Effects of attachment type and palatal coverage on oral perception and patient satisfaction in maxillary implant-supported complete denture patients.

AIM: The effect of oral rehabilitation on the oral perception of implant-supported overdenture patients is a concern. This study evaluated the effects of the attachment type and palatal coverage on oral perception and patient satisfaction in maxillary implant-supported complete denture patients. SUBJECTS AND METHODS: The correlation between oral perceptual ability (OPA) and patient satisfaction in three groups was investigated. Group I consisted of dentate individuals (n = 40), Group II consisted of maxillary implant-supported complete denture patients with bar attachments and palatal coverage (n = 12), and Group III of maxillary implant-supported complete denture patients with magnetic attachments and palatal coverage (n = 14). In addition, implant-supported maxillary overdentures with bar attachments, with (Group II; n = 12) and without (Group IV; n = 18) palatal coverage, were examined in terms of patient satisfaction and OPA. The relationship between OPA and patient satisfaction was assessed with the Turkish version of the Oral Health Impact Profile-14 (OHIP-TR-14) satisfaction survey. To compare oral sensory function among the groups, tactile awareness and pressure awareness were assessed. RESULTS: There was no significant difference in OHIP-TR-14 scores between Groups II and III. In addition, there was no correlation between oral tactile function and patient satisfaction in Groups II and III. For patients with maxillary bar-retained implant-supported overdentures, palatal coverage did not affect the correlation between OPA and patient satisfaction, lateral pressure threshold, or tactile thickness threshold. CONCLUSION: According to the results of the study, whether maxillary implant-supported overdentures were made with a bar- or magnetic-type retainer, and whether bar-retained implant-supported overdentures had an open or closed palate did not affect the correlation between patient satisfaction and oral perception.

Effect of chitosan on sealer penetration into the dentinal tubules.

OBJECTIVE: The objective of this study is to compare the effectiveness of final irrigation with chitosan, ethylenediaminetetraacetic acid (EDTA), and citric acid (CA) on a resin-based sealer (AH plus sealer [Dentsply DeTrey, Konstanz, Germany]) penetration into dentinal tubules using confocal laser scanning microscopy. MATERIALS AND METHODS: Seventy recently extracted human mandibular premolars were instrumented and irrigated with sodium hypochlorite (NaOCl), then divided into four groups according to the final irrigation regimen used: (1) the EDTA group: 17% EDTA + 2.5% NaOCl, (2) the CA group: 10% CA + 2.5% NaOCl, (3) the chitosan group: 0.2% chitosan + 2.5% NaOCl, and (4) the control group: 2.5% NaOCl. All teeth were obturated using the cold lateral condensation technique with gutta-percha and AH Plus sealer labeled with fluorescent dye. The apical 2 mm of specimen was discarded, and slices were obtained for apical, middle, and coronal thirds of the root with 1 mm intervals. Maximum, mean, and percentage of sealer penetration (SP) inside tubules were measured using confocal laser scanning microscopy. RESULTS: The percentage of SP was significantly higher in chitosan, EDTA, and CA group than control group for coronal thirds (P < 0.05), whereas there was no significant difference among all groups for middle and apical thirds. Chitosan and EDTA showed increased mean values of SP depth for middle thirds (P < 0.05). In all sections, the maximum depth of SP was significantly lower in EDTA group than other groups (P < 0.05). CONCLUSIONS: Chitosan, EDTA, and CA significantly improved the percentage of SP for coronal thirds.

Efficacy of manual and mechanical instrumentation techniques for removal of overextended root canal filling material.

