Periapical Status of Non–root-filled Teeth with Resin Composite,Amalgam, or Full Crown Restorations: A Cross-sectional Study of a Swedish Adult Population

Introduction

Experimental studies show that dental pulp cells respond unfavorably to contact with resin composite restorative material. Hypothetically, in a random population, the frequency of apical periodontitis should be higher for teeth restored with resin composite than with amalgam. Therefore, the aim was to compare the periapical status of non–root-filled teeth restored with resin composite, amalgam, or laboratory-fabricated crowns in an adult Swedish population.

Methods

The subjects comprised 440 individuals from a randomly selected sample of 1,000 adult residents of a Swedish county. The type, material, and quality of the restorations were recorded for all non–root-filled teeth by clinical examination and intraoral clinical photographs. Periapical status was evaluated on panoramic radiographs. The association between periapical status and type, material, and quality of the restorations was analyzed using the chi-square test and logistic regression analysis.

Results

There was no significant difference in the frequency of apical periodontitis (AP) between teeth restored with resin composite or amalgam (1.3% and 1.1%, respectively). The frequency of AP for teeth restored with laboratory-fabricated crowns was significantly higher (6.3%). Regression analysis showed no association between AP and resin composite restorations but a significant association with laboratory-fabricated crowns.

Conclusions

The results indicate that the risk of damage to the pulp-dentin complex from exposure to resin composite material and dentin bonding agents shown in experimental studies is not reflected in the clinical setting. However, in the study sample, AP was diagnosed in a significantly higher proportion of teeth restored with laboratory-fabricated crowns.     

Effect of composite resin restorations in monkey teeth with experimentally induced pulpitis

abstract – The short- and long-term pulpal reactions to composite resin restorations using defferent cavity lining materials have been assessed in monkey teeth with experimentally indeced pulpitis. The inflammation was induced by fillion cavities with soft human carious dentin and amalgam for 1 week. Healing of the inflammation and formation of reparative dentin was generally found independent of the lining materials used. The long-term response to caviities restored with carious dentin and amalgam was also healing of the primarily induced pulpal inflammation in most instances.     

Pulp response in primary teeth with deep residual caries treated with silver fluoride and glass ionomer cement ('atraumatic' technique)

A bstract — Histological assessment of the dental pulps of 55 carious primary teeth was carried out 3 to 56 months after treatment by the 'atraumatic' technique involving application of 40 per cent silver fluoride to residual caries followed by restoration with glass ionomer cement. Fifty of the 55 teeth examined showed a favourable pulpal response, including presence of abundant reparative dentine and a wide odontoblast layer. Histological comparisons were made between these teeth and others not treated with silver fluoride but restored with glass ionomer cement, amalgam or zinc oxide and eugenol.
Possible mechanisms of the action of silver fluoride in arresting residual caries are discussed. The question of whether or not treatment of carious dentine with silver fluoride represents a biologically acceptable clinical procedure cannot be answered on the basis of pulpal histology alone. The very high concentration of fluoride in commercial preparations of silver fluoride raises several questions concerning its clinical safety.     

Effect of cobalt-60 radiation on the pulp of restored teeth.

The effect of cobalt-60 teletherapy on the pulps of restored teeth of monkeys was studied. Gold crowns and amalgam and composite resin restorations were placed in 28 teeth of two Macaca speciosa monkeys. One monkey then received cobalt-60 radiation to both maxillary and mandibular teeth and bones, with a total dose of 7,600 rads. Decalcified semiserial paraffin sections, 7 mum thick, of the teeth and supporting tissues were prepared and stained with hematoxylin and eosin. Microscopically, there was no discernible difference between the irradiated and the non-irradiated pulps.     

Pulpal responses to amalgam restorations in cavities with and without smear layer removal

A conventional low copper amalgam was placed in cavities with and without smear layer removal and the amalgam restorations were covered with a resin overlay. The restored teeth were retrieved at 2, 28 and 56 days postoperatively in order to test for leakage and then pulpal reactions. More inflammation was seen in the teeth from which the smear layer had been removed. Abscesses were present in 6 teeth at 28 days but only one was associated with demonstrable bacteria. This study does not support smear layer removal before insertion of low copper amalgam restorations.     

