Microbiological and SEM assessment of atraumatic restorative treatment in adult dentition

OBJECTIVES

To investigate the practicability of atraumatic restorative treatment (ART) in adults in terms of marginal adaptation of restorations and microbiological changes in residual carious dentin.

MATERIALS AND METHODS

The occlusal dentin caries of 25 permanent molar teeth were removed with hand instruments. The total counts of bacteria (TCB) and the facultative anaerobic bacteria (FAB), mutans streptococci (MS), and Lactobacillus spp. (LB) counts in the affected dentin were evaluated quantitatively. The weights of the samples were measured with an electronic balance (Shimadzu, Type AX200, Japan). The cavities were restored with glass ionomer cement (Ketac^TM Molar Easymix, ESPE Dental AG, Seefeld, Germany). Twenty replicas of randomly selected ART restorations were prepared and marginal adaptation was evaluated by scanning electron microscopy (SEM). After 6 months, the same protocols were repeated. Data were analyzed with paired sample t-tests, Wilcoxon t-tests, Pearson and Spearman correlations, and chi-square tests (p<0.05).

RESULTS

In the sixth month, restoration loss and pulpitis were not observed. The mean weight of samples removed from the cavity floor was less than the baseline (0.014±0.009 and 0.023±0.013 g, respectively) (p<0.01), and the counts of total bacteria, FAB, MS, and LB significantly decreased compared to baseline (p<0.01). The frequency of marginal gaps was increased (p< 0.01).

CONCLUSIONS

ART showed that the counts of microorganisms decreased after 6 months although the marginal gap rates of restorations increased.

CLINICAL RELEVANCE

ART can be a reliable treatment approach in adults for 6 months due to the decrease in microorganism counts, although gaps exist.

Effect of Thermo-mechanical Load Cycling on Microleakage in Class II Ormocer Restorations

Objectives: The objective of this in vitro study was to evaluate the marginal sealing ability of an ormocer in comparison with a hybrid composite when using thermocycling and load cycling procedures together in the study design.

Methods: Modified proximal Class II cavities were prepared on the mesial and distal surfaces of twenty-two human premolars. Each tooth was restored with Admira and contralaterally with TPH Spectrum. Half of all of the teeth were subjected to thermo-mechanical load cycling. After dye penetration, longitudinal sections in mesio-distal direction were prepared and examined under a stereomicroscope. Data were analyzed with Mann Whitney U test.

Results: The results showed that the thermo-mechanical load cycling caused a statistically significant increase in gingival microleakage when compared with the non-thermocycled and nonloaded restorations for both the materials Admira (P=0.006) and TPH Spectrum (P=0.023).

Conclusions: Simultaneous load cycling and thermocycling are decisive factors in the in vitro assessment of gingival microleakage, which still remains to be a clinical problem even with the ormocer system Admira. (Eur J Dent 2009;3:200-206)

Influence of Different Restoration Techniques on Fracture Resistance of Root-filled Teeth: In Vitro Investigation

OBJECTIVE

The purpose of this study was to determine the fracture strength of endodontically treated mandibular premolar teeth restored with composites and different reinforcement techniques.

METHODS AND MATERIALS

Forty-eight freshly extracted human mandibular premolar teeth were randomly divided into four groups: group IN, group CR, group FRC, and group PRF. Group IN consisted of teeth with intact crowns and served as the control group. In the other three groups, endodontic treatment was performed and standard mesio-occluso-distal (MOD) cavities were prepared. Then cavities were restored with hybrid resin composite only, flowable composite and hybrid resin composite, and Ribbond, flowable composite and hybrid resin composite in groups CR, FRC and PRF, respectively. All of the teeth were subjected to fracture by means of a universal testing machine, and compressive force was applied with a modified stainless-steel ball at a crosshead speed at 0.5 mm/min.

RESULTS

The highest values were observed in group IN, while the lowest values were determined in group CR. There was not any statistically significant difference between group CR and group FCR ( p>0.05). When groups CR, FCR, and PRF were compared, group PRF showed significantly better fracture strength than did groups CR and FCR ( p<0.05). It was determined that there was not any significant difference between group IN and group PRF ( p>0.05).

CONCLUSIONS

Polyethylene ribbon fiber considerably increases the fracture strength of mandibular premolar teeth with MOD cavities restored with composite.

