is shown in Table 1. It can be seen that apart from the group mandibular incisors and canines, the proportions between healing categories were almost identical for all tooth groups. There was a significantly lower complete healing frequency (p = 0.02) among the mandibular incisors and canines treated compared to other teeth. Incomplete healing (scar tissue) was found only in the maxillary anterior and premolar regions. Frequency of healing of restorations with amalgam
-
Fig. 5. Retroplast fillings in lower first molar roots. Postoperative (A). Complete healings after 1 year (B).
129
Rud et al. Table 2. Classification of healing of cases with retrograde amalgam fillings according to types. A total of 388 cases were observed after one year.
RETROGRADE FILLING, AMALGAM/COMPOSITE AMALGAM
Healing type Tooth type Number maxilla
Incisors and canines
63 Premolars
64 Molars
89 mandible
Incisors and canines
36 Premolars
22 Molars
114 Total
388
1
2
complete
scar
3
COMPOSITE
4
uncertain failure
35 55%
7 11%
16 25%
5 8%
38 59%
3 5%
19 30%
4 6%
55 62%
1 1%
29 33%
4 4%
18 50%
2 6%
13 36%
3 8%
14 63%
0 0
4 18%
4 18%
69 61%
0 0
35 31%
10 9%
229 59%
13 3%
116 30%
30 8%
I
II
III
IV
TYPE OF HEALING Fig. 6. Frequency of healing for retrograde amalgam fillings after 1 year and for Retroplast fillings up to 1 year postoperatively. Types of healing are: I: complete healing. II: healing with scar tissue. I l l : uncertain or developing healing. IV: failures.
after operation, of the 388 composite cases 262 cases were seen after 1 year, 126 cases were seen only after 6 months. If all composite cases had been The results from the group of patients supplied with controlled 1 year after operation, more cases with amalgam fillings in various types of teeth, and obcomplete healing might have been found. With observed 1 year after operation, are shown in Table 2. servation periods of more than I year the frequency It appeared that there was no significant difference of completely healed cases might increase. Thus, between healing pattern and tooth type. However, in a previous study (5) with retrograde amalgam a tendency towards poorer healing was again found fillings, a healing rate of 57% found after 1 year, among mandibular incisors and canines. Scar tissue increased to 72% after 2 to 15 years, i.e. a net was found mainly in the maxillary anterior and gain in the healing rate of approximately 25%. The premolar regions. Comparison between frequencies of healing of restorations healing rate might be further increased by improvements of the surgical technique. In an analysis of with composite and with amalgam - A comparison was failures (1), it was seen that half of the cases were made between the two retrograde teechniques (Fig. caused by loose retrograde composite fillings. This 6). In this analysis, healing was grouped as either could have several causes. First, the time available complete healing or not complete i.e. Croup 1 vs Croups 2, 3, and 4 (Table 1, 2). In this analysis, composites showed significantly better healing than Table 3. Postoperative complications after use of retrograde amalgam and did amalgam (p< 0.00005). The therapeutic gain Retroplast. was 14.7% using composite (95% confidence interval was between 8.1% and 21.3%). Retroplast Amalgam Postoperative complications - By comparing the num-
ber of postoperative complications after 296 retrograde composite fillings and after 330 amalgam fillings, no significant differences were found. (Table 3). Discussion 74% of apical retrograde fillings with bonded composite showed complete healing. This figure might be increased: the cases registered as "scar tissue healing" (4%) could be considered a clinically acceptable form of healing, as it has been shown that scar tissue will eventually be replaced by bone (5); All 388 cases with amalgam were controlled 1 year 130
Cases observed postoperatively Cases with postoperative complications Types of postoperative complications Soreness, swelling Denuded bone Abcess Ostitis Sinuitis Treatment of postoperative complications Drainage Excocleation Eugenol dressing Antibiotics Extraction
296
330
24 (8%)
17 (5%)
17 (6%)
13 (4%)
2 4 2 1
12 (4%)
1 5 12(4%)
1
— 3 — 1
16 (5%)
— — 8(2%)
—
Retrograde root filling for handling the composite (in the beginning not more than 30-40 s) might have been exceeded. This technical problem has recendy been solved with a new composition of the retrograde filling material. Loosened composite could also be a result of contamination of the dentin surface or the Gluma-bonded layer with saliva or blood. This problem can be reduced with better hemostasis and moisture control. Such procedures have been described in this article. In general, patients with amalgam fillings showed 14% less complete heahng compared to patients with composite fillings. This conceivably may be explained by the ability of a composite to cover the entire resected surface, including lateral canals and infected dentinal tubules, exhibiting a gap-free interface between the filhng and dentin. In contrast to this, amalgam, at least initially, will demonstrate gaps between the filling and the canal walls and is not bonded to the dentin. Using scanning electron microscopy, Stabholz et al. (6) always found gaps between the amalgam and the dentin wall of the retrograde amalgam fillings. The width was around 30 |im. In a similar study, Moodnik et al. (7) found gaps ranging from 6 to 150 |^m. The reason why healing of retrograde amalgam fillings can occur at all might be the development of corrosion products filling out the gaps and the bacteriostatic effect of the metal ions. If the root canal has a post, a galvanic reaction may arise between the post and the amalgam. This may, however, result in development of excess corrosion products which can lead to periapical inflammation. In a study of 733 orthograde root fillings with gutta-percha made in connection with periapical surgery and 229 retrofillings using amalgam, Rud et al. (5) found 69% and 57%, respectively, with complete healing. This difference in healing was significant (p< 0.00005).
