Ten-year longitudinal clinical evaluation of a visible light cured posterior composite resin

Using modified USPHS criteria, we evaluated annually for ten years 91 cases restored with visible light cured posterior composite resin LFP (Base resin: UDMA; filler: micro crushed type, alumino-silicate, barium glass and silica, 85 wt%, 74 vol%). The 91 cases restored with LFP decreased to 68 in ten years. Of the 23 cases that were lost, one resulted from a pulpal reaction immediately following restoration, four were extracted owing to periodontal disease or extrusion of third molars, two became abutments owing to loss of an adjacent tooth, eight had recurrent caries, and eight were lost owing to caries on a surface having no relationship to the composite resin restoration. Because we observed comparatively little wear, good marginal adaptability, and no discoloration, we concluded that the ten-year clinical success of LFP was on the whole very good, and that this resin has adequate clinical merit as a restorative material for posterior teeth when restricted to restorations covering comparatively small areas.     

Atraumatic restorative treatment and glass-ionomer sealants in a school oral health programme in Zimbabwe: evaluation after 1 year

An oral health care programme in secondary schools using the atraumatic restorative treatment (ART) technique for dental caries was started in 1993. Glass-ionomer was used as the restorative and sealant material. Sealants were placed using the "press finger' technique. Results after 1 year revealed a survival percentage for one-surface ART restorations of 93.4 whilst the complete and partial retention percentages for sealants were 60.3 and 13.4, respectively. No caries was observed in teeth restored using ART, and only 0.8% of surfaces diagnosed as having early enamel lesions at the start of the programme and sealed consequently had progressed into active dentinal lesions after 1 year. The sealant retention percentage and the survival percentage of ART restorations were influenced by an operator effect. The majority of restorations were carried out without administering local anaesthesia. The mean treatment time for one-surface ART restorations was 22.1 min (range per operator of 19.8-23.6 min), whilst the mean time for placing sealants was 9.4 min (range per operator of 8.2-10.8 min). Post-operative sensitivity was reported for 6% of the teeth restored. 95% of the students were satisfied with ART as a treatment modality. It is concluded that ART may in part be the answer to the unavailability of restorative care for many population groups globally.     

Comparative study of antifungal activity of sertaconazole, terbinafine, and bifonazole against clinical isolates of Candida spp., Cryptococcus neoformans and dermatophytes

The aim of this study was to investigate the visibility of secondary caries in the gingivobuccal and gingivolingual corners of teeth restored with amalgam restorations. Standard Class II cavities were created in 15 orthodontically extracted mandibular premolar teeth, and the teeth were randomly divided into five groups of three teeth each. In four of the groups, a 1.0- or 1.5-mm cavity was prepared in the gingivolingual or gingivobuccal corner of the restoration. No lesions were created in group 5, the control group. The teeth were restored with amalgam. The teeth were adapted in the actual tooth space of 15 volunteers with one mandibular premolar missing. Radiographs of each patient were taken with the bisecting-angle technique and the bite wing technique. The radiographs were sorted at random and given to 15 members of the professoriate who were often involved in detecting caries and to 17 members who were not normally involved in detecting caries. The bitewing technique was found to be more reliable than the bisecting-angle technique in detecting secondary caries in gingivobuccal approximal corners (P < .05). It was also found that, in group 1, the bisecting-angle technique was more reliable than the bitewing technique in detecting caries in gingivolingual corners (P < .05). No significant differences were found in the correct evaluation of radiographs between the faculty who were normally involved in the detection of caries and those who were not.     

Porcelain veneers for primary incisors: a case report

A 4-year-old boy with severely discolored primary maxillary incisors was treated with bonded porcelain veneer restorations. Two years previously, the child had been treated with topical application of sodium fluoride-silver nitrate solution to arrest dental caries associated with a nursing bottle habit. With minimal chair time, the incisors were restored with laboratory-processed porcelain veneer restorations that were bonded with resin cement. This is perhaps the only report to date of the use of porcelain veneer restorations for primary anterior teeth.     

Artificial caries formation around fluoride-releasing restorations in roots

Secondary caries is one of the most important factors leading to replacement of dental restorations. This investigation assessed the capacity of fluoride-releasing restorative materials to resist caries in vitro when used in roots. Class 5 cavities were prepared in the buccal and lingual surfaces of 30 extracted premolars. The six materials used were: glass-ionomer cement (Fuji), glass-ionomer cement with silver particles added (Ketac-silver), fluoride-containing composite resin (Tetric), composite resin (Silux plus), fluoride-containing amalgam (Fluor-Alloy) and high-copper amalgam (Dispersalloy). After 5 weeks in an acid gel for caries-like lesion formation, the teeth were sectioned longitudinally and examined with polarized light. The results showed that repair with glass-ionomer materials of a carious lesion may be of great importance in the prevention of secondary caries around the restorations in roots.     

