Demineralized dentin matrix for bone regeneration in dentistry: A critical update.

Over the last few decades, several new materials and techniques have been developed for bone regeneration. Scaffolds based on demineralized dentin matrix (DDM) present an attractive option due to their availability and several animal and human studies have been conducted to ascertain their utility in regenerative dentistry. The aim of this review was to summarize the recent studies conducted on DDM and used for bone grafts. PubMed, Web of Science, and Scopus were used to search for studies published within the last 10 years. The keywords and terms used were: "demineralized dentine matrix", "bone grafting", "bone augmentation" and "guided tissue regeneration" in various combinations. Original studies (in vitro, animal and human) and systematic reviews were included in the literature search. The literature search initially identified 23 studies (16 animal studies and 7 clinical reports. Most studies included in this review indicate that DDM has demonstrated promising results in a variety of dental and regenerative medicine applications. Further studies are required to completely comprehend its characteristics and prospective applications. Future studies should also focus on optimizing the processing protocols for the production of DDM-based scaffolds.

The effect of fibroblast growth factor-2 on the outcomes of tooth replantation: A systematic review of animal studies.

Background/Aim: The ideal treatment of tooth avulsion is replantation. However, replanting teeth may lead to root resorption. Fibroblast growth factor-2 (FGF-2) is a cytokine that plays an important role in wound repair and tissue regeneration. Recently, FGF-2 has been studied a potential regenerative agent to prevent root resorption and ankylosis. The aim of this review is to analyze and summarize the currently available literature focusing on using FGF-2 based regenerative modalities to improve the outcomes of tooth replantation. Materials and Methods: An electronic search was conducted via PubMed/Medline, Google Scholar and ISI Web of Knowledge, using the Medical Subject Headings (MeSH) terms "Basic fibroblast growth factor," "Fibroblast growth factor-2," "tooth replantation," and "replantation" for studies published between January 2001 and June 2021. Data was extracted and quality assessment was carried using the ARRIVE guidelines. Results: Nine animal studies were included in this review. In six studies, FGF-2 had a favorable effect on the tissue regeneration around roots of replanted teeth when compared to other treatment groups. However, quality assessment of the studies revealed many sources of bias and deficiencies in the studies. Conclusions: Within the limitations of this study, it may be concluded that FGF-2 may improve the outcomes of delayed replantation of avulsed teeth. However, more long-term animal studies, with improved experimental designs, and clinical trials are required to determine the clinical potential of the growth factor in improving the outcomes of delayed tooth replantation.

Development, physicochemical characterization and in-vitro biocompatibility study of dromedary camel dentine derived hydroxyapatite for bone repair.

This study aimed to produce hydroxyapatite from the dentine portion of camel teeth using a defatting and deproteinizing procedure and characterize its physicochemical and biocompatibility properties. Biowaste such as waste camel teeth is a valuable source of hydroxyapatite, the main inorganic constituent of human bone and teeth which is frequently used as bone grafts in the biomedical field. Fourier Transform infrared (FTIR), and micro-Raman spectroscopy confirmed the functional groups as-sociated with hydroxyapatite. X-ray diffraction (XRD) studies showed camel dentine-derived hydroxyapatite (CDHA) corresponded with hydroxyapatite spectra. Scanning electron micros-copy (SEM) demonstrated the presence of dentinal tubules measuring from 1.69-2.91 µm. The inorganic phases of CDHA were primarily constituted of calcium and phosphorus, with trace levels of sodium, magnesium, potassium, and strontium, according to energy dispersive X-ray analysis (EDX) and inductively coupled plasma mass spectrometry (ICP-MS). After 28 days of incubation in simulated body fluid (SBF), the pH of the CDHA scaffold elevated to 9.2. in-vitro biocompatibility studies showed that the CDHA enabled Saos-2 cells to proliferate and express the bone marker osteonectin after 14 days of culture. For applications such as bone augmentation and filling bone gaps, CDHA offers a promising material. However, to evaluate the clinical feasibility of the CDHA, further in-vivo studies are required.

Extraction of Hydroxyapatite from Camel Bone for Bone Tissue Engineering Application.