The figures for complete healing using amalgam were almost identical for the previous (5) and the present series (Table 2) (57% and 59%, respectively) . Comparing the rates for complete healing using retrofilhngs with dentin-bonded composite (74%, Table 1) with those for orthograde fillings with gutta-percha (69%), the difference was not significant (p = 0.15). The results in this study showed that bonded composite fillings possibly may improve the success rate of retrograde filhngs if long-term studies confirm these short-term results. Acknowledgement - This investigation was supported in part by the research foundation of the Danish Dental Association.
References 1.
RUD J , MUNKSGAARD EC, ANDREASEN JO, RUD V. Retrograde root filling with composite and a dentin-bonding agent. 1. Endod Dent Traumatol 1991; 7: 126-133.
2. RUD J, MUNKSGAARD EC, ANDREASEN JO, RUD V, ASMUSSEN
3. 4. 5.
6. 7.
E. Retrograde root filling with composite and a dentinbonding agent. I-VI. Danish Dental Journal 1989; 93: 157-60 195-7, 223-9, 267-73, 343-50. RUD J, ANDREASEN JO, JENSEN JEM. Radiographic criteria for the assessment of healing after endodontic surgery. Int J Oral Surg 1972; /.• 195-214. WuLFF HR, ScHLicHTiNG P. Medstut. Kebenhavn: Astra 1987. RUD J, ANDREASEN JO, JENSEN JEM. A follow-up study of 1,000 cases treated by endodontic surgery. Int J Oral Sure 1972; /.• 215-28. STABHOLZ A, SHANI J, FRIEDMAN S, ABED J. Marginal adaptation of retrograde fillings and its correlation with sealability. J Endod 1985; //.• 218-23. MOODNIK RM, LEVEY M H , BESEN MA, BORDEN B C . Retrograde amalgam filling: a scanning electron microscopic study. J Endod 1975; 1: 28-31.
131
Eig. 1. Surplus of Retroplast. If apex is resected to level of bone cavity, it may be difficult to prevent filling material from spreading and covering periodontal ligament. It can be difficult to determine how much should be removed (A). If part of root can be preserved above cavity level, it is easier to fill slightly concave apex without surplus (B).
(Gluma Primer) was applied with a small sponge to the resected surface for 20 s and thoroughly dried. Hemostasis and absence of moisture were maintained during and after appHcation of Gluma. If the Gluma-saturated sponge was stained red during application (indicating bleeding), the bond between composite and dentin was considered compromised, and the entire filling procedure had to be repeated, including removal with a bur of the already treated dentin (1). Application of composite ~ Gare was taken not to exceed the working time of the chemically curing composite, Retroplast, during application (1). The entire resected root surface was covered with a thin layer of Retroplast by using a small excavator. If more than one root had to be treated, each root
Eig. 2. Needle-suction used to keep operative field dry when applying Retroplast fillings. Interchangeable needle is mounted on shortened suction tip (Loco), so that length and angulation correspond to "normal" suction tip in Coupland handle (HuFriedy).