OBJECTIVE: To compare the efficacy of manual and mechanical instrumentation techniques, including ProTaper Universal retreatment system, Mtwo retreatment system, Reciproc system, and Hedström files, regarding removal of overextended root canal filling material. MATERIALS AND METHODS: Eighty extracted human mandibular premolar teeth were prepared at the apical foramen level using Revo-S rotary files and subsequently obturated. The root canal filling material was deliberately extruded from the apex. Samples were transferred to glass vials that simulated the periapical area. Eighty samples of overfilled teeth were randomly assigned to four equal groups (n = 20) for removal of the root filling material with ProTaper Universal retreatment files (Group 1), Mtwo retreatment files (Group 2), Reciproc system (Group 3), and hand files (Group 4). Removal of the root canal filling material and additional preparation were performed by individual instruments from each different system up to a #40 size. The external apical surface of the teeth and the surrounding glass vials were checked using a dental operation microscope with ×12.5 magnification. Samples were divided into two groups based on whether removal of the overextended root canal filling material was successful or not. The Fisher's exact test was used to detect any significant difference between the groups (α = 0.05). RESULTS: The success rate for removal of overextended gutta-percha was greater for the Mtwo (30%) and hand files (30%) compared with the ProTaper (20%) and Reciproc (10%). However, no significant statistical differences existed among the experimental groups (P > 0.05). CONCLUSIONS: This study demonstrated that all tested systems had similar efficacy in removing overextended root canal filling material.

Efficacy of different irrigation techniques in the removal of calcium hydroxide from a simulated internal root resorption cavity.

AIM: To evaluate the efficacy of six irrigation techniques to remove calcium hydroxide (CH) from a simulated internal root resorption cavity. METHODOLOGY: The root canals of 100 single-rooted teeth were prepared using the ProTaper system to size F5. The roots were split longitudinally, and standardized simulated internal root resorption cavities were prepared in the two root halves. The root halves were reassembled, and CH was placed into the root canals, with the exception of five teeth that served as the negative control group. Another five teeth (the positive control group) were not subjected to the CH removal procedure. Ninety teeth were randomly divided into six experimental groups (n = 15), according to the final irrigation techniques used: conventional syringe irrigation (CSI), CanalBrush (CB), passive ultrasonic irrigation (PUI), self-adjusting file (SAF) system, EndoActivator (EA), and apical negative pressure irrigation (EndoVac system). Five millilitres of 3% NaOCl and 17% EDTA were used in all experimental groups during the CH removal procedure. The amount of remaining CH was evaluated under a stereomicroscope at 20 ×magnification, using a 4-grade scoring system. The data were statistically compared using the Kruskal-Wallis and Mann-Whitney U-tests (P < 0.05). RESULTS: Remnants of CH in simulated internal root resorption cavities were found in all experimental groups. SAF and PUI were superior to the other groups (P < 0.05); however, there was no significant difference between the SAF and PUI (P > 0.05). There were also no significant differences between the CSI, CB, EA and EndoVac groups (P > 0.05). CONCLUSIONS: None of the irrigation techniques was able to completely remove CH from a simulated internal root resorption cavity.

The effect of reciprocation versus rotational movement on the incidence of root defects during retreatment procedures.

AIM: To compare the incidence of dentinal defects caused by reciprocating and rotary techniques during retreatment procedures. METHODOLOGY: One hundred and twenty extracted mandibular premolars with single canals were selected. Twenty teeth were left unprepared. The root canals in the remaining 100 teeth were prepared with K-files up to size 35 and filled with Gutta-percha and AH Plus sealer using a passive cold lateral compaction technique. Twenty canals were filled and received no further treatment. Eighty teeth were divided into four groups (n = 20 in each) to undergo the removal of the root filling. In groups 1 and 2, the root filling was removed using ProTaper Retreatment files and Reciproc files, respectively, and the canals were not refilled. In groups 3 and 4, the root filling was removed using ProTaper Retreatment files and Reciproc files, respectively, and the canals were then refilled using a conventional cold lateral compaction technique. The roots were sectioned horizontally at 3, 6 and 9 mm from the root apex and observed under a stereomicroscope at 20× magnification. Defects were categorized as no defect, incomplete defect and fracture. The differences between the groups were analysed using the chi-square exact test (P = 0.05). RESULTS: No defects were observed in the unprepared and filled groups, in contrast to the experimental groups. In the coronal thirds, groups 2 and 4 had more dentinal defects than groups 1 and 3 (P < 0.05). In the middle thirds, group 4 had more defects than group 1 (P < 0.05). In the apical thirds, group 2 had fewer defects than did group 3 and group 4. Also, group 3 had more defects than group 1 (P < 0.05). When comparing the experimental groups, there were no significant differences with regard to fracture (P > 0.05). CONCLUSIONS: Both nickel-titanium systems were associated with dentinal defects during retreatment procedures in extracted premolar teeth.

