To compare the depth of cure of nanofiller containing with conventional resin composites.

Five nanofilled and nanohybrid composites were investigated and compared with a microfilled and a microhybrid reference, using the ISO 4049 scraping test, Knoop hardness (KHN) and DC profiling. Specimens from all materials (shade A3) were activated with the same LED light source for 20s. KHN (0.25N/15s) of three specimens each, produced in split molds was measured after 24 hours dark storage on sections perpendicular to the irradiated surface at 250 µm distance along the center line and two parallel lines, 0.5 mm apart, to a depth of 3 mm. Mean KHNs of the three neighboring indentations at each level were calculated. Degree of conversion (DC) was determined on specimens as mentioned above using micro-Raman spectroscopy at 125 µm distance with three measurements at each depth level.

The depth of cure of all materials was >2 mm when determined according to the ISO test. KHN and DC data followed second order polynomial regression lines (r² > 0.70; p < 0.001). At 2 mm depth, the KHN of six resin composites was ≤80% of the top KHN whereas the DC of all materials was ≥86% of the maximum DC at the irradiated surface.

The ISO scraping test overemphasizes the attainable depth of cure, when compared with 80% of top KHN as arbitrarily defined curing depth. KHNs reflect the crosslink density of the polymer, whereas DC additionally includes double bond conversions not contributing to enhancement of mechanical characteristics.

Kanehira M, Araki Y, Finger WJ, Wada T, Utterodt A, Komatsu M. Curing Depth of Light-activated Nanofiller containing Resin Composites. World J Dent 2012;3(2): 119-125.

The purpose of the study was to analyze the frequency and distribution of gingival lesions in MR Ambedkar Dental College, Bengaluru.

The material included the biopsies of all localized reactive hyperplastic lesions (LRHL) of the gingiva stored in the department's database (1995-2011). The lesions were analyzed according to their location and the patient's age and gender. The findings were compared with other published studies on reactive lesions.

A total of 260 reactive lesion biopsies were accessed. focal fibrous hyperplasia (FFH) was the most common (38.5%), followed by pyogenic granuloma (PG) (34.6%), peripheral ossifying fibroma (POF) (17.7%) and peripheral giant cell granuloma (PGCG) (9.2%). The mean age of the patients was 33 years, with a range varying from 9 to 80 years. The LRHL occurred more commonly in females except focal fibrous hyperplasia, which showed male predilection. PG and POF were more common in the maxilla and FFH as well as PGCG were more common in the mandible.

This study indicates some differences in age and gender distribution as well as in location between the different lesions. The results of this study differ from those of other studies and the data presented here can be used as a guide for further multicenter studies.

Ramu S, Rodrigues C. Reactive Hyperplastic Lesions of the Gingiva: A Retrospective Study of 260 Cases. World J Dent 2012;3(2):126-130.

Six fiber-reinforced groups (n = 10) were made with three different lengths (10, 15, 20 mm) with or without glass fiber in split mold. The specimens were early cured and then post-cured with a labolite unit, then specimens were subjected to three-point flexural test by a universal testing machine. Data were analyzed with ANOVA and LSD post-hoc test (p < 0.05).

Maximum fracture load of specimens increased with decreasing lengths (p < 0.001) and fiber-containing group showed significantly higher fracture load than fiberless groups (p < 0.001).

It was concluded that by increasing the span length, the maximum fracture load values (N) decreased incorporation of fiber results in higher fracture strength values.

Omid T, Venus MM, Farahnaz S, Asghar AA. Effect of Glass Fiber Length on Flexural Strength of Fiber-reinforced Composite Resin. World J Dent 2012;3(2):131-135.

This study was conducted on 125 patients who attended the orthodontic department from December 2008 to June 2010. Information regarding age, sex, type of malocclusion, dentofacial patterns and dentofacial characteristics was obtained from patients records. Orthodontic treatment need was assessed using DHC component of IOTN.

The results of the study showed that the patients age ranged from 10 to 33 years with mean age of 16 years 9 months (+ 3.92). There were 91 (72.8%) females and 34 (28.2%) males. Chief complaints of majority of patients were ‘upper front teeth forward’ and ‘irregular teeth’. The commonest type of malocclusion was Angle's class II which was seen in 60 (48%) of patients. There was an increased overjet in 81% of subjects. Statistically significant association was found between skeletal and Angle's classes (p < 0.01). Assessment of need for orthodontic treatment using the DHC component of IOTN showed that 59 (47.2%) were in great need of orthodontic treatment and 53 (42.4%) had definite need of treatment.

The results give a detailed pattern of malocclusion in orthodontic patients and may provide a baseline data for research and planning orthodontic services.