Dentinal fluid movement associated with loading of restorations

Post-operative biting sensitivity is a significant clinical problem after placement of posterior resin composites and may be due to dentinal fluid movement. The occlusal surfaces of extracted teeth were filled with amalgam (control) or various posterior resin composites, and the movement of the dentinal fluid induced by the loading of the restorations was studied. In addition, the firing of pulpal nerves induced by the loading of class 5 resin composite restorations in canine teeth of dogs was also investigated. When the entire cavity was etched with an acid gel and then filled with resin composite, dentinal fluid movement in response to loading was significantly (p less than 0.01) greater than in the amalgam-filled or unoperated controls. The dog canine tooth filled with resin composite showed firing of pulpal nerves when loaded. These results suggest that the movement of dentinal fluid induced by masticatory pressure on resin composite restorations may elicit biting sensitivity.     

Amalgam phase down: baseline data preceding implementation in Nigeria

Objective: The Minimata Convention on mercury includes amalgam phase-down and eventual phase-out from dentistry. To aid its subsequent evaluation it is important to have baseline data of amalgam use in a locality prior to implementing a phase-down. Methodology: Records of patients spanning 5 years from January 2011 to January 2016 were analysed to determine and the compare frequency of amalgam usage with other dental materials for carious teeth restorations in a Nigerian university teaching hospital. Classes of cavities restored and cadres of operators who employed the different materials were included. Institutional ethics committee approval was obtained prior to commencing the study. Results: 2,058 patients’ records were retrieved, 59% females and 41% males. Their ages ranged 19–80 years, mean 33.5 ± 12.7 years, young adults 20–39 years old were the majority (62.9%). Filling materials included 57.5% amalgam, 17.6% glass ionomer cement (GIC) and 24.9% resin composite. Class I restorations constituted 70.5% of amalgam restorations, while Class II restorations made up 29.4% and Class V restorations accounted for 0.1%. Undergraduate dental students placed most of the amalgam restorations (60.5%), and 78.9% of all their restorations were amalgam. Less experienced dentists used all materials equally; the more experienced dentists placed more composite resin and GIC (43.3%). Conclusion: Amalgam fillings constituted nearly 60% of the restorations of carious teeth. Training of dental students in placement of non-mercury alternatives to amalgam and Minimum Intervention Dentistry needs to be emphasized in dental schools. Phase-down of amalgam should be intensified in Nigeria with the ultimate aim of a phase-out in line with the Minamata Convention.Key words: Amalgam, phase-down, Nigeria, dental caries     

Outcomes of dental procedures performed on children under general anesthesia

The purpose of this study was to evaluate the integrity and longevity of restorative and pulpal procedures performed on primary teeth under general anesthesia (GA). Fifty-four children, who received comprehensive dental treatment under general anesthesia between 1993 and 1995, were included. The postoperative examination period ranged from 6 to 27 months. Children were examined and the quality of the restorations were recorded and evaluated. Behavior problems and inability to cooperate were the main reasons for treatment under GA. Results showed that restoration of posterior teeth with stainless steel crowns (SSC) were more successful (95.5%) when compared to amalgam or composite restorations (50%). In the anterior teeth, strip crowns had a success rate similar to that of Class III, IV and V composite resin materials. Pulpotomies showed an extremely high rate of success (97.1%), while sealants were retained 68.3% of the time. In conclusion, SSC are more likely to be successful and last longer than multisurface amalgam or composite restorations in children treated under general anesthesia. Definitive treatment is more likely to ensure a more positive outcome for children treated under general anesthesia due to less frequent complications from failed restorations or pulpal procedures.     