Waste tissues such as mammalian bone are a valuable source from which to extract hydroxyapatite. Camel bone-based hydroxyapatite (CBHA) was extracted from the femur of camel bones using a defatting and deproteinization procedure. The extracted CBHA was mechanically, chemically, physically, morphologically and structurally characterized. Fourier-Transform Infra-Red (FTIR) spectra, Micro-Raman, and X-ray diffraction analysis confirmed successful extraction of hydroxyapatite. The mechanical properties of the CBHA scaffold were measured using a Universal Instron compression tester. Scanning electron microscopy showed the presence of a characteristic interconnected porous architecture with pore diameter ranging from 50-600 µm and micro-computer tomography (Micro-CT) analysis identified a mean porosity of 73.93. Thermogravimetric analysis showed that the CBHA was stable up to 1000 °C and lost only 1.435% of its weight. Inductively coupled plasma-mass spectrometry (ICP-MS) and Energy-dispersive-X-ray (EDX) analysis demonstrated the presence of significant amounts of calcium and phosphorus and trace ions of sodium, magnesium, zinc, lead and strontium. Following 21 days of incubation in simulated body fluid (SBF), the pH fluctuated between 10-10.45 and a gradual increase in weight loss was observed. In conclusion, the extracted CBHA is a promising material for future use in bone tissue regeneration applications.

The Regenerative Potential of Decellularized Dental Pulp Extracellular Matrix: A Systematic Review.

INTRODUCTION: The regeneration of dental pulp remains a challenge. Although several treatment modalities have been proposed to promote pulpal regeneration, these treatments have several drawbacks. More recently, decellularized dental pulp extracellular matrix (DP-ECM) has been proposed to regenerate dental pulp. However, to date, no systematic review has summarized the overall outcome and assessed the available literature focusing on the endodontic use of DP-ECM. The aim of this systematic review is to critically appraise the literature, summarize the overall outcomes, and provide clinical recommendations about DP-ECM. METHODOLOGY: Following the Participants Intervention Control and Outcomes (PICO) principle, a focused question was constructed before conducting a search of the literature and of electronic research databases and registers. The focused question was: 'Compared to controls, does decellularized dental pulp extracellular matrix (DP-ECM) stimulate the regeneration of dental pulp cells and tissue?' Quality assessment of the studies was carried out using Guidelines for Reporting Pre-Clinical in Vitro Studies on Dental Materials and ARRIVE guidelines. RESULTS: 12 studies were included in this review. Data from five in vitro experiments and eight in vivo experiments were extracted and the quality of the experiments was assessed. In majority of the studies, DP-ECM appeared to have stimulated pulpal regeneration. However, several sources of bias and methodological deficiencies were found during the quality assessment. CONCLUSION: Within the limitations of this review and the included studies, it may be concluded that there is insufficient evidence to deduce the overall efficacy of DP-ECM for pulpal regeneration. More research, clinical and pre-clinical, is required for more conclusive evidence.

Evaluation of Root Canal Configuration of Maxillary and Mandibular First Molar by CBCT: A Retrospective Cross-Sectional Study.

Adequate knowledge of root canal morphology along with its probable variations is imperative to acquire successful endodontic treatment. This retrospective cross-sectional study aimed to investigate the root canal configuration of maxillary and mandibular first molar using Cone-Beam Computed Tomography (CBCT) among patients in Al-Ahsa region, Saudi Arabia. A total of 377 samples were included, out of which 123 CBCT (I-CAT Vision QTM) scans with intact all first permanent molars were selected in this study and scanned in sagittal, axial, and coronal views by using BlueSkyPlan software. The number of canals in each root and their configuration according to the Vertucci classification system was evaluated. Statistical analysis was analyzed using SPSS version 21 (IBM). Chi-square test was applied to evaluate the association of root canal morphology and mandibular and maxillary first molars with respect to gender. Out of 123 CBCT scans, 59 (48.0%) were males and 64 (52.0%) were females; the mean age was 26.95 ± 10.65 years. The mesiobuccal root of bilateral maxillary first molar had Type-I (87.0%) of Vertucci classification followed by Type-IV (9.8%). Additionally, all mesiobuccal roots (100%) of the left mandibular first molar had Type-I of Vertucci's classification. A significant association has been observed between gender and a number of canals in bilateral maxillary first molars. Females showed a significantly higher prevalence of three-root canal configuration in maxillary first molars of both sides compared four canals found most commonly in males (p = 0.004). This study concluded that the majority of maxillary and mandibular permanent first molars had three roots and three canals with Type-I Vertucci's classification in patients belonging to the Al-Ahsa region of the Saudi Arabia. It was also proved that gender is significantly associated with the number of canals in a bilateral maxillary molar.

