The solubility, pH value, chemical structure, radiopacity, and cytotoxicity of four different root canal sealers: an in vitro study.

OBJECTIVE: The aim of this study was to investigate solubility, pH value, chemical structure, radiopacity, and cytotoxicity of AH Plus BC, TotalFill BC, AH Plus, and AH Plus Jet sealers. MATERIALS AND METHODS: Cytotoxicity analysis with direct and extraction tests at 3 different concentrations (1:1, 1:2, 1:4 v/v%) and time (24 h, 48 h, and 72 h) on Saos-2, PdLF, and THP-1 cell lines, chemical structure with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analysis, solubility, pH, and radiopacity values of AH Plus BC, TotalFill BC, AH Plus, and AH Plus Jet were evaluated. For statistical analyses of the groups, repeated measures, factorial, and one-way ANOVA tests were used. The statistical significance level was set at p < .05. RESULTS: Resin-based sealers showed higher cytotoxicity values than the bioceramic-based sealers (p < 0.05). Time and concentrations were effective on the cell viabilities for cell lines. Higher peaks of calcium were detected bioceramic-based sealers and higher amount of zirconium was detected in AH Plus BC (p < 0.05). AH Plus BC showed similar radiopacity value with AH Plus, AH Plus Jet, whereas TotalFill BC showed the lowest radiopacity (p < 0.05). Bioceramic-based sealers had higher pH values in all experiment periods, and the difference between resin- and bioceramic-based sealer groups was significant (p < 0.05). However, the solubility values of the tested root canal sealers revealed no differences (p > 0.05). CONCLUSIONS: The newly produced AH Plus BC Sealer showed similar properties with TotalFill BC, and their biological properties were better than AH Plus and AH Plus Jet. CLINICAL RELEVANCE: AH Plus BC could be a possible alternative to other bioceramic- or resin-based sealers.

A novel soft tissue thickness measuring method using cone beam computed tomography.

OBJECTIVE: The aim of this study was to introduce a novel soft tissue thickness measurement method using cone beam computed tomography (CBCT) and to compare the new method with ultrasonic device applications and transgingival probing measurements. METHODS: Twenty-five participants (12 female, 13 male, age range, 25-51 years) were included the study. Soft tissue thickness in lateral incisor, canine, premolar, and molar regions were measured using transgingival probing (group T), ultrasonic device (group U), and CBCT scan measurements (group C). Differences and correlations between groups and agreement between measurement methods were evaluated. RESULTS: Soft tissue thickness was significantly lower in group U in premolar region, but was significantly higher in molar region compared with group C and group T (P < .05). There were significant positive correlations in lateral incisor and canine region, between group U and group C, in premolar region between group T and group C, and in molar region between group U and group C, and between group C and group T (P < .05). The highest agreement between measurement methods was evident between group T and group C. CONCLUSION: Soft tissue thickness values in maxilla may differ depending on the measurement method and location of the measurement. Ultrasonic device, transgingival probing, and CBCT measures may not necessarily correlate in all locations. The high agreement between CBCT measurements and transgingival probing may suggest the newly introduced method as a promising technique for soft tissue thickness evaluation. CLINICAL SIGNIFICANCE: This study evaluated the relation between different soft tissue thickness measurement methods and demonstrated a novel method which can be used in any part of the mouth. The outcome also suggested that the measurement method and the location might affect the soft tissue thickness value obtained, and therefore might be important in clinical decision making.

Prognostic factors in direct pulp capping with mineral trioxide aggregate or calcium hydroxide: 2- to 6-year follow-up.