Survey on the teaching and use in dental schools of resin-based materials for restoring posterior teeth

A survey was conducted of 100 dental schools worldwide to investigate the current teaching of posterior resin composite restorations. A 20 multi-part question questionnaire was emailed to the selected schools. Schools were selected by ability to understand and respond in English. The questionnaire consisted of four open-ended questions and 16 closed questions on topics such as material selection for restoring posterior teeth, preclinical teaching of resin composite for posterior teeth, restoration size, contraindications, matrix placement methods, lining use, adhesive selection and finishing. Forty-six schools responded. The outcomes showed all schools included the teaching of resin composite for posterior restorations but varied. The majority of schools (63%) no longer taught amalgam as the preferred posterior restorative material. Half of the schools surveyed set numerical clinical requirements for restoration placement. Australian schools had no requirements whilst 92% of Asian schools did. There was a consensus that larger restorations were less suitable for resin composite. Selection of adhesives depended on region. Generally, the schools surveyed showed minor variations philosophically in teaching of the use and placement of resin composite restorations.     

Pulpal responses to amalgam restorations in cavities with and without smear layer removal

A conventional low copper amalgam was placed in cavities with and without smear layer removol and the amlagam restorations were covered with a resin overlay. The restored teeth were retrieved at 2, 28 and 56 days postoperatively in order to test for leakage and then pulpal reactions. More inflammation was seen in the teeth from which the smear layer had been removed. Abscesses were present in 6 teeth at 28 days but only one was associated with demonstrable bacteria. This study does not support smear layer removal before insertion of low copper amalgam restorations.     

Pulpal effects of electrosurgery involving based and unbased cervical amalgam restorations

The pulpal effects of electrosurgery involving unrestored enamel, cementum, calcium hydroxide-copal varnish-based restorations and unbased restorations were evaluated in extracted human teeth and posterior teeth of cynomolgus monkeys. Electrosurgery for all studies was performed with a fully rectified filtered unit under conditions of normal clinical usage. Studies in extracted human teeth measured the voltage potential generated between a reference probe in apical pulp tissue and an activated electrosurgery electrode placed on enamel, cementum, based restorations, and unbased restorations. Placement of a base reduced but did not prevent passage of electrosurgical current, and no measurable potential was associated with activated electrode contact on cementum or enamel. Studies in three cynomolgus monkeys included electrosurgery of based and unbased cervical silver amalgam restorations, electrosurgery of unrestored enamel, restored teeth not subjected to electrosurgery and teeth that were neither restored nor subjected to electrosurgery. Electrosurgery of restored teeth, regardless of the presence of a base, consistently resulted in pulpal damage characterized by an altered dentin matrix, necrosis adjacent to the cavity preparation, and a transition zone between necrotic and apparently vital pulp tissue. By 8 weeks following electrosurgery, the majority of specimens showed replacement of the odontoblastic layer and adjacent pulp tissue by dense connective tissue with areas of irregular calcification.     

Monkey pulpal response to composite resin restorations in cavities treated with various cleansing agents

Abstract— Pulpal response to composite resin restorations placed in experimentally prepared cavities treated with various cavity cleansing and etching agents were studied in monkey teeth. The use of etching agents and cleansers with a demineralizing potential enhanced the pulpal response to composite resin restorations. Bacterial proliferation on the cavity walls around the composite restorations may be one of several factors causing the harmful pulpal responses found. The protective effect of a calcium hydroxide-containing cavity lining material was confirmed.     