Future of Decellularized Dental Pulp Matrix in Regenerative Endodontics.

With the advancements in tissue engineering, the repair and regeneration of oral/dental tissue are becoming possible and productive. Due to periodontal diseases, the tooth loses bone support resulting in tooth loss, but bone grafting stabilizes with new bone. It is seen that due to the progression of dental caries, pulp damage happens, and the vitality of the tooth is compromised. The current theme of dental pulp regeneration through biological and synthetic scaffolds, is becoming a potential therapy for pulp revitalization.

Dental Practitioners' Knowledge, Attitude and Practices for Mouthwash Use Amidst the COVID-19 Pandemic.

INTRODUCTION: COVID-19 created a peculiar situation worldwide, thus altering the fundamental dynamics of clinical dentistry. This KAP survey was carried out to evaluate the knowledge, attitude and practices among dental practitioners regarding the use of mouthwashes and emphasize on pre-procedural utilization of mouthwashes. METHODOLOGY: A descriptive, cross-sectional study was conducted during 1st to 15th July 2020, among working dental practitioners across the globe. A questionnaire was formed on Kwiksurveys.com, it comprised of demographic details, it further investigated the level of knowledge and new precautionary measures adopted. A total number of 707 dental practitioners from eighteen different countries responded. RESULTS: Data were analyzed using SPSS version 23. A "fisher exact test" was applied to assess the difference between the mouthwashes prescribed by various countries. Knowledge section revealed a requisite understanding regarding the disease and its transmission. Only 38.9% of the participants knew that Povidone-iodine (PVP-I) mouthwashes are more efficient in reducing coronaviruses in contrast to mouthwashes made of chlorhexidine (CHX). Whereas 33.9% knew that 0.23% of PVP-I had substantial virucidal activity against SARS-COV, MERS-CoV, influenza virus and rotavirus while 31.1% recognized that oral rinses of Cetylpyridinium chloride (CPC) remained successful in the oral cavity for up to 180-300 minutes. CONCLUSION: There is an immense need to raise awareness among practitioners, regarding the viricidal activity of commercially available mouthwashes as demonstrated by numerous in-vitro studies and urge health workers to carry out more clinical trials and to get a translational step towards clinical practice.

Effect of Different Host-Related Factors on Postoperative Endodontic Pain in Necrotic Teeth Dressed with Interappointment Intracanal Medicaments: A Multicomparison Study.

OBJECTIVES: The current study aimed to assess the impact of factors such as age, gender, and the tooth type on postoperative endodontic pain in necrotic teeth with symptomatic periapical periodontitis and radiolucency dressed randomly with either calcium hydroxide or propolis paste. MATERIALS AND METHODS: The standard chemomechanical root canal preparation of 80 teeth was performed by the primary investigator. The intracanal medicaments were inserted by the secondary operator. Patients self-recorded their postoperative endodontic pain intensity with the help of visual analog scale at 4, 12, 24 (day 2), 48 (day 3), and 72 (day 4) hours. During analysis, patients (68/80) were grouped according to gender, age, and the tooth type. STATISTICAL ANALYSIS: Mann-Whitney's U test was applied for mean pain score comparison between genders and between tooth type. Kruskal-Wallis' test was applied for mean pain score comparison between the age groups. RESULTS: No significant difference (p > 0.05) in pain scores was found between the age groups and between the tooth types. Males had significantly higher pain scores as compared with females at days 2 (p = 0.035), 3 (p = 0.023), and 4 (p = 0.020). CONCLUSION: The results suggested that there was no impact of age and tooth types on postoperative endodontic pain.

Evaluation of Patient's Knowledge, Attitude, and Practice of Cross-Infection Control in Dentistry during COVID-19 Pandemic.

