Minimal Gap Size and Dentin Wall Lesion Development Next to Resin Composite in a Microcosm Biofilm Model

2017 ◽  
Vol 51 (5) ◽  
pp. 475-481 ◽  
Author(s):  
Tamires T. Maske ◽  
Nicolien K. Kuper ◽  
Maximiliano S. Cenci ◽  
Marie-Charlotte D.N.J.M. Huysmans

This in vitro study investigated the development of dentin wall lesions next to resin composite containing very small gap sizes using an in vitro biofilm model, and evaluated whether a relevant threshold for the gap size could be established. Microcosm biofilms were grown for 14 days within small interfacial gaps between dentin-resin composite discs under intermittent cariogenic challenge. The factor under study was gap size: samples were either restored with composite resin without adhesive procedure (no intentional gap; no bonding [NB] group) or with intentional gaps of 30, 60, or 90 µm, or with complete adhesive procedure (no gap; bonding [B] group). Secondary caries wall lesion progression was measured in lesion depth (LD) and mineral loss (ML) using transversal wavelength independent microradiography at 3 locations: outer surface lesion and wall lesions at 200 and 500 µm distance from gap entrance. Results from linear regression analysis showed that the presence of an intentional gap (30, 60, and 90 µm) affected the secondary caries progression at 200 µm from the gap entrance (p ≤ 0.013). The NB group did not show significant wall lesion development (ML and LD, p ≥ 0.529). At 500 µm distance almost no wall caries development was observed. In conclusion, dentin wall lesions developed in minimal gap sizes, and the threshold for secondary wall lesion development was a gap of around 30 µm in this microcosm biofilm model.

2018 ◽  
Vol 53 (1) ◽  
pp. 107-117
Author(s):  
Tamires T. Maske ◽  
Nicolien K. Kuper ◽  
Maximiliano S. Cenci ◽  
Marie-Charlotte D.N.J.M. Huysmans

This study investigated the role of a matrix metalloproteinase (MMP) inhibitor (CHX 2%) in the development of secondary caries wall lesions in different interface conditions with small (run 1) and wider gaps (run 2). Dentin discs were restored and pretreated with or without CHX 2%. In run 1, interfaces were made with gaps of 30, 60, or 90 µm. Interfaces with composite placed directly onto the dentin were either bonded (Adper Single Bond 2) or not bonded. In run 2, interfaces were made with gaps of 100 µm, with or without adhesive on the composite side (CLEARFIL SE Bond). Interfaces were either bonded or not bonded, as in run 1. Microcosm biofilms were grown on dentin-composite samples for 14 days. Caries lesion outcomes were analyzed by transversal wavelength-independent microradiography at 3 locations: the outer surface, and the interface wall at a distance of 200 and 500 µm from the gap entrance. Linear regression analyses showed that pretreatment with MMP inhibitor did not influence progression of the wall lesion at any location (p ≥ 0.218). Interfaces with intentional gaps showed positive and significant effect on the wall lesion progression at 200 µm from the gap entrance (p ≤ 0.005). A small trend of increase in wall lesion development was observed at the 200-µm location when bonding was present on the composite side. In conclusion, the dentin pretreatment with CHX 2% was not able to slow down the development of secondary caries wall lesions in small and wide gaps in this biofilm model.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Morakot Piemjai ◽  
Pareewan Chantarawej ◽  
Nobuo Nakabayashi

Purpose. Secondary caries originate from a leakage pathway where oral acids can penetrate faster and demineralize the tooth substrate deeper which can be visualized by dye penetration. The ability to prevent secondary caries by contemporary adhesive systems was evaluated in this study. Dye penetration distance through leakage and into the tooth substrate adjacent to Class V restorations after artificial caries exposure was compared. Materials and Methods. Previously frozen extracted human molars were used to prepare the Class V cavities at the CEJ on axial surfaces. All cavities were restored with either the resin-composite or amalgam with or without resin adhesives: dry bonding: Super-Bond D-Liner II Plus; moist bonding: All-Bond 2; and self-etch bonding: AQ Bond and Clearfil Protect Bond. Two subgroups of Super-Bond D-Liner II Plus were immersed for 14 days at 37°C either in artificial saliva (negative control) or the artificial caries solution. The other groups were soaked in the artificial caries solution. The distance of dye penetration into the adjacent enamel, cementum/dentin, and tooth-resin interfaces was measured after immersion in 0.5% basic fuchsin dye for 24 h. The tooth-resin interfacial layer was investigated using SEM. Results. No dye penetration into the tooth-resin interface was found in Super-Bond D-Liner II Plus and AQ Bond groups which demonstrated a constant hybrid layer after a chemical challenge. The leakage distance at the cementum/dentin-resin interface of All-Bond 2, Clearfil Protect Bond, and non-adhesive amalgam (positive control) groups was significantly higher than the distance of dye penetration into the adjacent demineralized root surface (p<0.05). Conclusion. Caries associated with either amalgam or resin-composite restorations can be prevented using resin adhesives which can penetrate into the intact tooth substrate to form a stable hybrid layer. With caries-free restorations, tooth vitality may be conserved lifelong.


Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1477
Author(s):  
Allegra Comba ◽  
Nicola Scotti ◽  
Tatjana Maravić ◽  
Annalisa Mazzoni ◽  
Massimo Carossa ◽  
...  

The aim of this in vitro study was to evaluate the hardness and shrinkage stress (SS) of six bulk-fill resin composites. To evaluate microhardness (MH), ten 6 mm specimens were prepared using a metal mold for each selected bulk-fill resin composite and irradiated from the top side for 40 s using an LED light. After 24 h of storage, Vickers MH was evaluated on the upper, lower and lateral sides of the specimens. SS evaluation was then performed with a universal machine, which evaluated the contraction force generated by a bulk-fill composite specimen placed between two metal cylinders during and after light curing. The results were evaluated with a one-way ANOVA test with a post-hoc Bonferroni test and linear regression analysis (p < 0.05). All materials showed a significant MH decrease between the top and bottom surfaces. However, the bulk-fill materials tested performed differently when considering lateral depth progression. ANOVA tests for SS evaluation showed that both SDR and Venus Bulk Fill had significantly lower stress during irradiation than other tested materials. Further, MH decrease became significantly lower from the top surface at different depths in each tested group. Among the different resins, Venus Bulk Fill and SDR showed not only inferior hardness, but also a significant reduction in SS.


2017 ◽  
Vol 42 (2) ◽  
pp. 155-164 ◽  
Author(s):  
F Schwendicke ◽  
JLM Kniess ◽  
S Paris ◽  
U Blunck

SUMMARY Objectives: For deep carious lesions, selective carious tissue removal (leaving soft dentin close to the pulp) is suggested. Afterward, different restoration materials, such as resin composites or glass hybrids (GHs), can be placed. Many dentists also apply setting or non-setting calcium hydroxide liners before restoration. We compared margin integrity and susceptibility for secondary caries in differently restored premolars in vitro. Methods: In 48 extracted human premolars, artificial residual lesions were induced on pulpo-axial walls of standardized cavities. Teeth were restored using a GH (Equia Forte) or adhesively placed resin composite restoration (OptiBond FL and Tetric EvoCeram) without any liner (RC), resin composite restoration with a non-setting calcium hydroxide liner (RC_NCH), or resin composite restoration with a setting calcium hydroxide liner (RC_SCH). After thermomechanical cycling, groups (n=12) were compared regarding their gingivocervical margin integrity (proportion of irregularities, microgaps, gaps &gt;5 μm, overhangs). Teeth were then submitted to a continuous culture Lactobacillus rhamnosus biofilm model. After 14 days, bacterial numbers in biofilms, along tooth-restoration margins and mineral loss (ΔZ) of secondary lesions, were determined. Results: GH and RC_NCH showed significantly higher proportions of irregularities than RC and RC_SCH (p&lt;0.05/Mann-Whitney). GH also showed significantly more gaps than alternative restorations (p&lt;0.05). Bacterial numbers and ΔZ did not differ significantly between groups (p&gt;0.05). Conclusions: GH and composites lined with non-setting calcium hydroxide showed reduced margin integrity compared with non-lined composites or composites lined with setting calcium hydroxide. This did not increase susceptibility for secondary caries.


2016 ◽  
Vol 696 ◽  
pp. 108-112
Author(s):  
Elylla Oktaviana ◽  
Retno Ardhani ◽  
Heribertus Dedy Kusuma Yulianto

Introduction. Regular dental plaque control by means of chemically and mechanically methods are among efforts to improve oral health and hygiene. Mechanical cleansing using toothbrush is still the gold standard for continually removing of dental plaque. But on the other hand, inappropriate selection of toothbrushes type selection promotes alteration on dental material restoration surface. Toothbrushes with different degree of stiffness are readily available on market and are classified as hard, medium, and soft. Mechanical friction due to regular movement of the toothbrush with various degree of stiffness was predicted as factor that related with surface roughness alteration on dental material restoration. Nowadays, resin composite material is still declared as the material of choice to repair dental hard tissue damage due to caries activity. However, it has been found that the irregularity of surface promotes bacterial adhesion and biofilm deposition, whereas the smooth surface does not favor bacterial deposition. The progress of bacterial deposition promotes secondary caries on the margin between material restoration and teeth. The aim of this in vitro study was to evaluate the influence of brushing treatment by means of three different toothbrushes on the surface of resin-based compositesExperimental. Specimens were prepared from experimental RBCs with 5 mm diameter and 2 mm thick. Specimens were divided equally into 3 different groups (group A, B, and C). Each group has 5 numbers of specimens. Group A was treated with hard toothbrush, and group B as well as C were treated with medium and soft toothbrush respectively. The toothbrush was mounted in the customized mechanically brushing machine to control the force and number of cycle during specified time. Brushing cycle and time for all groups was conducted for 1000 times of brushing in 60 minutes. Surface roughness resulted from mechanically brushing is evaluated by means of profilometer device.Results and Discussion. The results of the preliminary study shows that there is a differences of surface roughness between groups. The value of roughness varied among all group, and the highest number of roughness were found in group A (> 0.2 micrometres).Conclusions. This result implies brushing with hard toothbrush preferentially has greater risk of surface damage and become pronounce factor of secondary caries.