OBJECTIVES: The aim of this retrospective study was to evaluate the influence of various predictors on healing outcomes after direct pulp capping (DPC) using either mineral trioxide aggregate (MTA) or calcium hydroxide (CH) as a pulp-dressing agent. MATERIALS AND METHODS: The present study included 172 mature asymptomatic permanent teeth with carious-exposed pulp. The teeth were treated with DPC, using either MTA or CH, and the treatment outcome was evaluated clinically and radiographically. The effect of potential clinical variables on the treatment outcome of DPC was evaluated clinically and radiographically during a 24-72-month follow-up. In order to assess the cumulative successes of CH and MTA after DPC, Kaplan-Meier survival analysis and log-rank test was used. The subgroups were compared by means of the log-rank test. Also, univariate Cox regression analysis was used to determine hazard ratio of clinical variables. RESULTS: One hundred and fifty-two teeth of 172 capped teeth were available for follow-up, with an overall recall rate of 87.6 % for MTA vs 89.3 % for CH. The mean period of follow-up was 37.3 (±17.2) months. Overall success rates of 85.9 and 77.6 % in the MTA and CH groups were observed, respectively. The cumulative success rate of both materials was not statistically different when analysed by the Cox proportional hazard regression analysis (P = 0.282). The Kaplan-Meier survival curves revealed that 2-year overall pulp survival was 91.4 %, while the 4- and 6-year survival rates were 84 and 65 %, respectively. None of the clinical variables had a considerable influence on the outcome of DPC (p > 0.05). CONCLUSIONS: MTA-capped teeth demonstrated a slightly higher success rate than CH, revealing that it can be recommended as a reliable direct pulp-capping material. None of the clinical variables investigated significantly affected posttreatment healing. CLINICAL RELEVANCE: DPC with MTA is a straightforward procedure with favourable outcome of 24- to 72-month follow-ups in vital mature asymptomatic permanent teeth with cariously exposed pulp, and it may be considered a realistic alternative therapy to RCT.

Glass-ceramics bonding in geriatric patients: comparison with young teeth.

OBJECTIVE: The aim of the study was to assess whether in geriatric patients, the shear bond strength (SBS) of glass-ceramics differed when compared to young controls. BACKGROUND: In the need of aesthetic restorations for geriatric patients, reliable bonding of glass-ceramics should be accomplished; however, glass-ceramics bonding on aged tooth structures is still unclear. MATERIALS AND METHODS: Sixty extracted molars from young and geriatric patients [18-25 (Y), and 65-80 (O)] were cut buccolingually to prepare enamel (E) and dentin (D) surfaces. Both surfaces were randomly divided into three groups according to the resin cements: Variolink II (V); Superbond (S); and Clearfil Esthetic Cement (C) (n = 10). Disc-shaped glass-ceramics (IPS E-max Press) (n = 120) were prepared. Specimens were bonded and subjected to thermocycling. SBS test was performed using a universal testing machine (0.5 mm/min). After debonding, the surfaces were examined using stereomicroscope and scanning electron microscope. Data were statistically analysed with Kolmogorov-Smirnov, Levene, anova and Bonferroni tests (p = 0.05). RESULTS: There were no significant differences between the old and young teeth surfaces. V showed the highest SBS [MPa(SD)] on both enamel and dentin [36.7 (6.5) (YE), 23.2 (13.2) (YD), 32.1 (16.2) (OE), 25.5 (8.6) (OD), respectively]. Significant differences were observed between resin cements (p < 0.05). The failure types were 43% adhesive between tooth and cement, 48% mix, 9% adhesive between cement and ceramic, regardless of cement type. CONCLUSION: In geriatric patients, the shear bond strength of glass-ceramics did not differ when compared to that of young controls. On the dentin surface, etch-rinse resin cements appear to be more appropriate for glass-ceramics bonding.

Radiopacity of Esthetic Post Materials: Evaluation with Digital Analysis Technique.

PURPOSE: To evaluate the radiopacity of five post materials using a digital image analysis method. MATERIALS AND METHODS: Twelve specimens from each post type (two zirconia and three fiber based) of 2 mm in thickness were obtained using a diamond blade mounted on a cutting machine, and digital radiographs were taken along with aluminum step-wedge and dentin discs under standard exposure conditions. The mean gray-values of specimens were measured using a computer graphics program. Data were analyzed using one-way ANOVA followed by Holm-Sidak multicomparison test (p = 0.05). RESULTS: The highest radiopacity was observed in custom zirconia (5.842 millimeters of equivalent Al [mmAl]), and the lowest value was detected with FRC-Postec (Ivoclar Vivadent) (1.716 mmAl). Significant differences were revealed between the radiopacity values among all groups (p < 0.05), except the Zr post materials (p = 0.56). CONCLUSIONS: All tested post materials had higher radiopacity than dentin. Further studies will be required to clarify optimum radiopacity properties of the post materials to provide a precise clinical observation.