Endodontic complications after plastic restorations in general practice

AIM: To test the hypothesis that dentine and pulp protection by conditioning-and-sealing is no less effective than using a conventional calcium hydroxide lining. METHODOLOGY: A cohort of healthy adults requiring a new or replacement restoration in a posterior tooth was recruited in six general practices. All procedures received local Ethics Committee approval. Exclusion criteria included signs and symptoms of pulp necrosis or inflammation, and patients unable to commit to a long-term trial. Cavity preparations were randomized to receive a calcium hydroxide lining or conditioning-and-sealing with a smear-removing bonding system. Choice of bulk restorative material (composite resin or amalgam) was at the discretion of the dentist. The key outcome measure was evidence of pulpal breakdown identified at unscheduled (emergency) or scheduled recall examinations. Postoperative sensitivity was recorded on 100 mm VAS at 24 h, 4 days and 7 days. Pulp status was assessed at 6, 12, 24 and 36 month recall, and at any emergency recall appointment. The relationship between pre-treatment and treatment variables and pulp breakdown was assessed by logistic regression (P = 0.05). RESULTS: A total of 602 teeth were recruited, with comparable numbers of cavities lined (288, 47.8%) or conditioned and sealed (314, 52.2%). The majority (492, 81.7%) were replacement restorations, and amalgam was the most common bulk restorative material (377, 62.6%). A total of 390 (64.8%) restored teeth were reviewed at 6 months, 307 (51%) at 12 months, 363 (60.3%) at 24 months, and 279 (46.3%) at 36 months post-restoration. Sixteen cases of pulp breakdown were identified within 36 months of restoration placement, 11 presenting as emergencies and five detected at routine recall examination. Logistic regression showed that preoperative pain, cavity treatment by lining or conditioning-and-sealing and the use of rubber dam isolation had no association with pulp breakdown. Pulp breakdown was associated with deep or pulpally exposed cavities (P < 0.001, odds ratio 7.8) and with composite rather than amalgam restorations (P = 0.001, odds ratio 2.13). Re-coding to identify teeth with pulp exposures revealed that pulpal exposure was the key determinant of adverse pulp outcomes (P < 0.0001, odds ratio 28.4) and that composite resin restorations were again more likely to be associated with pulp breakdown than amalgam (P = 0.017, odds ratio 3.92). CONCLUSIONS: Considered within the context of routine primary dental care: Dentists can be confident that pulps will be equally well protected from post-restorative breakdown up to 36 months by calcium hydroxide lining and conditioning-and-sealing with adhesive resins. Residual dentine thickness appears to be a key determinant of pulp responses after restorative dental treatment. In deep and pulpally exposed cavities in posterior teeth, composites were associated with more pulpal breakdown than amalgams.     

Replica patterns on composite restorations performed in vitro with different acid-etch procedures and dentin adhesives

160 experimental Class V restorations using two chemically cured composite resins were inserted in extracted human teeth with conventional and modified acid-etch restorative procedures. The modifications included cavity treatment with non-composite resin, ethanol, or four different dentin adhesives. Following demineralization of the teeth the fillings were examined in the SEM concerning their replica patterns of the etched cavity walls. In vitro conditions favored resin penetration into pretreated enamel and dentin, but resulted in minor variations between different acid-etch procedures compared with those previously seen on resin restorations placed in vivo in teeth with vital pulps.     

Marginal microleakage of resin-retained bridges in association with existing resin composite and amalgam restorations

The aim of this study was to determine the microleakage associated with resin-retained bridge retainers cemented over amalgam and resin composite restorations. Cavities prepared on the labial surfaces of bovine incisors were restored with either amalgam or a posterior resin composite. Non-precious nickel-chromium alloy frameworks were then attached to the teeth by use of one of four cements: Conclude, ABC, Panavia Ex, and Superbond. The specimens were then stored for two weeks or six months, thermocycled, and tested for microleakage by use of a radioactive tracer and an autoradiographic technique. The results showed that more leakage was associated with the amalgam restorations than with the teeth filled with resin composite. Leakage scores increased with time with both the amalgam and composite restorations, except for the Panavia Ex and ABC materials, respectively.     

Marginal adaptation of amalgam and resin composite restorations in Class II conservative preparations.

OBJECTIVE: The purpose of this study was to compare and contrast the performance, in terms of marginal adaptation, of a non-gamma-2 amalgam alloy with a compact-filled light-cured composite in the restoration of Class II preparations of conservative design. METHOD AND MATERIALS: Fifty recently extracted teeth were selected for the study. The teeth were restored with either a non-gamma-2 amalgam alloy, Dispersalloy, or a compact-filled resin composite, Z100, using standard techniques. The marginal adaptation of the restorative materials to the proximal surface outline form of each preparation was assessed at magnification x30. RESULTS: Highly significant differences were demonstrated in the mean percentages of perfect margins in all 3 segments of the proximal boxes of the restorations with the resin composite performing significantly better than the amalgam. The percentages of marginal fissuring were significantly higher in the amalgam restorations, except at the cervical margin, where the incidence of fissuring was almost the same for the amalgam and resin composite restorations. The resin composite restorations had significantly fewer underfilled margins than the amalgam restorations. CONCLUSION: In the conservative Class II preparations, the amalgam restorations were of poor quality with respect to marginal adaptation, compared with the resin composite restorations. It is suggested that the use of amalgam as a control in a clinical evaluation of resin composite restorations in conservative preparations cannot be justified, because it is apparently not possible to compare restorations of equivalent initial quality.     