Caries diagnosis with dye-staining at amalgam restoration margins

PURPOSE: To determine the strength of agreement between detection of caries at the margin of amalgam restorations with a caries detector dye, and detection of caries histologically utilizing light/polarizing light microscopy. MATERIALS AND METHODS: 17 permanent molars with intact amalgam restorations, determined to be caries-free by visual inspection and explorer probing, cleansed with an air/water/abrasive slurry system, and with evidence of amalgam enamel marginal staining from application of a 1% solution of sulforhodamine B caries detector dye were utilized. Longitudinal, undecalcified sections, 80-100 micrometers thick, were prepared including stained and unstained regions of the amalgam/enamel margin of each tooth, providing 34 margins for study. The sections were examined in the light/polarizing light microscope for evidence of marginal caries. The Kappa Index was calculated to determine the strength of agreement between the caries dye method and the light/polarizing light microscopic method of caries diagnosis. RESULTS: Microscopically, caries was detected in 14 of 34 margins (41%). Agreement for presence of caries was 5 of 34, and for absence of caries 8 of 34 (total agreement 38%). 12 of 17 dye-stained margins were microscopically caries-free, and 9 of 17 unstained margins had caries microscopically. Kappa Index for these findings was 0.23, indicating poor strength of agreement.     

Insulin effects on ouabain binding in A6 renal cells

OBJECTIVES: This study sought to identify risk markers associated with the provision of new restorations in children and to investigate whether the carious status of a tooth surface is associated with the restorative decisions of dentists. METHODS: A total of 911 schoolchildren in grades one, two, and three were randomly selected from the island of Montreal, Quebec, Canada. Dental examinations were carried out in 1990, 1991, and 1992. Tooth surfaces of first permanent molars were classified as sound, noncavitated, and cavitated. The carious status of a tooth was matched with restorative decisions reported to the insurance board. RESULTS: The presence of a carious cavity was a strong risk marker for placement of new restorations (odds rations > or = 4.11). After one year, less than 2 percent of sound tooth surfaces of first permanent molars were restored and about 21 percent of noncavitated tooth surfaces were restored. When new class I restorations placed in maxillary first permanent molars within 3-6 months after the baseline examination were evaluated, we found that between 73 percent and 86 percent of these new restorations were placed in sound or noncavitated tooth surfaces. A similar trend also was observed in mandibular first permanent molars. Poor agreement between epidemiologic diagnosis and restorative decisions was found. The restorative profile of dentists was a significant risk marker for placement of new restorations. CONCLUSION: The majority of new restorations in first permanent molars were placed in sound and noncavitated tooth surfaces because of the ubiquitous prevalence of these tooth surfaces and the validity problems of current caries diagnosis methods.     

The epidemiology of Neisseria gonorrhoeae isolates in Greenland 1979-1990: the emergence, spread and disappearance of non-PPNG strains carrying the conjugative 38.9 kb plasmid

The aim of this study was to compare the clinical performance of an amalgam, a glass polyalkenoate (ionomer) cerment material and a resin-based composite material used in small Class II cavities in permanent teeth. All restorations were inserted under rubber dam. They were examined yearly for 3 years. One clinician continued the study up to 5 years. The clinical examination focused on two criteria: clinically acceptable and failure. In addition, impressions were taken of the prepared cavities immediately before restoration and at each clinical examination using an elastomeric material. The study comprised 274 Class II restorations (88 amalgams, 95 cerments and 91 resin composites) placed in 142 adolescent patients. One hundred and sixty-seven restorations were in molar and 107 in premolar teeth. Patient dropout after 5 years resulted in the loss of 161 restorations, evenly distributed for restorative material and type of tooth involved. Four amalgam restorations, 22 glass ionomer cerment and nine resin composite restorations failed. The glass ionomer cerment and amalgam restorations failed primarily due to bulk fractures, while the resin composite restorations failed due to secondary caries and bulk fractures.     

