The effect of a new calcium-based agent, Pro-Argin, on the microhardness of bleached enamel surface.

BACKGROUND: This study investigated the effects of Pro-Argin application on the microhardness of bleached enamel and compared them with those of acidulated phosphate fluoride (APF) and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) applications. METHODS: Forty blocks (4 × 4 × 4 mm) were prepared from the facial surfaces of 10 sound bovine incisors. The enamel surfaces were bleached with 35% hydrogen peroxide three times at 5-day intervals. The specimens were divided into five treatment regimen groups (n = 8 each): Group 1, bleaching/no surface treatment (control); Group 2, bleaching/Pro-Argin toothpaste treatment; Group 3, bleaching/Pro-Argin treatment; Group 4, bleaching/APF treatment; and Group 5, bleaching/CPP-ACP treatment. During bleaching treatments, specimens were stored in artificial saliva. Vickers microhardness measurements were performed at baseline and after treatment in all groups. Statistical analyses were performed using the paired t-test, one-way analysis of variance, and post hoc least significant difference tests. RESULTS: After bleaching, hardness values of enamel surfaces increased significantly in the treatment groups versus the control group (p < 0.05). However, no significant difference was found among treatment groups (p > 0.05). CONCLUSIONS: Through bleaching treatment, Pro-Argin application may have a positive effect on enamel surface hardness, equivalent to that of CPP-ACP or APF.

Root canal treatment of a periradicular lesion caused by unintentional root damage after orthodontic miniscrew placement: a case report.

AIM: To present the successful endodontic management of a maxillary lateral incisor tooth with a periradicular lesion caused by unintentional root damage after orthodontic miniscrew placement. SUMMARY: A 22-year-old female was diagnosed with a skeletal Class II, Division 2 malocclusion with Class II molar and canine relationships on both sides. The treatment plan included distalization of the maxillary first molars bilaterally followed by full fixed appliance therapy. For the maxillary molar distalization, an appliance in conjunction with a miniscrew anchorage system was designed. Two months later, the patient came to the clinic with complaints of pain in the maxillary right lateral incisor region. On intraoral examination, intraoral sinus tracts were detected in the maxillary right buccal sulcus and palate. A large radiolucent lesion with a well-defined margin around the root of the maxillary right lateral incisor was seen. Root canal treatment was performed on the maxillary right lateral incisor tooth. The root canal was filled with gutta-percha and AH Plus sealer, using a lateral compaction technique. The final restoration of the tooth was completed using composite, and the tooth was reviewed after 10 months. The tooth was asymptomatic and radiographically showed repair of the lesion. Healing was achieved without any need for further endodontic or surgical intervention. Key learning points • This case illustrates the need to take care with miniscrews when performing orthodontic treatment, especially when the miniscrews are in close proximity to root apices. • The periradicular lesion as a result of miniscrew damage was successfully treated with root canal treatment.

Efficacy of several techniques for the removal of calcium hydroxide medicament from root canals.

AIM: To compare the efficacy of several techniques for the removal of calcium hydroxide (Ca(OH)(2)) from root canals. METHODOLOGY: The root canals of 24 freshly extracted human mandibular premolars were prepared with ProTaper rotary instruments. The teeth were sectioned longitudinally along the length of the instrumented canals. The roots were subsequently reassembled with wires. After Ca(OH)(2) was placed into the canals, four techniques were used for its removal. In Group I, the teeth were irrigated with 5 mL of 2.5% NaOCl. Group II was treated in the same manner as Group I, but 5 mL of 17% EDTA was used in addition to NaOCl. In Group III, the teeth were irrigated with 5 mL of 2.5% NaOCl and agitated by an ultrasonic unit. In Group IV, the teeth were irrigated with 5 mL of 2.5% NaOCl and a CanalBrush was used to remove the Ca(OH)(2) . The roots were disassembled and digital photographs were taken. Measurements of residual Ca(OH)(2) were performed as percentages of the overall canal surface area. The data was analysed with one-way ANOVA with post hoc Tukey test. RESULTS: Significantly less residual material was obtained with a CanalBrush and passive ultrasonic agitation of NaOCl than the other groups (P < 0.05). There was no significant difference between syringe delivery of NaOCl and NaOCl+EDTA (P > 0.05). CONCLUSIONS: None of the techniques removed the Ca(OH)(2) dressing completely. CanalBrush and ultrasonic agitation of NaOCl were significantly more effective than irrigant-only techniques.

