Antibacterial Effect of Surface Pretreatment Techniques against Streptococcus Mutans.

OBJECTIVE: The aim of this study was to evaluate the antibacterial surface pretreatment methods against Streptococcus mutans within the infected dentin surface using a tooth cavity model. MATERIAL AND METHODS: Seventy-two cavities were prepared on caries-free third molars (n = 8). After sterilization, teeth were inoculated with S. mutans for 48 h. One cavity of each tooth was used to evaluate the infection. Following inoculation, infected cavity surfaces were treated either with (1) Er:YAG Laser (1W; 5x5s, Smart 2940D Plus, Deka Laser), (2) Ozone (80s; HealOzone, Kavo), (3) ErYAG-Ozone combination, (4) Er:YAG-Ozone-CHX combination, (5) Chlorhexidine (CHX), (6) Clearfil Protect Bond (PB), (7) potassium-titanyl-phosphate (KTP) Laser (1W; 60 s, SMARTLITE D, Deka Laser), (8) KTP-Ozone combination, and (9) KTP-Ozone-CHX. Standardized amounts of dentin chips were obtained from the cavity walls, and the number of bacteria recovered was counted. Kruskal-Wallis test was used for statistical analyzes. RESULTS: Both sole antibacterial materials, CHX or Protect Bond application, exhibited the most effective antibacterial activity with 125 and 156 CFU is an acronym of "colony forming unit" usullay mentioned by acronym. (CFU/ml), respectively, among the groups evaluated (P < 0.05). Er:YAG laser irradiation and its combinations with other antibacterial surface pretreatment applications also inhibited the bacterial growth with, respectively, 1444, 406, and 294 CFU/ml bacterial recovery being more efficient than KTP laser irradiation and ozone combinations. CONCLUSIONS: As an alternative device with photodynamic effects, Er:YAG and KTP laser irradiations and their further combinations during the cavity pretreatment procedure with chlorhexidine and ozone treatments exerted antibacterial effect against S. mutans, whereas chlorhexidine and antibacterial dentin bonding application solely have the highest antibacterial effects.

The effect of calcium phosphate-containing desensitizing agent on the microtensile bond strength of multimode adhesive agent.

OBJECTIVE: The aim of this study was to investigate the effect of calcium phosphate containing desensitizing pretreatments on the microtensile bond strength (MTBS) and microleakage of the multimode adhesive agent to dentin. MATERIALS AND METHODS: In this study, twelve noncarious, freshly extracted human third molar teeth for MTBS and 20 premolar teeth for the microleakage test were used. The teeth were restored using Clearfil Universal Bond + Clearfil APX and Teeth mate Desensitizer (TMD). For MTBS test, Group 1: Self-etch, Group 2: Etch and rinse (G1 and 2, nondesensitizer treatment served as a control), Group 3: TMD/self-etch, Group 4: Acid-etch/TMD/etch and rinse. For microleakage test, Class V adhesive cavities (3 mm × 2 mm × 2 mm) were prepared and restored as mentioned before. The restored teeth were subjected to thermal cycling. The MTBS test was performed in all procedures. The MTBS data were submitted to a one-way ANOVA and post hoc Tukey test (P P Results: Control groups exhibited a higher mean MTBS value than TMD groups, and there were statistical differences between the groups. TMD groups also demonstrated significantly less microleakage than control groups (P Conclusions: This study proves that the application of TMD with a multimode adhesive bonding system produced significantly lower MTBS and microleakage.

Effect of QMix irrigant on the microhardness of root canal dentine.

BACKGROUND: The aim of this study was to evaluate the effects of QMix, EDTA + CHX, EDTA + NaOCl and maleic acid on the microhardness of root canal dentine. METHODS: Forty recently extracted human maxillary canine teeth were longitudinally sectioned into 80 segments and then embedded in an autopolymerizing acrylic resin. The microhardness of the dentine in the specimen was measured with a Vickers diamond indenter at the coronal, middle and apical thirds of the roots. Finally, the specimens were divided randomly into four groups: 17% EDTA + 2.5% NaOCl; 17% EDTA + 2% CHX; QMix; and 7% maleic acid. Post-treatment microhardness values were obtained and the decrease in microhardness was calculated as a percentage. Microhardness values were statistically analysed using the Kruskal-Wallis and Mann-Whitney U tests. RESULTS: Maleic acid significantly decreased microhardness in all regions, compared to the other groups. In the coronal and middle regions, there was no significant difference among the other groups. In the apical region, there was no significant difference between QMix and 17% EDTA + 2% CHX but these groups presented significant dentine microhardness reduction compared to the 17% EDTA + 2.5% NaOCl group. CONCLUSIONS: While maleic acid showed the greatest reduction in dentine microhardness, it was found that QMix, 17% EDTA + 2% CHX and 17% EDTA + 2.5% NaOCl cause the same reduction in the microhardness of root canal dentine in the coronal and middle regions.