The effect of a resin-modified glass ionomer restorative material on artificially demineralised dentine caries in vitro

OBJECTIVES: Recurrent caries is one of the most common reasons for the replacement of restorations. One method of reducing the frequency of this problem may be by using fluoride-releasing restorative materials. The aim of this in vitro study was to evaluate the progression of artificial lesions around resin-modified glass ionomer (Vitremer) restorations placed in root surfaces. Class V cavities were prepared on the mesial and distal surfaces of 28 human premolar teeth. Artificial carious wall lesions were created in all cavities. The root of each tooth was then hemisected through the middle of the two cavities, before being restored with either the glass ionomer or amalgam, while the opposing cavities on the same root portion were varnished as negative controls. Forty-eight specimens were pH-cycled in remineralising and demineralising solutions for 20 h and 4 h, respectively, each day for 4 weeks, whilst in a smaller control group of eight specimens, the demineralising solution was replaced with deionised water. Mineral changes in the carious lesions were evaluated using contact microradiography. RESULTS: Results showed that varying degrees of subsurface demineralisation and remineralisation were evident, with a laminated appearance in lesions adjacent to the glass ionomer. There was higher remineralisation in the glass ionomer-filled cavities compared with the amalgam-filled cavities. In the water-cycled group, glass ionomer showed an increase in mineral content (p < 0.05), while no changes were observed in the amalgam-filled cavities. CONCLUSIONS: This model has shown that glass ionomer has a greater potential than amalgam for remineralisation of artificially created wall lesions within an acidic environment.     

Clinical evaluation of sodium fluoride chewable tablets in dental caries

Chewable tablets containing low dosage fluoride content were prepared using two varieties of celluloses and their in vitro parameters were evaluated. An eighteen month clinical trial revealed that both these formulations were effective in controlling the caries. However, ethyl cellulose is proved to be superior to methylcellulose as a controlled release matrix material in controlling caries. Thus this study recommends ethylcellulose matrix tablets containing low fluoride content is an efficacious and cost effective drug device in controlling dental caries.     

Replacements of restorations in the primary and young permanent dentition

The present study focused on the type of restorative material used and the reasons for replacements of restorations in the primary and the young permanent dentition. All patients with restorations and who were 8 and 19 years of age in 1995 and were regularly treated at 11 Public Dental Health clinics in J?nk?ping County, Sweden, participated in the study. Data were extracted from the records for all types of restorations in canines and molars for the preceeding of 5 years for the 8-year-olds (i.e. from 3 to 8 years of age; n = 546) and for approximal restorations in premolars and molars for the preceeding 13 years for the 19-year-olds (i.e. from 6 to 19 years of age; n = 606). In all, 6012 restorations were evaluated. The two most common restorative materials used in the primary dentition were compomer and glass ionomer cement and in the young permanent dentition composite and amalgam. In the primary dentition, 29% of the restorations had been replaced and 4% of the teeth with restorations had been extracted. Thus, 33% of the restorations in the primary dentition failed. The corresponding figure for the young permanent dentition was 13%. The most common reason for replacements in the permanent dentition was secondary caries. That restorations often fail because of caries and that the development of secondary caries is not prevented by replacement of an old restoration indicate that more attention should be paid to preventive dental care for patients with restorations in the primary as well as in the young permanent dentition.     

Amalgam alternatives--micro-leakage evaluation of clinical procedures. Part I: direct composite/composite inlay/ceramic inlay

This study investigated the degree of dye penetration with three different types of tooth-coloured restorations. Twenty-four intact extracted molars were collected. The teeth were immediately stored in water at room temperature. Class II cavity preparations were prepared and restored with three different types of tooth-coloured restorations: A, composite resin in the incremental technique; B, composite inlay technique; and C, ceramic inlay. Specimens were subjected to 700 cycles of thermal stress. They were than immersed in 2% basic fuchsin dye. The teeth were sectioned in three planes before being ranked as to the amount of dye penetration. The highest score obtained on three plano-parallel sections was adopted as the representative value. The three groups were compared using the Kruskal Wallis non-parametric test. Dye penetration was significantly lower at the enamel margins when using the composite inlay system and the incremental technique compared to the ceramic inlay technique. The restorations placed using the composite inlay technique showed less dye penetration than the incremental technique at the dentine margins (P < 0.017).     

New techniques for guiding catheter management during directional coronary atherectomy

In an uncontrolled retrospective recall study of 57 patients treated with conical crown retained dentures, 60 restorations (37 in the maxillae and 23 in the mandible jaw) with a mean wearing time of 30.1 months (range 4 to 76) were evaluated. Of the 248 abutments, eight (3.2%) had been lost. Clinically healthy mucosa was seen in 35 jaws. The marginal fit of the copings was judged to be good. No caries or new restorations were observed in 44 patients. Thirteen patients had 19 surfaces with new restorations and 20 surfaces with caries lesions. Of these 39 surfaces, 38 were located subgingivally.     