Pain perception during inferior alveolar injection administered with the Wand or conventional syringe.

OBJECTIVE: This study compared a computerised device (the Wand) with a conventional syringe in terms of the pain of needle insertion and injection during inferior alveolar nerve (IAN) block injection. METHODS AND MATERIALS: The subjects were 40 patients between the ages of 18 and 30 years requiring local anaesthesia for dental restoration in the mandible. Before anaesthetic administration, the patients' anxiety levels were determined. Contralateral IAN injections were administrated at two separate appointments with random use of either the Wand or a conventional syringe. Following the injection, the patients used both the pain rating score (PRS) and a visual analogue scale (VAS) to assess the intensity of pain. RESULTS: When pain was measured after the injection, the Wand was found to be less painful than the syringe for the pain of both needle insertion and injection (p <0.05). CONCLUSION: The Wand technique resulted in significantly lower pain scores during the IAN block injections. Most of the patients preferred the IAN injection with the Wand for future dental injections.

Efficacy of three rotary NiTi instruments in removing gutta-percha from root canals.

AIM: To investigate the ability of three rotary nickel-titanium instruments and hand instrumentation to remove gutta-percha and sealer. METHODOLOGY: Sixty freshly extracted human single-rooted teeth, each with one root canal, were instrumented with K-files and filled using cold lateral compaction of gutta-percha and AH Plus (Dentsply Detrey, Konstanz, Germany) sealer. The teeth were randomly divided into four groups of 15 specimens each. Removal of gutta-percha was performed with the following devices and techniques: ProTaper, R-Endo, Mtwo and Hedström files. The specimens were rendered transparent and the area of remaining filling material on the root canal wall was measured using a computer image analysis program. Statistical analysis was accomplished by Kruskal-Wallis and Mann-Whitney U-tests with Bonferroni correction for the analysis of residual root filling material and working time. RESULTS: The ProTaper group had less filling material inside the root canals than the other groups, but a significant difference was found between only the ProTaper and Mtwo groups (P < 0.05). The retreatment time for Mtwo and ProTaper was significantly shorter compared with R-Endo and manual instrumentation with Hedström files (P < 0.001). R-Endo was significantly faster than manual instrumentation (P < 0.001). CONCLUSIONS: Under the experimental conditions, ProTaper left significantly less gutta-percha and sealer than Mtwo instruments. Complete removal of materials did not occur with any of the instrument systems investigated.

Canal preparation with Hero 642 rotary Ni-Ti instruments compared with stainless steel hand K-file assessed using computed tomography.

AIM: To compare ex vivo root canal preparation with conventional stainless steel K-files and Hero 642 rotary Ni-Ti instruments. METHODOLOGY: Mesiobuccal canals of 20 maxillary first molars (with angles of curvature between 25 degrees and 35 degrees ) were used. After preparation with Hero 642 rotary instruments and stainless steel K-files, the amount of transportation that occurred was assessed using computed tomography. The teeth were scanned by computed tomography before instrumentation. One millimetre thick slices were prepared from the apical end point to the pulp chamber. The first two sections were 3 mm from the apical end of the root (apical level) and 3 mm below the orifice (coronal level). A further section (mid-root level) was recorded, dividing the distance between the sections of apical and coronal levels into two equal lengths. Ten teeth were instrumented using Hero 642 rotary instruments and another 10 teeth were instrumented using stainless steel K-files. Following the completion of the instrumentation, the teeth were again scanned and compared with the cross-sectional images taken prior to canal preparation. Amount of transportation and centreing ability was assessed. Student's t-test was used for statistical analysis. RESULTS: Less transportation occurred with Hero 642 rotary instruments than stainless steel K-files at the mid-root and coronal levels (mid-root: P < 0.05 and coronal: P < 0.001). Hero 642 rotary instruments had better centreing ability than K-files at all three levels (apical: P < 0.05, mid-root: P < 0.05 and coronal: P < 0.001). CONCLUSIONS: Hero 642 rotary instruments transported canals less, especially at the middle and coronal thirds of the root canals than stainless steel K-files. Hero 642 instruments had better centreing ability.