Effect of bonded restorations on the fracture resistance of root filled teeth

AIM: To evaluate the fracture resistance of root filled maxillary premolars restored with different techniques. METHODOLOGY: One hundred and twenty single-rooted maxillary premolar teeth were divided randomly into six groups of 20 teeth and subjected to the following procedures: group 1: intact teeth. Group 2: endodontic access cavities prepared. Group 3: MOD cavities were prepared, root canals were filled and no restoration was placed. Group 4: teeth were prepared as group 3 and restored conventionally with amalgam. Group 5: teeth were prepared as group 3 and restored with amalgam using a bonding material. Group 6: teeth were prepared as group 3 and restored with composite resin using the same bonding material. Teeth were embedded in acrylic resin and the loads for fracture strength were applied vertically with a constant speed of 1 mm min(-1). Data were evaluated statistically with anova and Tukey's tests. RESULTS: The mean force of fracture values were 1191.41, 599.86, 233.03, 494.72, 962.81 and 856.48 N for groups 1, 2, 3, 4, 5 and 6, respectively. The fracture resistance of group 5 was similar to group 1 (P > 0.05). The mean force at fracture of group 5 and group 6 was not significantly different. The fracture resistance of groups 5 and 6 was significantly higher than group 4 (P < 0.001). CONCLUSIONS: The group, restored with conventional amalgam, had the weakest resistance to fracture when compared with the bonded restorations. No statistically significant differences were found between the bonded amalgam and composite resin groups.     

Replica patterns on composite restorations performed in vitro with different acid-etch procedures and dentin adhesives

Abstract — 160 experimental Class V restorations using two chemically cured composite resins were inserted in extracted human teeth wjth conventional and modified acid-etch restorative procedures. The modifications included cavity treatment with non-composite resin, ethanol, or four different dentin adhesives. Following deemineralization of the teeth the fillings were examined in the SEM cuncerning their replica patterns 01 the etched cavity walls. In vitro conditions favored resin penetration into pretreated cnarnel and dentin; but resulted in minor variations between diltrerent acid-etch procedures compared with those previously seen on resin restorations plawd in viva in teeth with vital pulps.     

Fracture strength of amalgam crowns with repaired endodontic access

Endodontic therapy is accessed occlusally in posterior teeth, many of which have large, pre-existing amalgam restorations. These teeth are also commonly restored with an occlusal amalgam to repair the access opening. This study determined the fracture resistance of complex amalgam restorations that have repaired endodontic access compared with original, unrepaired, complex amalgams on endodontically-treated teeth. Two groups of 30 molars were used in the study. The first group was decoronated and received an endodontic access preparation. These teeth were restored using chamber retention and four TMS pins. The second group was decoronated and restored using pin retention. Later, they received an endodontic access through the restoration. The access was then repaired with amalgam. The samples were loaded in an Instron Universal Testing Machine until failure. The Group 1 samples failed at a mean force of 2297.5 N. The mean failure load for the samples in Group 2 was 1586.1 N. Student's t-test found this difference to be statistically significant. Endodontic access through an amalgam crown significantly compromises the fracture strength of the original restoration.     

Composite or amalgam? Not a black or white decision

Amalgam as a restorative material in dentistry is discussed because of believed toxic properties of the material, yet there is no scientific prove for the assumption. Adhesive restorations are a possible alternative for amalgam in restoring posterior teeth. For treatment of primary caries, the direct composite resin restoration has many advantages. When greater defects are to be restored, adhesive composite resin restorations become less favourable. At this moment no long term results are available for indirect adhesive techniques. For the time being it seems necessary to use composite resin as well as amalgam for the restoration of posterior teeth.