The characteristics and occurrence of the talon cusps in Turkish population: a retrospective sample study.

PURPOSE: The purpose of this study was to figure out the characteristics and occurrence of talon cusps in a sample of Turkish population. METHODS: In this retrospective study, talon cusps in permanent dentition were evaluated on radiographs and intraoral photographs which were obtained from patients who were referred to Oral and Maxillofacial Radiology Department, Faculty of Dentistry, Adnan Menderes University, Aydin, Turkey between January 2013 and January 2014. RESULTS: Talon cusps were observed in 365 of 4116 patients, with a frequency of 8.86 %. There were 208 (57 %) females and 157 (43 %) males with this variation. Maxillary canines were the most affected anterior teeth (40.83 %), followed by lateral incisors (39.60 %) and central incisors (19.55 %). Of the patients, 81 (22.19 %) had type I talon cusp with two periapical pathologies, 114 (31.23 %) had type II talon cusp with four periapical pathologies and 226 (61.91 %) had type III talon cusp with also four periapical pathologies. CONCLUSIONS: The occurrence of talon cusps was higher than other studies reported in the literature, with an exception of the study in Alaskan Eskimos. The most commonly detected type of talon cusp was type III (61.91 %), and dens invaginatus was the most frequent variation observed with talon cusps.

Appropriate and necessary oral care for people with cancer: guidance to obtain the right oral and dental care at the right time.

PURPOSE: The identification of experienced and knowledgeable dental specialists to provide appropriate oral care for cancer patients, as well as the integration of this care within general oncology management, may be a challenge. This paper discusses the general and additional requirements for dental care providers to support the cancer patient and provide prevention and/or treatment for oral complications of cancer therapy. METHODS: We performed a literature review of specific issues regarding the oral cavity and adjacent structures in the cancer patient, including detection and early diagnosis of oral malignancy. We incorporated the systemic effects of cancer and its therapy that affect oral disease and treatment. We present a summary of how to seek expert dental care for cancer patients and for referral from the dental and medical community. RESULTS: Due to the complexity conferred by the disease and its treatment, cancer patients require educated, experienced dentists for treatment and/or prevention of oral-related morbidity. Correct diagnosis and evidence-based prophylactic and therapeutic oral care can significantly improve patient quality of life and reduce morbidity and healthcare costs. CONCLUSIONS: The knowledge and expertise of dental professionals regarding prevention/treatment of complications and secondary malignant lesions in cancer patients are critical. Integration of oral care with the oncology care and in survivors requires effective communication between dental and medical providers beginning ideally at diagnosis. These clinicians may be identified at the cancer center, nearby hospital dental programs, and, less commonly, in the community.

Cytotoxicity of dentin bonding agents.

This study sought to evaluate the cytotoxicity of 5 dentin bonding agents (Admira Bond, Adper Single Bond Plus, Clearfil SE Bond, Clearfil S3 Bond, and Heliobond) by XTT assay using human gingival fibroblast cells. Samples of dentin bonding agents were prepared on a black 96-well microplate, and the cytotoxicity of each bonding material was measured every 24 hours for 7 days, then on Days 14, 21, and 28. One-way ANOVA and Bonferroni post hoc tests were used for statistical analyses. All 5 materials were evaluated as severely cytotoxic (P < 0.001) on the first day, with cell viabilities ranging from 6% to 24%. All the bonding agents showed severe cytotoxicity with viability results <10%. With the exception of Adper Single Bond Plus, toxicity continued to Day 28 for all compounds. The utmost care must be considered during the clinical utilization of dentin bonding agents to keep them within the area of restoration and prevent their contact with adjacent tissues.