Microtensile bond strength to enamel affected by hypoplastic amelogenesis imperfecta

PURPOSE

This study compared the microtensile bond strengths (μTBS) of two different self-etching (SE) and etchand- rinse (ER) adhesive systems to enamel affected by hypoplastic amelogenesis imperfecta (HPAI) and analyzed the enamel etching patterns created by the two adhesive systems using scanning electron microscopy (SEM).

MATERIALS AND METHODS

Sixteen extracted HPAI-affected molars were used for the bond strength tests and 2 molars were examined under SEM for etching patterns. The control groups consisted of 12 healthy third molars for μTBS tests and two molars for SEM. Mesial and distal surfaces of the teeth were slightly ground flat. The adhesive systems and composite resin were applied to the flat enamel surfaces according to the manufacturers' instructions. The tooth slabs containing composite resin material on their mesial and distal surfaces were cut in the mesio-distal direction with a slow-speed diamond saw. The slabs were cut again to obtain square, 1-mm-thick sticks. Finally, each stick was divided into halves and placed in the μTBS tester. Bond strength tests were performed at a speed of 0.5 mm/min. Data were analyzed with two-way ANOVA and Tukey's tests.

RESULTS

There was no significant difference between the bond strength values of ER and SE adhesives (p > 0.05). However, significant differences were found between HPAI and control groups (p < 0.05). HPAI-affected enamel surfaces exhibited mild intra- and inter-prismatic enamel etching patterns after orthophosphoric acid application, while conditioning of HPAI-affected enamel with SE primer created a slightly rough and grooved surface.

CONCLUSION

SE and ER adhesive systems provide similar bond strengths to HPAI-affected enamel surfaces.

Combined periodontal and restorative approach to the treatment of gingival recessions with noncarious cervical lesions: a case treated with acellular dermal matrix allograft and compomer restorations

Treatment of gingival recessions has become one of the most challenging procedures in periodontal plastic surgery. Various surgical options with predictable outcomes are available, but in cases with cervical lesions or restorations, optimal functional and esthetic results may require the combination of periodontal and restorative procedures. In this case report, one patient treated with acellular dermal matrix allograft and a coronally positioned flap in combination with compomer cervical restorations is presented. Clinical parameters were recorded immediately prior to surgery and after 12 months. Postoperatively, significant root coverage, reductions in probing depths, and gains in clinical attachment were observed. The final clinical results, esthetics, color match, and tissue contours were acceptable to both the patient and clinicians.

Effect of Thermo-mechanical Load Cycling on Microleakage in Class II Ormocer Restorations

OBJECTIVES

The objective of this in vitro study was to evaluate the marginal sealing ability of an ormocer in comparison with a hybrid composite when using thermocycling and load cycling procedures together in the study design.

METHODS

Modified proximal Class II cavities were prepared on the mesial and distal surfaces of twenty-two human premolars. Each tooth was restored with Admira and contralaterally with TPH Spectrum. Half of all of the teeth were subjected to thermo-mechanical load cycling. After dye penetration, longitudinal sections in mesio-distal direction were prepared and examined under a stereomicroscope. Data were analyzed with Mann Whitney U test.

RESULTS

The results showed that the thermo-mechanical load cycling caused a statistically significant increase in gingival microleakage when compared with the non-thermocycled and non-loaded restorations for both the materials Admira (P=0.006) and TPH Spectrum (P=0.023).

CONCLUSIONS

Simultaneous load cycling and thermocycling are decisive factors in the in vitro assessment of gingival microleakage, which still remains to be a clinical problem even with the ormocer system Admira.

Two-year clinical evaluation of ormocer and nanofill composite with and without a flowable liner

PURPOSE

The aim of this clinical follow-up study was to determine the clinical performance of ormocer and a new nanofill composite material, lined or not lined with flowable composites, after 2 years.

MATERIALS AND METHODS

Occlusal restorations (n = 108) were placed in 54 patients with two symmetric restorations per patient. In one of the two restorations in each patient, cavities were first lined with the flowable composite material Admira Flow or Filtek Flow after applying the two-step total-etch one-bottle adhesive (Admira Bond) or single bond adhesive (Single Bond). Admira or Filtek Supreme was then applied. Restorations were examined using the USPHS modified Ryge criteria for retention, color matching, cavosurface marginal discoloration, anatomic form, marginal adaptation, surface texture, and secondary caries by two previously calibrated dentists. The overall performance of the restorations was evaluated by Wilcoxon signed ranks test. The chi-square test was used to determine differences in the performance of the restorations in which the flowable composite was applied first.