Nanjannawar L, Agrawal JA, Agrawal M. Pattern of Malocclusion and Treatment Need in Orthodontic Patients: An Institution-based Study. World J Dent 2012;3(2):136-140.

Tonetto MR, de Oliveira Junior OB, de Campos EA, Saad JRC, Dantas AAR, de Souza Rastelli AN, de Toledo Porto Neto S, de Andrade MF. Fluorescence Level of Composites assessed by Computer Processing of Digital Images: ScanWhite^©. World J Dent 2012;3(2):141-144.

This in vitro study aimed to evaluate the effect of different monomer systems on microleakage in class II composite open sandwich restorations with and without a separating agent placed between the nanofilled resin modified glass ionomer and the resin.

Class II cavity preparations were prepared in maxillary premolars (n = 240) and the cervical limit of the proximal box was below the cementoenamel junction. Group 1 was restored with silorane-based composite and group II was restored with methacrylate-based composite. All specimens were subjected to thermocycling and examined for microleakage after in 50% silver nitrate solution. The recorded results of dye penetration were statistically analyzed using Chisquare test.

Methacrylate-based composite (Filtek Z 350, 3M, St Paul, MN, USA) exhibited the highest dye penetration and silorane-based composite (Filtek P90 Low Shrink Posterior Restorative, 3M, St Paul, MN, USA) showed the lowest dye penetration among the restorative materials. However, specimens with separating agent showed almost no leakage between the RMGIC and tooth interface.

Forces of polymerization shrinkage are stronger than the bond between glass ionomer cement and tooth interface and the use of silorane technology in open sandwich restoration will decrease microleakage and improve clinical performance.

Hegde MN, Hegde N, Hegde ND. Microleakage of Silorane-based Resin Composite in Comparison with Methacrylate-based Composite in Class II Open Sandwich Restorations: An in vitro Study. World J Dent 2012;3(2):145-149.

This in vitro study evaluated the shear bond strength of a chemical resin cement to five adhesive systems in bovine dentin.

One hundred and three bovine teeth were divided into five experimental groups (n = 19) and two control groups (n = 4). A flat dentin surface was exposed on each tooth after wet grinding the buccal enamel, in order to apply the adhesive systems (Adper Single Bond, Adper Scotchbond Multi-Purpose, Multi Bond Uno plus Duo, One Step, Prompt L-Pop) to 95 teeth, according to manufacture's instructions. Four teeth were etched with phosphoric acid (negative control) and four teeth were no etched with phosphoric acid (positive control). Light-cured composite blocks were sandblasted before the cementation with C&B Cement (Bisco) over the treated dentin. The specimens were stored in distilled water at 37°C and submitted to the shear bond strength test after 7 days.

ANOVA and Tukey tests (p = 0.05) demonstrated that Adper Single Bond (7.47 ± 4.37), Adper Scotchbond Multi-Purpose (6.68 ± 5.11) and One Step (7.30 ± 4.29) presented the highest bond strength values. Prompt L-Pop (0.05 ± 0.17) and Multi Bond Uno plus Duo (0.72 ± 1.41) presented the lowest significant bond strength values.

The shear bond strength of composite resin cylinders cemented with chemically activated resin cement depends on the adhesive system used.

Fourth and fifth generation light polymerized bonding systems are indicated when self-polymerizing cements are used.

Kubo CH, Caneppele TMF, da Silva EG, Huhtala MFRL, Torres CRG, Pagani C, Gomes APM. Shear Bond Strength of a Chemical Resin Cement to Five Adhesive Systems in Bovine Dentin. World J Dent 2012;3(2):150-155.

Parekh B, Sathe S, Hegde V. Analysis of the Effect of Dental Chair Light on the Knoop Hardness of Composite Resin While Light Curing with QTH and LED Light Units. World J Dent 2012;3(2):156-160.

This study aimed to evaluate the suitability of one specific silorane-based composite for the application as a repair material for different substrates.

Truncated cones of composites fabricated and thermocycled for 6000 cycles to serve as a substrate were made of two commercially available dimethacrylate-based composites (DBC) (Filtek Supreme and Clearfil APX) and one silorane-based composite (SBC) (Filtek P90). The surface of the specimens was treated with air-abraded using Al₂O₃-particles of 50 µm size. A Teflon device was used to fabricate inverted truncated cones of repair composite over the surface-treated top of each original truncated cone. DBC and SBC were used as repair materials and bonded to the specimens using either a dimethacrylate-based (single bond 2) or a phosphate-methacrylate-based (adhesive belongs to the silorane) adhesives. The specimens were stored in distilled water at 37°C for 7 days and stressed to failure under tension. The data were analyzed with one-way ANOVA and Tukey tests at 5%.