Dental students' knowledge of characteristics and management of oral complications of cancer therapy.

OBJECTIVE: The aim of this study is to investigate the level of Turkish senior dental students' knowledge regarding the orodental complications and their treatment methods of cancer patients. STUDY DESIGN: A 15-item questionnaire which was obtained from National Institute of Dental and Craniofacial Research that contained information about the orodental complications of the cancer therapy and the dentists' role to provide their treatment protocols was used. Seventy-seven senior dental students answered the questionnaire and the replies were analyzed with stratified and logistic data analyses. RESULTS: Overall, correct replies ranged from 5.2 to 98.7 %. The students knew the basic knowledge of the complications of cancer therapy; however, they failed to answer to the questions (ranging between 1.3 and 94.8 %) about the required clinical practices. The respondents preferred not to answer the questions about the prophylactic measures dentist shall take during a precancer treatment oral evaluation (9.1 %), management of pain in cancer treatment (6.5 %), and necessary considerations before a dental procedure in a chemotherapy patient (3.9 %). The multiple logistic regression analysis revealed that gender had no statistically significant effect on the correct or false answers to the questions (p > 0.05). CONCLUSION: Our results disclosed that dental students' knowledge about oral complications of cancer therapy and the modalities to manage these complications vary. Reevaluation of current undergraduate curricula and continuing education for graduates might address the gaps identified and an educational program about oral and dental management of patients who are to receive/receiving/have received cancer therapy can be prepared and augmented into dental curriculum.

A support vector machine-based algorithm to identify bisphosphonate-related osteonecrosis throughout the mandibular bone by using cone beam computerized tomography images.

OBJECTIVE: This study aimed to develop an algorithm to distinguish the patients with bisphosphonate-related osteonecrosis of the jaws (BRONJ) from healthy controls using CBCT images by evaluating both trabecular and cortical bone changes through the whole body of the mandibular bone. METHODS: Patient data set was created from axial CBCT images of 7 BRONJ patients (28 slices) and 8 healthy controls (27 slices). The healthy bone of healthy controls, bone sclerosis of BRONJ patients, bone necrosis of BRONJ patients, and normal appearing bone of BRONJ patients (NBP) were labeled on CBCT images by three maxillofacial radiologists. Proposed algorithm had preparation and background cancellation, mandibular bone segmentation and centerline determination, spatial transformation of gray values, and classification steps. RESULTS: Significant differences between the statistical moments (mean, variance, skewness, kurtosis, standard error, median, mode and coefficient of variance) of healthy and diseased (bone sclerosis and necrosis) groups were observed (p = 0.000, p < 0.05). Also, variations were noted between healthy controls and NBP of BRONJ patients (p = 0.000, p < 0.05).The statistical moments were utilized to develop the algorithm which has resulted with accuracy of 0.999, sensitivity of 0.998, specificity of 0.998, precision of 1, recall of 0.998, AUC of 1, and F1 score of 0.999 in identification of BRONJ patients from healthy ones. CONCLUSION: The proposed algorithm differentiated the mandibular bones of the healthy and the BRONJ patients with high accuracy in the present test sample.

Is It Time to Consider Implementation of Telemedicine in Current Oral Health Care Services?

Telemedicine offers an excellent opportunity to provide continuing health care for those in need during local/global pandemics and disasters. It provides a safe and effective communication tool between health professionals and can be used as "forward triage" to manage medical/dental emergencies and to minimize the contact between the patients and clinicians during the coronavirus disease (COVID-19) pandemic. Patients with noncommunicable diseases, like cancer, diabetes, cardiovascular, or chronic respiratory diseases, may present with critical health problems due to less access to health care systems during global disasters; opportunities for screening oral mucosa might be significantly disrupted, leading to delayed diagnosis of malignant/potentially malignant lesions. Telemedicine and oral health care associated mobile applications should be implemented to provide equal access to care, to eliminate unnecessary visits to health centers, and to improve practical coordination between professionals and health facilities.