127
Rud et ai. was treated independently. Three min. after curing, the composite surface was washed with 96% ethanol in order to remove the unpolymerized surface layer. The entire surgical area was then rinsed with saline. The treatment with alcohol and saline was repeated. If present, surplus of root filling material was removed with a bur after 10 min. Composite dust from the finishing procedure was removed with a copious flow of saline. Fig. 3 demonstrates a typical example of a tooth postoperatively and after 1 year in function. Patient material - The patients who were included in the study presented apical conditions, which allowed amalgam or composite to be used. It was ensured that the number of front teeth, premolars and molars were identical in the amalgam and composite filling groups. Excluded were palatal roots of molars, third molars or cases reoperated after initial placement of retrograde restorations. If two roots were treated, each root was evaluated separately. Composite - The surgical technique using composite was as described above. All operations were performed by one of the authors (JR or VR). 28 cases out of 428 consecutive Gluma-retained composite were excluded from the study for reasons considered not to be related to the method. The reasons for exclusion were: vertical root fracture, gingival retraction to the apex, lateral perforation during insertion of a post, total marginal periodontitis, radiographic overlapping of operated roots and/or radiographs of too inferior quality. The 400 cases which fulfilled the criteria were operated in a period from 1984 to 1988. 388 of the operations (97%) were followed-up afterwards. The 10 patients with the remaining fillings could not be traced or did not want to show up for control. Patients treated with composite were recalled 6 months after treatment, and usually also after 1 year. In cases where the 6-month recall showed either complete healing or failure, a 1-year control was not always per-
Fig. 3. Radicular cyst mesial to root of mandibular first premolar (A). Most of root preserved. Retroplast applied in thin layer, covering 2 root canals. Osseous healing after 1 year (B).
128
12
NO CONTROL
ONE YEAR ONLY
HALF AND ONE YEAR
HALF A YEAR ONLY
126 0
20
40
60
80 100 120 140 160 180
NUMBER OF PATIENTS
Fig. 4. Time at which the radiographic control was performed on patients supplied with Retroplast fillings. Total number with control was 388 cases.
formed. The distribution of the material according to length of observation is shown in Fig. 4. The age ranged from 15 to 93 years, with an average of 47 years. 4 1 % were men and 59% women. Amalgam - After apicoectomy, a slightly undercut cavity was prepared with a miniature contraangle handpiece following the direction of the root canal to a depth of approximately 2 mm. After hemostasis with a gauze pack, the cavity was filled with zincfree amalgam. The amalgam was properly condensed, burnished, and all surplus of material removed. 388 cases with retrograde amalgam fillings were selected randomly among patients previously treated by one of the authors (JR) and all controlled 1 year after the operation. The age distribution ranged from 19 to 83 years, with an average of 45 years. 33% were men and 67% women. Radiographic evaluation - Criteria used in the radiographic analysis, based on a combined histological and radiographic analysis of surgically treated endodontic cases, have been described previously (3). Classification into four categories was used: 1. Complete healing- A total bone regeneration with or without reformation of the periodontal ligament space and lamina dura. A slight increase in the width of the periodontal hgament space was accepted (up to twice normal width). A slight decrease in the radiopacity of the periapical space was accepted. 2. Incomplete healing (scar tissue) - The postoperative bony defect had decreased, but became stationary. The radiolucency was usually irregularly shaped and asymmetrically oriented in relation to the root, with an angular extension from the periodontal ligament space. Finally, the bone surrounding the radiolucency often had a lamellated appearance.