RESULTS

There was no secondary caries or postoperative sensitivity in any of the restorations at the 6-month, 1-year, and 2-year follow-up examinations. After 2 years, only one Admira restoration had failed; all other restorations were available for evaluation. There were no statistically significant differences among the materials regardless of the prior use of flowable material (p > 0.05). There was no statistically significant difference between the restorations with and without the prior application of flowable materials (p > 0.05).

CONCLUSION

The clinical performance of occlusal restorations using ormocer or nanofill composite did not benefit from the additional use of the flowable composite. Both of the restorative materials exhibited ideal clinical performance.

Effect of resin-based material combination on the compressive and the flexural strength

The mechanical properties, elasticity and compressive strength, of restorative materials play a crucial role during mastication for clinical performance of materials in particular stress bearing areas at posterior regions. This in vitro study was objected to evaluate the changes in the compressive and flexural strength of tooth-coloured resin-based dental restorations placed on flowable composites. Specimens in the control group were produced in cylindrical form for testing compressive strength and in quadrangular prism form for flexural strength test. Tetric Ceram, Charisma, Surefil, Admira and two compomers; Dyract AP and Compoglass F in test group specimens were fabricated by placing the control materials on different flowables. The material combinations were as follows: Tetric Ceram/Tetric Flow Charisma/Flowline, Surefil/Dyract Flow, Admira/Admira Flow, Dyract AP/Dyract Flow, Compoglass F/Compoglass Flow. Compressive strength values were measured at the Instron Testing Machine with a cross-head speed of 10 mm min(-1) while flexural strength were determined in three-point bending with a cross-head speed of 1 mm min(-1). One-way anova and Tukey's multiple comparison tests were performed for the statistical analysis. The flexural strength values of Tetric Ceram/Tetric Flow (135.9 +/- 3.2), Charisma/Flowline (120.4 +/- 5.6) and Compoglass F/Compoglass Flow (108.2 +/- 5.2) combinations were statistically greater than Tetric Ceram (110.8 +/- 10.5), Charisma (95.3 +/- 5.3) and Compoglass F (86.9 +/- 4.9). The results of the present study support the idea that the placement of flowable composite as a liner under the resin-based composite restoratives increase the flexural strength.

A comparative study of two fissure sealants: a 2-year clinical follow-up

The aim of the study was to compare the fluoride-containing fissure sealants (Helioseal F) with the conventional (Concise Light Cure White Sealant) fissure sealants in their retention and caries-prevention capabilities in young population. Sealant materials were applied by three dentists on 122 fissures of first and second molars in 59 adults, 18-20 years of age. One hundred and twenty-two non-carious and unsealed molar teeth were selected as controls. The teeth were assessed using the following criteria: 1 - fully retained (FR), 2 - partially lost (PL), 3 - totally lost (TL) and 4 - decayed (D). All teeth were clinically assessed at 3, 6, 12 and 24 months by two examiners who were blinded to the sealant materials. Data were statistically analysed with chi-square tests. After 3 months 72.1% of sealants were fully retained, at 24 months this had dropped to 46.7%. The partial loss of sealants was at 3 months (15.6%), 6 months (26.2%), 12 months (27.9%) and 24 months (27%). The total loss of Helioseal F (16.4, 19.7, 18, 23% at 3rd, 6th, 12th and 24th months, respectively) was more than the total loss of Concise Light Cure White Sealant (8.2, 9.8, 11.5, 18%, respectively); meaning that the retention rate of Helioseal F was lower than for Concise Light Cure White Sealant. No caries was detected at 3rd and 6th months in all sealant-treated teeth. The incidence of caries in Helioseal F treated teeth at 12 and 24 months was 11.5% and 0% in Concise Light Cure White Sealant treated teeth. The incidence of caries in all fissure-sealant-treated-teeth after 24 months was 5.7 and 25.4% in control group. The results underline that the application of fissure sealants to young people in this sample is an effective method for the prevention of fissure caries.

In vitro effect of cavity disinfectants on the bond strength of dentin bonding systems

OBJECTIVE

To evaluate the effect of two cavity disinfectants, a 2% chlorhexidine and a 1% benzalkonium chloride solution, on the shear and tensile bond strengths of dentin bonding systems to dentin.