Quality of root canal treatment performed by undergraduate students using nickel-titanium reciprocating versus hand instruments.

PURPOSE: To compare the technical quality of root canal treatment (RCT) depending on the incidence of procedural errors performed by undergraduate students using nickel-titanium reciprocating and conventional hand instrumentation techniques, and to assess the impact of case difficulty and localization of the teeth (maxillary or mandibular molars). METHODS: Dental records and periapical radiographs of molars that were treated with either hand or reciprocating WaveOne (WO) instruments were evaluated retrospectively. The technical quality of RCTs, the incidence of ledge formation, perforation, instrument fracture, overinstrumentation, underfilling, overfilling, inadequate root canal filling, and the effects of case difficulty and tooth localization were compared using the chi-square test with a significance of 5% (α = 0.05). RESULTS: While overinstrumentation was more frequent in the WO group (247 teeth), the incidence of inadequate root canal fillings was higher in the hand instrumentation group (245 teeth) (p < 0.01). No significant difference was observed in the incidence of other procedural errors (p > 0.05). The number of teeth with acceptable technical quality in preparation and obturation was 172 (69.6%) in the WO group, whereas it was 142 (58%) in the hand instrumentation group, presenting a significant difference between the instrumentation techniques (p < 0.01). Higher technical quality rates were observed with WO instrumentation in the high difficulty category and in maxillary teeth (p < 0.01). CONCLUSION: Higher technical quality in preparation and obturation can be achieved with WO reciprocating instruments and file-matched greater tapered gutta-percha cones. No significant difference was observed between the groups in the incidence of procedural errors except for overinstrumentation and insufficient root canal filling. WO instrumentation and obturation with file-matched greater tapered gutta-percha cones provided better technical quality in the high difficulty category and in maxillary teeth.

YouTube™ as an information source for regenerative endodontic treatment procedures: Quality and content analysis.

BACKGROUND: Regenerative endodontic procedures (REPs) are one of the most important developments in dental practice, and in the era of Covid 19 pandemic, audio-visual contents of YouTube™ could be an information source for dental students, practitioners and patients. The aim of this study was to evaluate the quality, content and the demographics of YouTube™ videos about REPs. METHODS: A search on YouTube™ was performed for REPs using "endodontic regeneration", "pulp regeneration", "regenerative endodontics", "regenerative endodontic procedures", "revascularization" and "revitalization" keywords. Totally 531 videos were found and 60 videos met the inclusion criteria. Following the assessment of the demographic features of the videos and the viewing rate of the videos were calculated. The content of the videos was evaluated based on the selected headings. The quality of the videos was assessed using the video information, quality index (VIQI), Global Quality Score (GQS) and DISCERN. The statistical analysis was performed using Spearman Correlation and linear regression analysis. RESULTS: Majority of the videos about REPs were created by dental professionals (91.7%). The most commonly covered topic was "clinical application" (76.7%). Total content score showed a positive correlation with total VIQI (r = 0.795; p < 0.001) and GQS (r = 0.952; p < 0.001). There were significant relationships between total content score, duration, GQS, total VIQI score and DISCERN. CONCLUSION: The findings revealed that YouTube™ videos about REPs provide predominantly clinical information about patient chairside practice of REPs and they could be considered as a supplementary information source for dental students and practitioners.

Energy-Dispersive X-Ray Spectrometry Analysis and Radiopacity of Five Different Root Canal Sealers.