Tunnel restorations. A 3 1/2-year follow up study of Class I and II tunnel restorations in permanent and primary teeth

During 1988-89, 224 patients with approximal caries in the premolar/molar regions were provided with 318 tunnel restorations. In case of perforation of the enamel in the enamel/dentin border, (23%), complete Class II-tunnel restorations with glass ionomer cement and composite resin were made. In case of "intact" enamel, (77%), partial Class I-tunnel restorations were made. The restorations were controlled at annual routine recalls and the success rate after 3 1/2 years was 74% for permanent teeth, and 10% for primary teeth. Restorations in permanent teeth, made during the second year of the study were successful in 82%, as compared with 62% for restorations made during the first year, indicating a learning effect. Failures in the permanent dentition were due to marginal ridge fracture (35%), cavitation in the approximal enamel (31%), and recurrent caries (38%). Failures in primary teeth were predominantly due to marginal ridge fractures (84%). A comparison with the longevity of conventional Class II restorations is made and the possible advantages of the present method are presented.     

Luting composite thickness of two ceramic inlay systems

The objective of this study was to evaluate the effects of glass-ceramic inserts on reducing the marginal gaps caused by polymerization shrinkage in composite restorations. A light microscope was used to measure the largest gap at margins around restorations made in glass cylinders and tooth cavities with and without adhesion promoters. Where the cylinder was not silanated, the average gap was less in samples containing an insert than in those without. Two preparations were made in the dentin of 20 human molars. In each molar one cavity was restored with a dentin bonding agent and composite and the other with a dentin bonding agent and an insert seated in the composite. The average maximum gap width of restorations containing inserts was statistically less than for those with only composite (paired t-test, P<0.0001). When considering the volume of composite displaced by the insert, these results that the use of a glass-ceramic insert decreased the marginal gaps resulting form polymerization shrinkage.     

Effect of restored and unrestored non-carious cervical lesions on the fracture resistance of previously restored maxillary premolar teeth

OBJECTIVES: The effect of non-carious cervical lesions (NCCL) on tooth fracture resistance has not previously been investigated. The aims of this in vitro study were to examine the fracture resistance of a group of extracted maxillary premolar teeth with mesio-occlusal-distal (MOD) restorations of amalgam, and restored or unrestored simulated NCCL. METHOD: Forty sound maxillary, premolar teeth were divided at random into four groups, each of 10 teeth, which were fixed crown uppermost and long axis vertical in stainless steel moulds. Groups 1,2,3 and 4 were prepared with standardized parallel-sided MOD cavities, then restored with amalgam. Groups 1, 2 and 3 were further prepared with standardized NCCL. The NCCL in Group 1 were restored using a resin-modified polyalkenoate (glass-ionomer) cement, and the NCCL in Group 2 were restored with an adhesive composite resin system. The NCCL in Group 3 were left unrestored. The specimens were loaded compressively at 1 mm min-1 using a universal testing machine. RESULTS: Mean fracture loads (KN) of 1.08, 1.03, 0.98 and 1.14, respectively, were recorded for Groups 1, 2, 3 and 4. Two-way ANOVA and Scheffe's Multiple Range Test showed no statistically significant difference between the groups. CONCLUSIONS: It is concluded that the presence of a standardized NCCL in an extracted maxillary premolar tooth does not reduce the fracture resistance of the tooth when loaded compressively at 1 mm min-1. The restoration of NCCL with the materials tested did not result in an increase in the fracture resistance of the previously restored premolar teeth, when loaded compressively at 1 mm min-1.     

Microleakage of cervical restorations etched with a weak organic acid

This in-vitro study evaluated the microleakage of Class V restorations prepared using 10 per cent maleic acid and a composite resin. Thirty human premolar teeth were evenly distributed and randomly assigned to three groups. Conventional retentive preparations, etched with 10 per cent maleic acid for either 15, 30, or 60 seconds, were cut in the enamel on the facial surface of each tooth to a 1.5 mm depth (dentin). All teeth were restored with Z-100, a small particle composite resin. The teeth were then stored in deionized water for seven days, thermocycled, stained with methylene blue dye, invested, and sectioned vertically through the centre of the restoration. Leakage was established along each wall of the sectioned restoration. Analysis of variance (ANOVA) tests indicate that the restored teeth in Group 1 (15-second etch) had significantly greater microleakage (p < 0.05) on the enamel wall than the restored teeth in Group 2 (30-second etch) or Group 3 (60-second etch). In addition, Group 1 restorations had significantly greater overall microleakage (p < 0.05) than Group 2 or Group 3 restorations. Although the results were not statistically significant, it would appear that etching with 10 per cent maleic acid for 30 seconds could be clinically significant. Since a 30-second etch time was found to produce the least amount of microleakage (not statistically significant), it can be assumed that this etch time would also be optimal for etching enamel and dentin. Similarly, since Group 1 revealed the most overall microleakage, it can be assumed that a 15-second etch would be inadequate for etching enamel and dentin. Restorations in Groups 2 and 3 displayed statistically significant lower overall microleakage results.     