Retrograde root filling 3. Uncertain or developing healing - If cases did not Table 1. Classification of healing of cases with retrograde composite fillings according to types. 262 of the cases were observed after 1 year and 126 fulfil one of the three other healing categories, they after 6 months. were grouped as uncertain healing. 4. Non-healing (failures) - At a later control, the Healing type postoperative radiolucency had the same size, or Tooth type 1 3 2 4 had increased in size. Number scar complete uncertain failure In this study, failures were also cases where a maxilla Incisors and canines 43 11 5 4 loose composite filling could be seen. 63 68% 18% 8% 6% The healing evaluation was first made indepenPremolars 45 5 7 7 dently by three of the authors (JR, VR, JA). A 64 70% 11% 8% 11% consensus was then made on all cases where diverMolars 70 0 16 3 gent opinions existed. In this grouping of the ma89 79% 0 18% 3% terial, clinical information was included. Thus, if mandible Incisors and canines the case showed clinical sign of infection it was 20 0 9 7 36 56% 0 25% 19% considered a failure, irrespective of the radiographic appearance. Premolars 18 0 3 1 22 82% 0 14% 5% Statistical analysis - A statistical analysis of the results from healing scores of the groups representMolars 91 0 16 7 114 80% 0 14% 6% ing fillings with composite or with amalgam was made by using a two-sided Fisher's exact test at a Total 286 57 16 29 5% level of significance. Furthermore, the confi388 74% 4% 15% 7% dence intervals for therapeutic gain was determined for differences in healing between the two groups Postoperative condition - Postoperatively, 296 pa-
tients from the composite group and 330 from the amalgam group were seen by the authors (JR or VR). The rest of the patients, living out of town, were attended to by their local dentist. If the condition required treatment, the case was registered as postoperative complication. Results Frequency of healing of restorations with composite - At
the "last control" of the 388 cases, 262 cases were seen I year after treatment, and 126 after six
months. 74% of the cases showed complete healing (Fig. 5), 4% scar tissue, 15% uncertain healing, and 7% were failures. The relation between tooth types and healing is shown in Table 1. It can be seen that apart from the group mandibular incisors and canines, the proportions between healing categories were almost identical for all tooth groups. There was a significantly lower complete healing frequency (p = 0.02) among the mandibular incisors and canines treated compared to other teeth. Incomplete healing (scar tissue) was found only in the maxillary anterior and premolar regions. Frequency of healing of restorations with amalgam
-
Fig. 5. Retroplast fillings in lower first molar roots. Postoperative (A). Complete healings after 1 year (B).
129
Rud et al. Table 2. Classification of healing of cases with retrograde amalgam fillings according to types. A total of 388 cases were observed after one year.
RETROGRADE FILLING, AMALGAM/COMPOSITE AMALGAM
Healing type Tooth type Number maxilla
Incisors and canines
63 Premolars
64 Molars
89 mandible
Incisors and canines
36 Premolars
22 Molars
114 Total
388
1
2
complete
scar
3
COMPOSITE
4
uncertain failure
35 55%
7 11%
16 25%
5 8%
38 59%
3 5%
19 30%
4 6%
55 62%
1 1%
29 33%
4 4%
18 50%
2 6%
13 36%
3 8%
14 63%
0 0
4 18%
4 18%
69 61%
0 0
35 31%
10 9%
229 59%
13 3%
116 30%
30 8%
I
II
III
IV
TYPE OF HEALING Fig. 6. Frequency of healing for retrograde amalgam fillings after 1 year and for Retroplast fillings up to 1 year postoperatively. Types of healing are: I: complete healing. II: healing with scar tissue. I l l : uncertain or developing healing. IV: failures.
after operation, of the 388 composite cases 262 cases were seen after 1 year, 126 cases were seen only after 6 months. If all composite cases had been The results from the group of patients supplied with controlled 1 year after operation, more cases with amalgam fillings in various types of teeth, and obcomplete healing might have been found. With observed 1 year after operation, are shown in Table 2. servation periods of more than I year the frequency It appeared that there was no significant difference of completely healed cases might increase. Thus, between healing pattern and tooth type. However, in a previous study (5) with retrograde amalgam a tendency towards poorer healing was again found fillings, a healing rate of 57% found after 1 year, among mandibular incisors and canines. Scar tissue increased to 72% after 2 to 15 years, i.e. a net was found mainly in the maxillary anterior and gain in the healing rate of approximately 25%. The premolar regions. Comparison between frequencies of healing of restorations healing rate might be further increased by improvements of the surgical technique. In an analysis of with composite and with amalgam - A comparison was failures (1), it was seen that half of the cases were made between the two retrograde teechniques (Fig. caused by loose retrograde composite fillings. This 6). In this analysis, healing was grouped as either could have several causes. First, the time available complete healing or not complete i.e. Croup 1 vs Croups 2, 3, and 4 (Table 1, 2). In this analysis, composites showed significantly better healing than Table 3. Postoperative complications after use of retrograde amalgam and did amalgam (p< 0.00005). The therapeutic gain Retroplast. was 14.7% using composite (95% confidence interval was between 8.1% and 21.3%). Retroplast Amalgam Postoperative complications - By comparing the num-