Root canal sealers should have optimum adhesion to the root dentin, low cytotoxicity, sufficient radiopacity and high dimensional stability, which depend mainly on their chemical composition. The aims of this study were to evaluate the chemical composition of Syntex (Cerkamed, Stalowa Wola, Poland), Adseal (Meta Biomed, Cheongju-si, Korea), Sealapex (SybronEndo, Scafati, Italy), MTA Fillapex (Angelus, Londrina, Brazil) and GuttaFlow Bioseal (Coltene/Whaledent, Altstätten, Switzerland) and to determine their radiopacity comparatively. Stainless steel molds with an inner diameter of 5 mm and a depth of 2 mm were constructed. Tested root-canal sealers were mixed and poured into the molds. Following setting, digital periapical radiographs of the specimens (n=12) were taken under standard exposure conditions and the mean gray-values of specimens were measured using a computer graphics program. Then the specimens were examined by scanning electron microscopy, and Energy-dispersive X-ray analysis was performed. The data were analyzed using One-way ANOVA followed by Holm-Sidak multi-comparison test (p = 0.05). Sealapex showed higher calcium peak than MTA Fillapex, GuttaFlow Bioseal, Adseal and Syntex sealers. MTA Fillapex contained a highest amount of tungstate. Sealapex presented the highest radiopacity value among the tested materials (p < 0.05), whereas MTA Fillapex was the least radiopaque material (p < 0.05). Each root canal sealer contains different compositions of radiopacifiers including bismuth oxide, calcium tungstate and zirconium oxide. The tested root canal sealers had radiopacity values above the ISO-specified limit. Sealapex was the most radiopaque root canal sealer followed by GuttaFlow Bioseal, Syntex, Adseal and MTA Fillapex.

Comparative radiopacity of six flowable resin composites.

OBJECTIVE: This study investigated the radiopacity of six commercially available flowable composites by using a digital image analysis method to determine the mean gray values of the materials. METHODS: The flowable resin composites evaluated in this study were Clearfil Majesty Flow, Estelite Flow Q, Tetric N Flow, Esthet X Flow, Filtek Supreme XT Flow and Gradia Direct LoFlo. Ten sample discs (6 x 1 mm) for each group were prepared and 1-mm thick slices were obtained from freshly-extracted teeth for the control group. The mean gray values (MGVs) of each specimen and aluminum (Al) stepwedge were measured by using the histogram function of a computer graphics program. Analysis of variance (ANOVA) was used to investigate the significance of the differences among the groups. For pairwise comparisons, the Tukey test was applied (alpha=0.05). RESULTS: The radiopacity values of Gradia Direct LoFlo, dentin and Estelite Flow Q were close to that of 1 mm Al. Tetric N Flow and Cl Majesty Flow were more radiopaque than enamel, whereas Filtek Supreme XT Flow had a similar radiopacity to enamel. CONCLUSION: The radiopacity of flowable composites varies considerably, and care must be taken when selecting an appropriate material to enable secondary caries detection under posterior composite restorations.

Cyclic Fatigue Resistance of Multiused Reciproc Blue Instruments during Retreatment Procedure.

INTRODUCTION: Root canal retreatment procedure may reduce the mechanical resistance of nickel-titanium instruments and increase the frequency of instrument fracture. The aim of the present study was to evaluate the effect of multiuse of Reciproc Blue R25 instruments on cyclic fatigue resistance during retreatment procedure in mandibular molar teeth. METHODS: Forty-eight Reciproc Blue R25 files were included in the study. In control group, 12 new Reciproc Blue R25 instruments were subjected to cyclic fatigue test by using a stainless steel artificial canal with a 90° angle and 3-mm radius of curvatures. In experimental groups, Reciproc Blue R25 files (n = 12) were used to remove the root canal filling (RCF) material of 1, 2, and 3 molar teeth, respectively. Then cyclic fatigue tests of these 36 instruments were performed. The number of cycles to fracture (NCF) and the length of the fractured fragment were calculated for each instrument. Working time for retreatment procedures was determined in seconds with a digital chronometer. The data were analyzed by using one-way analysis of variance followed by post hoc Tukey test and mixed-effect analysis (P = .05). RESULTS: No significant difference was found between NCF values of new and first time used files (P > .05), but NCF values of new and first time used files were significantly higher than those of second and third time used files (P < .05). The second and third time used files revealed no difference (P > .05). As the number of uses increased, the average time for retreatment procedure statistically extended (P < .05). CONCLUSIONS: Reciproc Blue R25 instrument can be used to remove RCF material of 2 molar teeth. However, because of its decreased NCF values, multiple use over 2 molars may not be suggested.