OBJECTIVES: The aim of this study was to evaluate the patient's knowledge, attitude, and practice of cross-infection control in dentistry during coronavirus diseases 2019 (COVID-19). MATERIALS AND METHODS: This cross-sectional observational study was conducted at Altamash Institute of Dental Medicine, Karachi from June 2020 to August 2020. A total of 775 patients participated to fill questionnaire. After scrutiny, 25 questionnaire forms were excluded due to incomplete information. Questionnaire was divided in to four sections. First section obtained patients sociodemographic information, while knowledge of patients regarding cross-infection control during COVID-19 pandemic was evaluated in second section. Similarly, the purpose of third section was to assess attitude and fourth section was designed to evaluate practice. Likert's 3-point scale was used for registration of participant's response. The reliability of questionnaire was assessed through Crohnbach's α (α = 0.74). Statistical analysis was performed after entering data in to SPSS version 25. Independent t-test was used to evaluate the difference in patients' knowledge, attitude, and practice. A p-value ≤ 0.05 was considered as statistically significant. RESULTS: Majority of the participants agreed that COVID-19 is a highly contagious disease (631, 97%) and daily screening of staff, dental assistants, dentists, and patients is necessary (568, 75.7%) along with proper sterilization of instruments and disinfection of dental operatory (650, 86.66%). A large number of participant also agreed that proper disposal of waste is utmost important for cross-infection control (601, 80.24%) and patient's waiting area should also be marked with social distancing sign (620, 82.66%). However, when asked about the common route of COVID-19 transmission in dentistry, 341 (45.5%) participants disagreed that it is not through aerosol (water droplets) generated during dental procedures. CONCLUSIONS: Dental health professionals should take additional measures to educate dental patients on mechanism of potential spread of COVID-19 through the aerosols and droplets generated during dental procedures. They should also encourage the dental patients to be vigilant and question the cross-infection control measures practiced by the dentist to whom they go for dental treatment, and to decrease their chances of acquiring an infection during their visit to the dental office.

Salivary IgA as a Useful Biomarker for Dental Caries in Down's Syndrome Patients: A Systematic Review and Meta-analysis.

The objective of this systematic review and meta-analysis is to critically analyze and summarize studies reporting association of salivary immunoglobulin A (IgA) levels as a biomarker for dental caries in Down syndrome (DS) patients. Using the keywords salivary [All Fields] AND IgA [All Fields] AND ("down syndrome" [MeSH Terms] OR ("down"[All Fields] AND "syndrome" [All Fields]) OR "down syndrome" [All Fields]), an electronic search was conducted via PubMed and Scopus databases by two authors, H. H. and Z. K. independently. Retrieved studies were screened against the predefined exclusion and inclusion criteria. To estimate the risk of bias, quality assessment of included studies was carried using the Newcastle-Ottawa quality assessment scale for observational studies. Primary search resulted in 10 articles from PubMed and 13 articles from Scopus. Ten studies fulfilled the defined selection criteria and evaluated the salivary IgA (sIgA) level in DS patients with dental caries. Five articles were further analyzed in a quantitative synthesis presented in the meta-analysis. Due to a modified lifestyle and compromised oral hygiene in DS patients, understandably, it is still postulated in the literature that the presence of sIgA can have a protective effect on the occurrence of dental caries as compared with healthy counterparts. As indicated by the present meta-analysis, no conclusions can be drawn as to definitively label sIgA as a biomarker for dental caries. Further, well-designed longitudinal clinical studies and translational research are therefore required before the benchmarking of sIgA as a useful biomarker for dental caries in DS patients with preferable molecular insights.

Periostin: Immunomodulatory Effects on Oral Diseases.

Periostin is a microcellular adapter protein. It plays a wide range of essential roles during the development and in immunomodulation. Periostin is a prominent contributor during the process of angiogenesis, tumorigenesis, and cardiac repair. It is expressed in periodontal ligaments, tendons, skin, adipose tissues, muscle, and bone. This is a protein-based biomolecule that has the diagnostic and monitoring capability and can potentially be used as a biomarker to detect physiological and pathological conditions. The aim of the present review was to explore the periostin morphology and associated structural features. Additionally, periostin's immunomodulatory effects and associated biomarkers in context of oral diseases have been discussed.

COVID-19 Pandemic and Role of Human Saliva as a Testing Biofluid in Point-of-Care Technology.