METHOD AND MATERIALS

Superficial dentin was exposed from 84 freshly extracted human third molars. The teeth were randomly assigned to two main groups according to the bonding agent used, either One Step or Optibond Solo. Each dentin bonding system had six test groups (three for shear, three for tensile testing), and each test group had a control and two cavity disinfectant groups. In the control groups, dentin bonding systems were applied after etching the dentin, whereas in the cavity disinfectant groups, dentin was conditioned and treated for 20 seconds with the disinfectants before applying the dentin bonding systems. A hybrid resin composite then was applied to all treated samples. After storage in distilled water at 37 degrees C for 24 hours, shear and tensile tests were performed. Data were analyzed using Kruskall-Wallis and Mann-Whitney U tests.

RESULTS

The mean shear and tensile bond strengths of One Step and Optibond Solo were not significantly different from each other, and the cavity disinfectants also had no significant effects on shear and tensile bond strength values versus the controls.

CONCLUSION

The results indicate that the use of 2% chlorhexidine and 1% benzalkonium chloride solutions as cavity disinfectants after etching the dentin did not affect the shear and tensile bond strengths of One Step and Optibond Solo.

Dental caries and fluorosis in low- and high-fluoride areas in Turkey

OBJECTIVE

The aim of this study was to investigate the caries prevalence of children living in either low- or high-fluoride areas and to relate caries experience to the severity of dental fluorosis.

METHOD AND MATERIALS

A total of 278 12- to 14-year-old schoolchildren, 149 in a low-fluoride area (LFA) and 129 in a high-fluoride area (HFA), were included in the study. The naturally occurring fluoride concentrations in the drinking water were 0.30 to 0.40 ppm in the LFA, 1.42 to 1.54 ppm in the HFA1, and 1.55 to 1.66 ppm in the HFA2. Dental caries was recorded with the World Health Organization criteria, and dental fluorosis was measured using the Tooth Surface Index of Fluorosis.

RESULTS

The percentages of children who had an average TSIF > or = 1 were 0%, 29%, and 77% in the LFA, HFA1, and HFA2, respectively. The mean decayed, missing, and filled permanent teeth (DMFT) and decayed, missing, and filled permanent surfaces (DMFS) were 0.84 +/- 0.98 and 1.58 +/- 2.24 in LFA, 1.30 +/- 1.46 and 1.78 +/- 2.52 in HFA1, and 1.26 +/- 1.42 and 1.97 +/- 2.60 in HFA2, respectively. There was no significant difference in caries prevalence among children living in low- and high-fluoride areas when evaluated with an analysis of covariance model, including the frequency of toothbrushing. Toothbrushing frequency had a significant effect on the decayed teeth, decayed surfaces, DMFT, and DMFS. In high-fluoride areas, there was no relationship between caries prevalence and severity of fluorosis.

CONCLUSION

Increasing water fluoride levels were associated with higher prevalence and severity of dental fluorosis and had no influence on caries experience in children with poor oral hygiene.

Bond strength of a resin composite to a polyacid-modified resin composite under different conditions

OBJECTIVE

The aim of this in vitro study was to evaluate the tensile bond strength values between polyacid-modified resin composite ("compomer") and resin composite materials under different conditions.

METHOD AND MATERIALS

There were five experimental groups in the study. In group A, resin composite was placed directly on polyacid-modified resin composite surfaces. In group B, bonding agent was applied to polyacid-modified resin composite surfaces and then resin composite was placed on the compomer. In group C, compomer specimens were stored for 1 week and then resin composite was placed directly on these aged compomers. In group D, compomer specimens were again stored for 1 week, and then the bonding agent and resin composite were applied to the compomer surfaces. In group E, the surfaces of aged (1 week) compomers were roughened before the bonding agent was applied and the resin composite was placed on the prepared surfaces. A statistical analysis of the results was made with the Kruskal-Wallis test method.

RESULTS

The mean tensile strength values of the groups were as follows: group A = 12.84 MPa; group B = 15.03 MPa; group C = 10.60 MPa; group D = 11.56 MPa; group E = 24.87 MPa. There were statistically significant differences between groups E and A; groups E and C; groups E and D; and groups C and B.

CONCLUSION

Mechanical roughening of a polyacid-modified resin composite surface was found to be the most effective factor in increasing the tensile bond strength between an aged compomer and a resin composite.