Benzydamine hydrochloride buccal bioadhesive gels designed for oral ulcers: preparation, rheological, textural, mucoadhesive and release properties.

This study developed and examined the characterization of Benzidamine hydrochloride (BNZ) bioadhesive gels as platforms for oral ulcer treatments. Bioadhesive gels were prepared with four different hydroxypropylmethylcellulose (HPMC) types (E5, E15, E50 and K100M) with different ratios. Each formulation was characterized in terms of drug release, rheological, mechanical properties and adhesion to a buccal bovine mucosa. Drug release was significantly decreased as the concentration and individual viscosity of each polymeric component increased due to improved viscosity of the gel formulations. The amount of drug released for the formulations ranged from 0.76 +/- 0.07 and 1.14 +/- 0.01 (mg/cm2 +/- SD). Formulations exhibited pseudoplastic flow and all formulations, increasing the concentration of HPMC content significantly raised storage modulus (G'), loss modulus (G''), dynamic viscosity (eta') at 37 degrees C. Increasing concentration of each polymeric component also significantly improved the hardness, compressibility, adhesiveness, cohesiveness and mucoadhesion but decreased the elasticity of the gel formulations. All formulations showed non-Fickian diffusion due to the relaxation and swelling of the polymers with water. In conclusion, the formulations studied showed a wide range of mechanical and drug diffusion characteristics. On the basis of the obtained data, the bioadhesive gel formulation which was prepared with 2.5% HPMC K 100M was determined as the most appropriate formulation for buccal application in means of possessing suitable mechanical properties, exhibiting high cohesion and bioadhesion.

Cytotoxicity of Dental Implants: The Effects of Ultrastructural Elements.

PURPOSE: In this in vitro study, the purpose was to assess the cytotoxicity profiles of seven commercial dental implant materials by using cell culture methods on an osteoblastic cell line. MATERIALS AND METHODS: The microstructure of seven commercial dental implants (each given a letter code) was investigated via scanning electron microscopy and energy-dispersive x-ray analysis. Medium extracts were collected on the first and fifth days for each group and tested using MC3T3-E1 cell line. Cytotoxicity was evaluated with Xcelligance System and XTT reagent, and apoptosis was determined by Annexin-V staining. One-way analysis of variance (ANOVA) and Tukey's multiple range tests were used for statistical analyses. In all tests, P was set as .05. RESULTS: ANOVA results disclosed that Ti (P = .001), Na (P = .001), Ca (P = .019), Al (P = .024), and P (P = .020) amounts were significantly different between test materials. Cytotoxicity and apoptosis analyses revealed that implant materials (C) and (E) were the materials with the lowest cell vitality and the highest apoptosis rates among the test materials. Phosphorus was the only element that presented the highest amount in C and E (14.23% and 12.29%, respectively) compared with the other implant materials tested. (F) and (G) had favorable results for all experiments. CONCLUSION: The results suggest that pure dental implant materials with a lower number of additional elements may possess fewer cytotoxic effects than the other implant materials tested in this study.

Radiopacity of Luting Cements as a Potential Factor in Peri-implantitis: An In Vitro Comparative Study.

The aim of this study was to establish the radiopacity of cements used in implant-retained fixed partial dentures with respect to implant material, enamel, and dentin. A sample of 10 specimens of 13 different cements, implants, enamel, and dentin were prepared. Radiographs of the specimens and aluminum step wedges were acquired. Mean gray values of specimens were measured using digital imaging software. Kolmogorov-Smirnov and Shapiro-Wilk normality tests and independent t test were used (P = .05). Implantlink Semi, Premier, and Dentotemp had the lowest radiopacity values; GC FujiTemp LT, Multilink Implant, Poly-F Plus, Cavex-Temporary, and Panavia SA showed the highest. Within the limitations of the study, cements containing zinc oxide and ytterbium-trifluoride can be recommended for cementation of implant-retained restorations.