2021 ◽  
Vol 11 (14) ◽  
pp. 6349
Author(s):  
Regina María Del Río Carrillo ◽  
Pedro Molinero-Mourelle ◽  
Vicente Vera ◽  
Pablo Romero Villaba ◽  
Elizabeth Casañas ◽  
...  

To evaluate the bond strength of different universal adhesives on deciduous tooth dentineand their relationship with the composition and potential of hydrogen (pH). Methods: An in vitromicro push-out test on 150 samples (n = 50) per group per adhesive, namely, Adhese Universal(ADH; Ivoclar Vivadent), Futurabond U (FUT; Voco GmbH) (Test), and Scotchbond Universal withpre-conditioning (SCO; 3M) (Control), to record bond strength (BS) and type of adhesive failure.Results: The results of the different adhesives (megapascals (MPa)) varied, showing no statisticalsignificance. The corresponding averages are in MPa: ADH, 13.66 2.81; FUT, 14.48 2.88; SCO,14.98 3.96. Additionally, the frequency of type of failure was as follows: mixed (60.7%), adhesive(27.3%), and cohesive (12%). Conclusions: SCO, with a pH of 2.7, showed greater resistance tofracture, while FUT, with a pH of 2.3 and no pre-conditioning, approached the same values, being aone-step adhesive. No relationship was found between failure and type of adhesive.


Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4383
Author(s):  
Barbara Lapinska ◽  
Aleksandra Szram ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Louis Hardan ◽  
...  

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1700
Author(s):  
Atsushi Kameyama ◽  
Aoi Saito ◽  
Akiko Haruyama ◽  
Tomoaki Komada ◽  
Setsuko Sugiyama ◽  
...  

This study aimed to examine the marginal seal between various commercial temporary restorative materials and exposed dentin/built-up composite. Sixty bovine incisors were cut above the cemento-enamel junction, and half of the dentin was removed to form a step, which was built up using flowable resin composite. The root canals were irrigated, filled with calcium hydroxide, and sealed using one of six temporary sealing materials (hydraulic temporary restorative material, temporary stopping material, zinc oxide eugenol cement, glass-ionomer cement, auto-cured resin-based temporary restorative material, and light-cured resin-based temporary restorative material) (n = 10 for each material). The samples were thermocycled 500 times and immersed in an aqueous solution of methylene blue. After 2 days, they were cut along the long axis of the tooth and the depth of dye penetration was measured at the dentin side and the built-up composite side. For the margins of the pre-endodontic resin composite build-up, the two resin-based temporary restorative materials showed excellent sealing. Hydraulic temporary restorative material had a moderate sealing effect, but the sealing effect of both zinc oxide eugenol cement and glass-ionomer cement was poorer.


2020 ◽  
Vol 8 (10) ◽  
pp. 454-459
Author(s):  
Bhalla V. ◽  
◽  
K. Goud M. ◽  
Chockattu S. ◽  
Khera A ◽  
...  

Background:Dentin bonding is an ever-evolving field in adhesive dentistry. With the introduction of newer systems into the market, there is a crucial need to test their efficiency in terms of bond strength. Dual-cured adhesives in theory may provide for a better degree of conversion as compared to conventional light-cured adhesives .Thus, the aim of this study was to compare the shear bond strength of three different self-etch adhesives namely ClearfilSE bond (Kuraray), Tetric N Bond Universal (IvoclarVivadent) and Futura Bond DC (Voco) to dentin. Materials & Methods: Ninety extracted non-carious, intact human mandibular molar teeth were selected for this study. Each tooth was decoronated using a double-sided diamond disc with water coolant to a depth of 2mm from the cusp tip .The cut dentin surface was then abraded against 600-grit wet silicon carbide papers for 60 seconds to produce a uniform smear layer. The root portion of each tooth was mounted on a plastic ring using cold cure acrylic resin. Specimens were then divided into three adhesive groups of 30 teeth each, Group A: ClearfilSE Bond (Kuraray), Group B: Tetric N Bond Universal (IvoclarVivadent), Group C :Futura Bond DC (Voco). All bonding agents were used according to the manufacturers’ instructions, in combination with the resin composite Tetric N Ceram (IvoclarVivadent). The samples were thermocycled, followed by shear bond strength testing using a Universal testing machine (Hounsfield). Data were subjected to statistical analysis using one-way analysis of variance (ANOVA) (P<0.05) and Post hoc Tukey’s test for inter- and intra- group analysis respectively. Results: Clearfil SE Bond yielded the highest shear bond strength values (30.9 ±4.66 MPa) which were statistically significant, followed byTetric N Bond Universal group (29.8 ±4.34) and the lowest shear bond strength values were recorded for Futura Bond DC (18.2 ±3.13). Conclusion: Clearfil SE bond and Tetric N bond Universal can be considered as better options than Futura Bond DC.


Sign in / Sign up

Export Citation Format

Share Document