Bonding DBC as a repair material to a DBC substrate using the dimethacrylate-based adhesive produced the highest bond strength. Bonding DBC as repair material using the phosphate-methacrylate-based adhesive or SBC as repair material using the dimethacrylate-based adhesive produced lower bond strength, regardless the brand and of the chemical formulation of the aged substrate.

In order to obtain high bond strength, there is need to match adhesive and repair material, regardless the brand and of the chemical formulation of the substrate.

Barcellos DC, Pleffken PR, Pucci CR, Pagani C, Gonçalves SEP, Torres CRG. Effectiveness of Silorane-based Composite as a Repair Filling for Dimethacrylate- or Silorane-based Composite Restorations. World J Dent 2012;3(2):161-65.

The system Resilon/Real Seal did not achieve better results in terms of sealing ability in the apical third when compared to the conventional gutta-percha/AH plus sealing system.

Zogheib C, Naaman A, Medioni E. Evaluation of Apical Filling after Warm Vertical Compaction using Two Different Endodontic Materials: Resilon^® and Gutta-Percha. World J Dent 2012;3(2):166-170.

The aim of this study was to evaluate mechanical property hardness and surface roughness (Ra) of different polymerization acrylic resins used for denture bases.

A total of 30 specimens were prepared and divided in two groups. A total of 15 samples were processed by the compression molding technique using Meliodent (heatcured). Another 15 samples were processed with cold-cured resin Futura Gen via the injection molding technique.

Hardness testing was conducted using a Vickers hardness tester. The Ra test was performed by a profilometer. Data were analyzed using the independent sample t-test and differences were statistically significant at the 0.05 level.

The Vickers hardness numbers (VHN) were 20.8 ± 2.39 for Meliodent and 21.18 ± 1.42 for FuturaGen, which was not significantly different (p > 0.05). The Ra of Meliodent was 0.92 ± 0.23 µm and for FuturaGen it was 0.84 ± 0.37 µm. There were no significant changes in roughness.

The hardness and Ra of Meliodent and FuturaGen were not significantly different. Therefore, we recommend the use of FuturaGen for manufacturing denture base materials.

Bahrani F, Safari A, Vojdani M, Karampoor G. Comparison of Hardness and Surface Roughness of Two Denture bases Polymerized by Different Methods. World J Dent 2012;3(2):171-175.

The objective of this study was to evaluate the influence of the Grander technology on the shear bond strength of total-etch adhesive system Single Bond 2 to dentin.

Forty bovine incisors were used. They were sectioned and the buccal surfaces worn down with abrasive paper. Acid etching was performed, and the specimens were divided into two groups (n = 20): Group G1—Single Bond 2 adhesive system (3M ESPE) under normal conditions; group G2—Single Bond 2 adhesive system modified by physical contact for 48 hours with the flexible unit Grander system. The resin composite was inserted with the aid of a metallic matrix over the prepared area. After the mechanical shear test, data were submitted to the statistical t-test (5%). The t-test showed that the results for G1 and G2 were similar (p > 0.05). The mean values (± SD) were: G1—6.66 (± 2.40); G2—5.26 (± 2.15).

Grander technology did not influence the initial shear bond strength of the Single Bond 2 adhesive system to dentin.

Duarte DG, de Paiva Gonçalves SE, Barcellos DC, Huhtala MFRL, Bresciani E, Pucci CR. Evaluation of Shear Bond Strength of a Grander-Modified Adhesive System to Bovine Dentin. World J Dent 2012;3(2):176-179.

This study evaluated the flow, pH and calcium release of MTA Fillapex (G1) or Fillapex plus 10% in weight of calcium hydroxide powder (G2), compared to AH Plus (G3) and Sealapex (G4).

The flow test was performed according to ISO 6876:2001 requirements. The sealers were placed into plastic tubes and immersed in deionized water. After 24 hours, 7, 14 and 28 days, the water of each tube was removed and tested to evaluate the pH values and the level of released calcium. Calcium release values were analyzed statistically by Kruskal Wallis and Dunn tests and pH values analyzed by ANOVA and Tukey tests (α = 5%).

G1 presented higher flow among all sealers. The addition of 10% calcium hydroxide into MTA Fillapex reduced the flow (p < 0.05) but, in a level, that is lower than the one recommended for ISO norms. G2 and G4 presented pH values and calcium release higher than G3 (p < 0.05) in all periods. G1 presented pH value higher than G3 (p < 0.05), except in 7 days period (p > 0.05). G4 presented higher pH values than G1 and G2, but the calcium release was similar for all periods (p > 0.05). G3 presented lower calcium release among all groups (p < 0.05).

The addition of 10% calcium hydroxide in MTA Fillapex caused reduction in flow and no negative interference in pH and/or calcium release. However, the obtained flow is different from ISO requirements.