ber of postoperative complications after 296 retrograde composite fillings and after 330 amalgam fillings, no significant differences were found. (Table 3). Discussion 74% of apical retrograde fillings with bonded composite showed complete healing. This figure might be increased: the cases registered as "scar tissue healing" (4%) could be considered a clinically acceptable form of healing, as it has been shown that scar tissue will eventually be replaced by bone (5); All 388 cases with amalgam were controlled 1 year 130
Cases observed postoperatively Cases with postoperative complications Types of postoperative complications Soreness, swelling Denuded bone Abcess Ostitis Sinuitis Treatment of postoperative complications Drainage Excocleation Eugenol dressing Antibiotics Extraction
296
330
24 (8%)
17 (5%)
17 (6%)
13 (4%)
2 4 2 1
12 (4%)
1 5 12(4%)
1
— 3 — 1
16 (5%)
— — 8(2%)
—
Retrograde root filling for handling the composite (in the beginning not more than 30-40 s) might have been exceeded. This technical problem has recendy been solved with a new composition of the retrograde filling material. Loosened composite could also be a result of contamination of the dentin surface or the Gluma-bonded layer with saliva or blood. This problem can be reduced with better hemostasis and moisture control. Such procedures have been described in this article. In general, patients with amalgam fillings showed 14% less complete heahng compared to patients with composite fillings. This conceivably may be explained by the ability of a composite to cover the entire resected surface, including lateral canals and infected dentinal tubules, exhibiting a gap-free interface between the filhng and dentin. In contrast to this, amalgam, at least initially, will demonstrate gaps between the filling and the canal walls and is not bonded to the dentin. Using scanning electron microscopy, Stabholz et al. (6) always found gaps between the amalgam and the dentin wall of the retrograde amalgam fillings. The width was around 30 |im. In a similar study, Moodnik et al. (7) found gaps ranging from 6 to 150 |^m. The reason why healing of retrograde amalgam fillings can occur at all might be the development of corrosion products filling out the gaps and the bacteriostatic effect of the metal ions. If the root canal has a post, a galvanic reaction may arise between the post and the amalgam. This may, however, result in development of excess corrosion products which can lead to periapical inflammation. In a study of 733 orthograde root fillings with gutta-percha made in connection with periapical surgery and 229 retrofillings using amalgam, Rud et al. (5) found 69% and 57%, respectively, with complete healing. This difference in healing was significant (p< 0.00005).
The figures for complete healing using amalgam were almost identical for the previous (5) and the present series (Table 2) (57% and 59%, respectively) . Comparing the rates for complete healing using retrofilhngs with dentin-bonded composite (74%, Table 1) with those for orthograde fillings with gutta-percha (69%), the difference was not significant (p = 0.15). The results in this study showed that bonded composite fillings possibly may improve the success rate of retrograde filhngs if long-term studies confirm these short-term results. Acknowledgement - This investigation was supported in part by the research foundation of the Danish Dental Association.
References 1.
RUD J , MUNKSGAARD EC, ANDREASEN JO, RUD V. Retrograde root filling with composite and a dentin-bonding agent. 1. Endod Dent Traumatol 1991; 7: 126-133.
2. RUD J, MUNKSGAARD EC, ANDREASEN JO, RUD V, ASMUSSEN
3. 4. 5.
6. 7.
E. Retrograde root filling with composite and a dentinbonding agent. I-VI. Danish Dental Journal 1989; 93: 157-60 195-7, 223-9, 267-73, 343-50. RUD J, ANDREASEN JO, JENSEN JEM. Radiographic criteria for the assessment of healing after endodontic surgery. Int J Oral Surg 1972; /.• 195-214. WuLFF HR, ScHLicHTiNG P. Medstut. Kebenhavn: Astra 1987. RUD J, ANDREASEN JO, JENSEN JEM. A follow-up study of 1,000 cases treated by endodontic surgery. Int J Oral Sure 1972; /.• 215-28. STABHOLZ A, SHANI J, FRIEDMAN S, ABED J. Marginal adaptation of retrograde fillings and its correlation with sealability. J Endod 1985; //.• 218-23. MOODNIK RM, LEVEY M H , BESEN MA, BORDEN B C . Retrograde amalgam filling: a scanning electron microscopic study. J Endod 1975; 1: 28-31.
131