The bond strength of endodontic sealers to root dentine exposed to different gutta-percha solvents.

AIM: To evaluate the effects of various gutta-percha solvents on the push-out bond strength of several root canal sealers on root dentine. METHODOLOGY: The root canals of 210 single-rooted human teeth were prepared with the ProTaper System (Dentsply Maillefer, Ballaigues, Switzerland) up to a master apical file size of F4, and the following variables evaluated for bond strength: solvent type (chloroform, eucalyptol and orange oil), time (2 and 5 min), sealer type (AH Plus, MTA Fillapex and Sealapex) and root thirds (coronal, middle and apical). After canal filling, three 1-mm-thick slices were obtained from each root sample, and the bond strength of the test materials was measured using a push-out test set-up at a cross-head speed of 1 mm min(-1) . The data were analysed using four-way factorial anova (P = 0.05). RESULTS: Bond strength was significantly affected by solvent type and time (P < 0.001). The use of chloroform for 5 min in the root canal decreased bond strength of all sealers (P < 0.001). Eucalyptol and orange oil did not affect the bond strength of the sealers (P > 0.05). In all conditions, the push-out bond strength was highest for AH Plus and lowest for MTA Fillapex (P < 0.001). Bond strength values decreased in a corono-apical direction in all groups (P < 0.001). CONCLUSIONS: Chloroform used for 5 min during retreatment decreased the bond strength of AH Plus, Sealapex and MTA Fillapex to root dentine.

Membranoproliferative glomerulonephritis and a rare bleeding disorder: Factor X deficiency.

Factor X (FX) deficiency is a rare hereditary coagulation disorder. This is the first case report on the association of FX deficiency and membranoproliferative glomerulonephritis (MPGN) type I. The patient, a 17-year-old male, presented with edema, hypertension, and microscopic hematuria, followed by a mild upper respiratory tract infection. Laboratory tests revealed: serum creatinine 1.6 mg/dl, serum albumin 2.80 g/dl, C3 16 mg/dl and proteinuria (1,800 mg/day). The renal biopsy showed MPGN type I. The coagulation profile prior to percutaneous renal biopsy revealed prolonged prothrombin time and activated partial thromboplastin time values. The patient was given fresh frozen plasma and vitamin K before the biopsy. Further evaluation showed the functional activity of FX was 7% of the norm. This case emphasizes the need for routine coagulation screening before percutaneous renal biopsy.

Evaluation of the effects of restorative materials used for occlusal surfaces of implant-supported prostheses on force distribution.

In this study, the functional stresses in alveolar bone created by restorative materials used in implant-supported prostheses were determined by the photoelastic stress analysis method. A photoelastic resin mandibular model, hollow-cylinder implants (3.5 mm diameter, 10 mm length), and fixtures and superstructures made of five different prosthetic materials were used. Vertical and 45-degree inclined loads were applied to the model. Subsequently, color photographs of the force line distribution observed on a polariscope were taken. Differences between vertical and inclined loads were statistically significant for all prosthetic materials (P < 0.01). The greatest stress distribution around the apex of the implant was observed with Ceramco II porcelain, followed by Biodent acrylic. The ArtGlass and Elcebond CCV composite materials had equal values, whereas Verebond Ni-Cr alloy showed minimum stress distribution.