MTA Fillapex presents levels of flow above the ISO norms. The addition of calcium hydroxide is a suggestion for solving this problem, but the impact of these procedures should be carefully evaluated.

Keine KC, Guiotti FA, Leonardo RT, Kuga MC, Duarte MAH, de Campos EA, de Andrade MF. Influence of the Addition of Calcium Hydroxide Powder on Some Physical and Chemical Properties of the Sealer MTA Fillapex. World J Dent 2012;3(2):180-183.

To investigate the effect of tooth brushing wear with and without calcium carbonate slurry on four commercial resin composites based on different filler concepts.

One nanofiller composite MI FIL (MFI, GC), one conventional hybrid type Venus (VEN) and two nanohybrid composites Venus Diamond (VED) and Venus Pearl (VEP) all from Heraeus Kulzer were examined. Forty beam-shaped specimens (12 × 3 × 3 mm) from each product were prepared and subdivided in two equal groups for pregrinding on SiC paper #600 and #4000 respectively. Ten specimens of each pre-ground group were subjected to toothbrush abrasion with calcium carbonate slurry, and 10 to toothbrushing with water only. The samples were submitted to five subsequent runs of 10,000 brushing strokes. Depth of wear and surface roughness (Ra) were measured with a profilometer after each 10 k strokes. Specimens after 50 k strokes were assessed by SEM. Additionally, the KHN (0.25 N/15 s) and the degree of conversion (DC) were determined. Data analysis was done by linear regression and ANOVA followed by Tukey's post-hoc test (p ≤ 0.05).

Toothbrushing with abrasive slurry produced significantly different wear depths: VEN > MIF > VEP > VED. Linear relationships between depth of wear and number of cycles (r² ≥ 0.94) were established for each material. Pregrinding with SiC #4000 resulted in less wear than pregrinding with #600. Ra figures were much higher for VED than for the other materials tested. MIF and VEN were uniformly abraded, whereas the largest glass fillers in VED protruded from the surroundings and the prepolymer particles in VEP were deeper abraded than the bulk of the material. Toothbrushing with water only revealed not measurable wear. Roughness Ra was practically unchanged when compared with the preground samples before challenging with toothbrushes. Ranking by KHN was: MIF < VEN, VEP < VED, by DC: MIF < VEN < VEP < VED.

Filler concepts and monomer compositions affect wear and roughness of resin composites when tooth brushed with abrasive slurry. Toothbrushing without abrasive medium produced neither wear nor roughness. Careful polishing of resin composite restorations is an important determinant of wear and surface roughness.

Suzuki T, Kyoizumi H, Araki Y, Finger WJ, Kanehira M. Toothbrush Abrasion of Resin Composites with Different Filler Concepts. World J Dent 2012;3(2):184-193.

Divyashree R, Abhilash PR. Smile Designing with Ceramic Veneers and Crowns. World J Dent 2012;3(2):194-198.

Farooq I, Imran Z, Farooq U, Leghari A, Ali H. Bioactive Glass: A Material for the Future. World J Dent 2012;3(2):199-201.

Rao RS, Premalatha BR, Mysorekar V, Juneja S. Immunofluorescence in Oral Pathology-Part III: Pathology and Immunofluorescent Patterns in Intraepithelial Immunobullous Disorders. World J Dent 2012;3(2):202-206.

Pickett FA. Management of Oral Pain. World J Dent 2012;3(2):207-212.

The aim of this review is to summarize and discuss the available information concerning the connection between the tooth and implant in a fixed partial denture.

Although implant-supported prosthesis (ISP) has substantial biological and biomechanical advantages, due to the extensive use of implant in partially edentulous patients, encounter to cases of obligatory connection between the tooth and implant is not rare. However, because of their differences, especially in support mechanism, long-term prognosis of this treatment method is a special debate in dental literature.

The literature published over the past 25 years was searched through PubMed, Medline, Google and indexed journals (search terms: tooth implant connection, tooth implant-supported fixed partial denture, tooth implant splinting, implant and tooth). The most valuable and relevant articles were selected and analyzed.

The existing studies reveal that there are certain conditions in which this method is applicable. The main advantage of the method based on literature reviewed is reducing the need to the removable prosthesis in patients that otherwise require it. The disadvantages of this connection, mainly due to different movement range of components under loading, reportedly will be minimized if some guidelines are followed.

According to available studies, this literature review supports tooth-implant connection technique where indicated, with complete attention to prudent guidelines. Further researches preferably concentrating on new methods and also long-term longitudinal studies are certainly needed before this approach can be widely used.

Ghodsi S, Rasaeipour S. Tooth-implant Connection: A Literature Review. World J Dent 2012;3(2):213-219.