Novel coronavirus disease 2019 (COVID-19) outbreak has termed as a controllable pandemic, and the entire world has come to a standstill trying to mitigate the disease with health systems. Health care providers, around the globe, are fighting day and night. Currently, rapid testing is taking place with the help of nasopharyngeal, oropharyngeal swab, bronchoalveolar lavage, sputum, urine, and blood. All these approaches are invasive or embarrassing to the infected person. It is observed that salivary glands are hosting severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) because of angiotensin-converting enzyme 2 and the detection of high viral loads in the saliva and is playing a crucial role in virus transmission, especially from individuals showing absolutely no symptoms. Saliva is proving to be a promising noninvasive sample specimen for the diagnosis of COVID-19, thus helping to monitor the infection and prevent it from further spreading by prompt isolation.

Aspects of Clinical Malpractice in Endodontics.

The clinical dentistry and endodontic procedures involve very technique-sensitive procedures, therefore exposing the operator to risks of causes not only damage to patients but also leads to malpractice. Among various disciplines of dentistry, endodontics-related cases witness the most frequently filed malpractice claims. This is due to the fact that the endodontic treatment procedures involve operative and surgical procedures, using a variety of medicaments and techniques. The endodontic procedural errors can be preoperative errors (such as incorrect diagnosis and misinterpretation), intraoperative errors including root canal and pulp chamber perforations, ledge formation leading to apical transportation or zipping, hypochlorite accidents, and fracture of instruments. More critically, failure to use rubber dam may result in inhalation or ingestion of endodontic instruments. Under such circumstances, the endodontist may have to face legal consequences. Due to the increased healthcare load and patients' awareness, it is important to know the legal ramifications of adverse effects, failed restorations, or other complications, to avoid any legal ramifications of endodontic procedures and associated techniques. Therefore, precautions must be taken to prevent any postsurgical complications, patient complaints, and/or failures. For this purpose, the operator must consider ethical principles and adhere strictly to the standards of healthcare while performing the diagnosis and treatment. A referral toward a specialist or consultant endodontist is always an appreciable option and should be considered in the best interest of the patient. The aim of the article is to highlight various aspects of malpractice in clinical endodontics, and associated materials and challenges. In addition, commonly occurring operating errors during endodontic treatment, possible consequences, precautions, and management have been discussed.

Fracture Resistance of Roots Restored with Four Different Fiber-Reinforced Composite Posts.

OBJECTIVE: The aim of this study was to compare the resistance to vertical root fracture of root-filled teeth restored with four different fiber-reinforced composite (FRC) post systems and two types of dual-cured resin luting agents. MATERIALS AND METHODS: Ninety extracted human maxillary central incisors were selected and decoronated to obtain a standardized root length of 14 mm. After root canal obturation, post spaces were prepared to a depth of 10 mm with a No. 3 post drill. The specimens (n = 80) were divided into two groups (n = 40) according to the resin luting agents used: group 1, Variolink II + ExciTE DSC; group 2, RelyX Unicem. These groups were subdivided into four subgroups (n = 10) and restored with one of the following post systems: (a) DT Light, (b) DT Light SL, (c) FRC Postec and (d) Everstick, while the remaining 10 teeth served as controls. The roots were subjected to axial compressive loading using a 2.2-mm-diameter metal sphere in a universal testing machine (0.5 mm/min). A factorial experiment with a single control group (analysis of variance) was used to test the resistance of the specimens. RESULTS: Groups 2a (DT Light + RelyX Unicem; 398.5 N) and 1b (DT Light SL + Variolink II + ExciTE DSC; 431.1 N) had significantly higher resistance to fracture than the control group (334.1 N; p < 0.05). DT Light SL and FRC Postec Plus were more resistant to fracture when Variolink II was used as the luting cement. DT Light and Everstick had higher fracture resistance when they were luted with RelyX Unicem (p < 0.05). CONCLUSION: The results of this study indicate that the use of quartz fiber posts (DT Light and DT Light SL) with an adhesive luting cement in root-filled teeth may reinforce the root to some extent.

Comparison of cytotoxicity of various concentrations origanum extract solution with 2% chlorhexidine gluconate and 5.25% sodium hypochlorite.