Fracture resistance of the buccal cusps of root filled maxillary premolar teeth restored with various techniques.

AIM: To compare the cusp fracture resistance of teeth restored with composite resins and two post systems. METHODOLOGY: Eighty extracted single-rooted human maxillary premolars were randomly assigned to eight groups (n = 10). Group 1 (control) did not receive any preparation. From groups 2 to 8, the teeth were root filled and mesio-occluso-distal (MOD) cavities were prepared. Group 2 remained unrestored. Group 3 was restored with packable resin composite using a single-step adhesive. Group 4 was restored with packable resin composite using a single-step adhesive and a thin layer of flowable resin composite. Group 5 was restored with packable resin composite using a total-etch two-step adhesive. Group 6 was restored with ormocer resin composite using a total-etch two-step adhesive. Group 7 was restored with an endodontic glass fibre post and hybrid resin composite using a total-etch two-step adhesive. Group 8 was restored with an endodontic zirconium post and hybrid resin composite using a total-etch two-step adhesive. The teeth were then mounted in a universal testing machine, the buccal cusp loaded (30 degrees ) until fracture, and the data analysed statistically. RESULTS: Group 1 had the greatest fracture resistance, and group 2 the poorest. Groups 5-8 had significantly greater (P < 0.05) fracture resistance than groups 3 and 4. No significant differences were found between groups 3 and 4, or amongst groups 5-8 (P > 0.05). CONCLUSIONS: For root filled maxillary premolars with MOD cavities, adhesive resin composite restorations, with and without glass and zirconium posts, increased the fracture resistance of the buccal cuSPS. A total-etch two-step adhesive increased significantly fracture resistance more than a one-step adhesive. For the one-step adhesive, an additional layer of flowable resin composite did not enhance fracture resistance.

In vitro fracture resistance of root-filled teeth using new-generation dentine bonding adhesives.

AIM: To compare the fracture resistance of root-filled premolar teeth restored with new-generation dentine bonding adhesives. METHODOLOGY: Sixty extracted single-rooted human maxillary premolar teeth were used. Access cavities were prepared, and the roots were instrumented with K-files to an apical size 50 using a step-back technique. Root fillings were accomplished using gutta percha (Sure-Endo, Seoul, Korea) and AH Plus root canal sealer (Dentsply DeTrey, Konstanz, Germany) using the lateral condensation technique. The teeth were then randomly divided into six groups of 10 teeth each. A mesiodistocclusal (MOD) cavity was prepared in the teeth to the level of the canal orifices so that the thickness of the buccal wall of the teeth measured 2 mm at the occlusal surface and 3 mm at the cemento-enamel junction. Preparations were restored using the following adhesive systems: Etch & Prime 3.0 (Degussa AG, Hanau, Germany), Clearfil SE Bond (Kuraray, Osaka, Japan), Prompt L-Pop (ESPE, Seefeld, Germany), Panavia F (Kuraray, Osaka, Japan), Optibond Plus (Kerr, Orange, CA, USA) and Admira Bond (Voco, Cuxhaven, Germany); all preparations except those of the Panavia F and Admira Bond groups were further restored with resin composites. The Panavia F group was restored with amalgam and the Admira Bond group with Ormocer (Voco, Cuxhaven, Germany). The teeth were mounted in a Universal Testing Machine (Hounsfield, Surrey, UK), and the buccal walls were subjected to a slowly increasing compressive force until fracture occurred. The force of fracture of the walls of each tooth was recorded and the results in the various groups were compared. Statistical analysis of the data was accomplished using one-way anova. RESULTS: There was no significant difference in the fracture resistance of any of the test groups. CONCLUSIONS: In this laboratory study, the type of dentine bonding agents had no influence in the fracture resistance of teeth.