Dietary amino acids as new and novel agents to enhance allograft survival

Little is known about the long-term effects of fluoride-releasing materials on carious dentine in vivo. The aim was to investigate the 2-year influence of a resin-modified glass ionomer cement (RM-GIC) and amalgam on the bacteriological counts of carious dentine that remained under class I restorations. To enable a split-mouth design, 33 molar pairs in 33 patients (mean age 15.1 years, SD 1.4) were selected, based on clinically and radiographically diagnosed occlusal dentine caries. The enamel of the carious molars was removed, and the carious dentine was sampled under aseptic conditions just beneath the dentinoenamel junction. The molars were alternately restored with RM-GIC or amalgam without further removal of carious dentine. The samples were processed for microbiological determination of total viable counts (TVC), mutans streptococci (MS), and lactobacilli (LB). The molar pairs of 25 patients were reevaluated after 2 years using the same clinical techniques and were permanently restored after complete caries removal. Both materials showed a substantial decrease in numbers of TVC and LB of the carious dentine after the 2-year period. Compared to amalgam, the decrease in the numbers of LB was significantly more pronounced for RM-GIC. No microorganisms were detected in only 11 molars (6 RM-GIC and 5 amalgam) after the 2-year period. Based on this study, we suggest that complete removal of carious dentine is still the best conservative treatment, irrespective of the restorative material used.     

Prevalence and depth of artificial caries-like lesions adjacent to cavities prepared in roots and restored with a glass ionomer or a dentin-bonded composite material

One potential advantage of glass-ionomer materials for the treatment of root caries is their ability to release fluoride and so resist cariogenic attack. A commercially available composite material has also been reported to release fluoride which reduced caries lesions in the tooth tissue adjacent to it. The aim of this study was to assess the effectiveness of a conventional glass-ionomer restoration compared with a dentin-bonded, fluoride-releasing, composite restoration when exposed to a microbial artificial caries system. Artificial caries-like lesions produced in relation to the restorations were examined and classified either as outer (surface) lesions or as wall lesions. A split-unit experimental design allowed for within-tooth comparisons of the 2 experimental restorations at different sites on the root surface. These were either totally within the root surface or positioned at the amelo-cemental junction. Outer lesion depths were significantly (p < 0.001) shallower at all sites adjacent to the glass ionomer when compared with the composite restorations. Wall lesions were significantly (p < 0.01) more prevalent adjacent to the composite material. In addition, the cavity margin position significantly (p < 0.05) affected the incidence of wall lesions, particularly in the composite group. In conclusion, glass ionomer was successful in reducing the caries-like lesion production in the adjacent root surface. This resulted from improved marginal integrity and fluoride release from this material when compared with the composite bonding system used.     

Three-year clinical evaluation of the Clearfil Liner Bond system

Modern dental adhesive systems have improved the bond of restorative materials to mineralized tooth structures. The purpose of this study was to evaluate the clinical performance of composite restorations placed in abrasion and erosion lesions using the Clearfil Liner Bond dental adhesive system. Following ADA clinical guidelines for dentin and enamel adhesive materials, 62 facial class 5 smooth surface erosion or abrasion lesions with no undercuts and involving primarily root surfaces were restored in 25 adult male and female patients. The teeth were restored without preparations using Clearfil Liner Bond and Clearfil Photo Anterior composite resin. The clinical performance of the restorations was assessed by two examiners at baseline, 6 months, 1, 2, and 3 years using the following evaluative parameters: color match, marginal discoloration, and marginal integrity according to modified Ryge criteria; the presence or absence of recurrent decay; pre- and postoperative sensitivity; and restoration failure due to loss of retention or other causes. At the end of 3 years, four of the 55 restorations remaining in the study failed due to lack of retention (92.7% retention rate). The evaluations of the other clinical parameters demonstrated excellent performance by this system.