OBJECTIVE: The purpose of this in vitro study was to compare the cytotoxicity of 0.5-4.5 origanum extract solution (OES), 2% chlorhexidine gluconate (CHX) and 5.25% sodium hypochlorite (NaOCl) with WST-1 test on human periodontal ligament (hPDL) fibroblasts. MATERIALS AND METHODS: About 0.5-4.5% OES, 2% CHX and 5.25% NaOCl solutions cytotoxicity was evaluated with cell culture test using PDL fibroblasts. Viability of hPDL cells was evaluated with WST-1 (Cell Proliferation Reagent WST-1 Roche) test at 1, 24 and 72(nd) h. hPDL cells were plated at 20 × 10(3) cells per well in 96-well plates. Absorbance values were read in optical density 480 nm by ELISA plate reader spectrophotometer. The statistical differences between various groups were evaluated using one-way ANOVA, post-hoc Duncan's Multiple Range test using SAS software. Statistically, a significant difference was considered at P < 0.001. RESULTS: According to the 1-h cytotoxicity results, 0.5% OES showed the least cytotoxic effect in test groups. There were not found any statistical significance between 1% OES and 2% CHX. About 5.25% NaOCl showed more cytotoxic effect than 1% OES and 2% CHX. In 24 and 72 h, different concentrations of OES, 5.25% NaOCl, 2% CHX solutions showed similar cytotoxic effect. CONCLUSIONS: Based on these results, 1% OES and 2% CHX showed similar results and less cytotoxic effect than 5.25% NaOCl. It could be considered as a favorable solution concentration when OES was used as root canal irrigation solution.

Antibacterial and smear layer removal capability of oregano extract solution.

OBJECTIVE: The aim of this in vitro study was to evaluate the antimicrobial effect of oregano extract solution (OES) against Enterococcus faecalis within root canals and dentin tubules, and its effect on smear layer. MATERIALS AND METHODS: A total of 180 human maxillary central incisors was selected. After removal of coronal part of the teeth, root canals were prepared using ProTaper rotary files (Dentsply, Tulsa Endodontics, OK, USA) to #F3 with the crown-down manner. The roots were randomly assigned to 15 groups (n = 12 for each). In the first seven groups, the antimicrobial effects of the test groups were evaluated. Suspensions of E. faecalis cultures were adjusted to 1.0 McFarland (1 × 10(8) colony-forming unit [CFU]/ml), and sterilized teeth were placed in Eppendorf tubes and kept at 37°C for 4 weeks. Samples were then taken from the root canals before irrigation using three sterile paper points. Dentin samples were taken from root canals with ProTaper #F4 and #F5 series rotary instruments after irrigation. The aliquots of samples were placed into the brain heart infusion and incubated at 37°C for 48 h and then the CFUs were counted. In the other eight groups, the efficacy of the irrigation solutions on removing the smear layer was evaluated using scanning electron microscope (Leo 440, Oxford Microscopy Ltd., Cambridge, England) analysis. Statistical evaluation of the microbiological data was performed using the Kruskall-Wallis and Mann-Witney U-test (P < 0.05). RESULTS: There was a statistically difference between the groups (P < 0.05). Chlorhexidine gluconate (CHX), 5% and 2% OES wasn't found to be statistically significant regarding their antibacterial activities against E. faecalis (P > 0.05). 1% OES and NaOCl showed similar antimicrobial effect (P > 0.05), and 1% OES and NaOCl were better than ethylenediaminetetraacetic acid (EDTA) and saline (P < 0.05) but not as successful as CHX. According to the results obtained from dentin, CHX is the most effective solution within dentinal tubules. Different concentrations of OES were not achieved smear layer removal alone but OES in conjunction with 17% EDTA was the final irrigating solution achieved the smear layer removal without dentin erosion. CONCLUSIONS: Within the limitations of this study, OES appears to be a possible alternative to NaOCl as a root canal irrigant on the eradication of E. faecalis and removal of smear layer.

Microleakage under orthodontic brackets bonded with different adhesive systems.