Alstrom syndrome: a case report

Alstrom syndrome is a rare disorder characterized by early obesity, loss of central vision, diabetes mellitus, hearing loss and short stature. Previous studies, have reported no information regarding oral findings. This article describes oral findings in two cases of Alstrom syndrome. In both cases, gingivitis was present and also light yellow-brown discolored enamel bands were observed on the anterior teeth. This staining may have resulted from discoloration of the preexisting slight band-like enamel hypoplasia. The gingiva was examined histologically by light and transmission electron microscopy. Irregular thickness of the basal lamina and delamination of the myelin sheath were detected by transmission electron microscopy. There is no information about pathological odontogenesis in Alstrom syndrome in previous reports. Oral present findings may contribute further information about the clinical manifestations of Alstrom syndrome.

The relation between salivary IgA and caries in renal transplant patients

OBJECTIVE

The purpose of this study was to evaluate the effect of immunosuppressive drugs on the level of salivary immunoglobulin A (IgA) in patients who have received kidney transplants and the relation between the levels of salivary IgA and dental caries incidence.

STUDY DESIGN

Patients who had undergone renal transplantation (n = 28, aged 18-54) were divided into 3 groups according to postsurgical period (0-6 months [G(1)], 6-12 months [G(2)], and >12 months [G(3)]). A healthy control group (n = 10, aged 17-49) was also included in this study. Saliva samples were collected from all patients by the spitting method. After collection, the samples were frozen immediately at -40 degrees C until analysis by the single radial immunodiffusion method. All fissure caries were examined clinically, and proximal caries were examined clinically and radiographically; caries status was determined according to the decay surface index. The findings were evaluated statistically by means of correlation analysis, the Kolmogorov-Smirnov test, and the 1-way Kruskal Wallis analysis of variance method.

RESULTS

Salivary IgA levels of the patients who had undergone renal transplantation were found to be significantly lower than those of the control patients (G(1) = 6.76 mg/dL, G(2) = 6.80 mg/dL, G(3) = 7.84 mg/dL, and control group = 10.84 mg/dL, P <.001). However, the caries status of the patients who had undergone renal transplantation was not different from that of the control subjects for the first year after the transplant operation. The salivary IgA values of the 3 groups of patients who had undergone transplantation were not significantly different from each other. Thus, it was observed that a decrease in the level of salivary IgA does not result in an increase in caries incidence within 12 months after renal transplantation. The caries rate in the third group of patients who had undergone renal transplantation was found to be significantly different from those in the first and second groups.

CONCLUSION

Low salivary IgA levels caused by immunosuppression are not correlated or associated with higher levels of dental caries within the first 12 months after renal transplantation. However, the incidence of dental caries was higher for patients who had undergone renal transplantation than for control subjects 12 months after renal transplantation. Because of the diagnostic processes used, dental caries may not become evident until after 12 months.

Monitoring the caries risk of orthodontic patients

Several caries activity tests were used to investigate the caries risk of patients with fixed orthodontic appliances. Twenty young individuals, with a mean age of 11 years, participated in this study. Ten subjects were free of any orthodontic appliances and formed the control group. The other 10 individuals had been wearing fixed orthodontic appliances for at least 4 months. Stimulated saliva samples were obtained from all patients. Saliva samples were used to investigate the salivary flow rate, the salivary buffer capacity, and mutans streptococci and lactobacilli counts. The orthodontic patients exhibited a significant increase in salivary flow rate. Results of statistical analyses were nonsignificant in all other tests, suggesting that fixed orthodontic appliances are not the sole factor increasing the patient's caries risk during orthodontic treatment.

Investigation of the aetiopathogenesis of amelogenesis imperfecta through microscopic, submicroscopic and cytogenetic methods--a case report

A case of hypomineralized type of amelogenesis imperfecta has been evaluated by using microscopic, submicroscopic and cytogenetic techniques. It has been observed that some of the enamel contained hydroxyapatite crystals and showed normal mineralization, but some others consisted of transparent, crystal plates of octacalcium phosphate, revealing that these enamel prisms have hypomature characteristics. Extra chromosomes which belong to D-autosomes were found in the culture obtained from the peripheral blood of the patient, suggesting that the patient has 15% hyperdiploids. It is suggested that the structural disorders in some of the enamel prisms resulted from alterations in the environmental conditions related to chromosome anomalies.