OBJECTIVE: This in vitro study aimed to compare the microleakage of orthodontic brackets between enamel-adhesive and adhesive-bracket interfaces at the occlusal and gingival margins bonded with different adhesive systems. MATERIALS AND METHODS: A total of 144 human maxillary premolar teeth extracted for orthodontic reasons was randomly divided into four groups. Each group was then further divided into three sub-groups. Three total-etching bonding systems (Transbond XT, Greengloo and Kurasper F), three one-step self-etching bonding systems (Transbond Plus SEP, Bond Force and Clearfil S3), three two-step self-etching bonding systems (Clearfil SE Bond, Clearfil Protectbond and Clearfil Liner Bond), and three self-adhesive resin cements (Maxcem Elite, Relyx U 100 and Clearfil SA Cement) were used to bond the brackets to the teeth. After bonding, all teeth were sealed with nail varnish and stained with 0.5% basic fuchsine for 24 h. All samples were sectioned and examined under a stereomicroscope to score for microleakage at the adhesive-enamel and adhesive-bracket interfaces from both occlusal and gingival margins. STATISTICAL ANALYSIS USED: Statistical analyses were performed with Kruskal-Wallis and Wilcoxon signed-rank tests. RESULTS: The results indicate no statistically significant differences between the microleakage scores of the adhesives; microleakage was detected in all groups. Comparison of the average values of the microleakage scores in the enamel-adhesive and adhesive-bracket interfaces indicated statistically significant differences (P < 0.05). The amount of the microleakage was higher at the enamel-adhesive interface than at the bracket-adhesive interface. CONCLUSIONS: All of the brackets exhibited some amount of microleakage. This result means that microleakage does not depend on the type of adhesive used.

In vitro evaluation of shear bond strengths of colour change adhesives.

The aims of this study were to test whether the shear bond strengths (SBS) of three commercially available colour change adhesives (CCAs), Transbond Plus Color Change Adhesive, Grengloo, and Blugloo, are different and to compare their bond strengths with a traditional light cure adhesive, Light Bond. Forty-eight human permanent premolar teeth extracted for orthodontic reasons and without any caries or visible defects were used in this study. The brackets were bonded with Light Bond (group I), Grengloo (group II), Blugloo (group III), and Transbond Plus CCA (group IV). After bonding, the SBS of the brackets were tested with a Universal testing machine. Analysis of variance indicated a significant difference between groups I and IV (P < 0.001). No significant difference was found between groups II, III, and IV (P > 0.05). Adhesive remnant index (ARI) scores for all groups were not significantly different (P > 0.05). Significant difference existed between the SBS of Transbond Plus CCA and Light Bond. Although Transbond Plus CCA yielded the lowest SBS values, no statistically significant difference was found between bond strength values of the three commercially available CCAs. All three CCAs can be safely used in orthodontic practice since they yielded acceptable bond strengths. A higher incidence of ARI scores 4 and 5 revealed that bond failures in all test groups were mainly at the adhesive interface.

Effects of fluorosis and self etching primers on shear bond strengths of orthodontic brackets.

OBJECTIVES: To evaluate the effects fluorosis and self etching primers (SEP) on shear bond strengths (SBS) of orthodontic brackets. METHODS: A total of 48 (24 fluorosed and 24 non-fluorosed) non-carious freshly extracted human permanent premolar teeth were used in this study. Fluorosed teeth were selected according to the modified Thylstrup and Fejerskov index (TFI), which is based on the clinical changes in fluorosed teeth. Fluorosed and non-fluorosed teeth were randomly assigned to 4 groups of 12 each. In groups I (non-fluorosed teeth) and II (fluorosed teeth), standard etching protocol was used and brackets were bonded with Light Bond. In groups III (non-fluorosed teeth) and IV (fluorosed teeth), Transbond Plus SEP was used and brackets were bonded with Transbond XT Light Cure Adhesive. All specimens were cured with a halogen light. After bonding, SBS of the brackets were tested with Universal testing machine. After debonding, all teeth and brackets in the test groups were examined under 10x magnifications. Any adhesive remained after debonding was assessed and scored according to the modified Adhesive Remnant Index (ARI). RESULTS: ANOVA indicated a significant difference between groups (P<.001). SBS in group II (Light Bond+Fluorosis) were significantly lower than other groups. ARI scores of the groups were also significantly different (P<.001). There was a greater frequency of ARI scores of 1,2 and 3 in group II (Light Bond+Fluorosis). CONCLUSIONS: When standard etching protocol was used enamel fluorosis significantly decreased the bond strength of orthodontic brackets. Satisfactory bond strengths were obtained when SEP was used for bonding brackets to the fluorosed teeth.