Selective carious tissue-removal strategies require specific considerations in selection of restorative materials. A tight marginal seal placed over hard dentin and sound enamel is essential. For ...selective removal of carious tissue with permanent restoration, bioactive materials, such as high-viscosity glass-ionomer cement (HV-GIC) or calcium silicates, may be preferred over caries-affected firm or leathery dentin to improve remineralization. HV-GICs have the best clinical evidence of caries-arresting effect and demonstrate sufficient longevity as long-term provisional restorations that can later be used in open or closed sandwich restorations. As with any material, oral health maintenance remains important for long-term survival of restorations.
Abstract Introduction Endodontic-related paresthesia is a potential complication despite the development of endodontic materials and techniques. We describe a case of periapical lesion-induced ...paresthesia that was successfully treated endodontically. The literature review of endodontic-related paresthesia is also presented. Methods The patient sought treatment from a general practitioner for lower lip paresthesia as the only symptom. Paresthesia was present on the left side of the lower lip extending from the mandibular midline to the second premolar both extraorally and intraorally in the area of mental nerve stem. Apical lesion of an endodontically treated second premolar with short obturation was observed radiographically. Retreatment was unsuccessful at reaching the apex; instead, swelling, pain, and extension of numbness on the region resulted, and the patient was referred to an endodontist. Results The root canal chemomechanical debridement was completed, and calcium hydroxide was placed for the follow-up. Two months later the symptoms had significantly improved, the radiograph indicated partial healing, and the tooth was obturated. The healing progressed so that the symptoms completely resolved within a year after the treatment. Conclusions Periapical pathosis might cause paresthesia with a good potential for healing after appropriate endodontic treatment. Complications might be prevented by careful preoperative examination, good quality radiographs, and good instrumentation, irrigation, and obturation techniques. However, according to the literature paresthesia might still occur. In case of treatment-related paresthesia in which apical extrusion of endodontic materials is observed, the need for surgical debridement (especially in cases of extrusion of obturation materials) should be considered within 48 hours.
Dentin bonding: can we make it last? Tjäderhane, L
Operative dentistry,
2015 Jan-Feb, 2015-01-01, 20150101, Letnik:
40, Številka:
1
Journal Article
Recenzirano
Odprti dostop
In dentin bonding, contemporary dental adhesive systems rely on formation of the hybrid layer, a biocomposite containing dentin collagen and polymerized resin adhesive. They are usually able to ...create at least reasonable integrity of the hybrid layer with high immediate bond strength. However, loss of dentin-bonded interface integrity and bond strength is commonly seen after aging both in vitro and in vivo. This is due to endogenous collagenolytic enzymes, matrix metalloproteinases, and cysteine cathepsins, responsible for the time-dependent loss of hybrid layer collagen. In addition, the hydrophilic nature of adhesive systems creates problems that lead to suboptimal hybrid layers. These problems include, for example, insufficient resin impregnation of dentin, phase separation, and a low rate of polymerization, all of which may reduce the longevity of the bonded interface. Preservation of the collagen matrix integrity by inhibition of endogenous dentin proteases is key to improving dentin bonding durability. Several approaches to retain the integrity of the hybrid layer and to improve the long-term dentin bond strength have been tested. These include the use of enzyme inhibitors, either separately or as incorporated into the adhesive resins; increase of collagen resistance to enzymatic degradation; and elimination of water from the interface to slow down or eliminate hydrolytic loss of the hybrid layer components. This review looks at the principles, current status, and future of the different techniques designed to prevent the loss of hybrid layer and bond strength.
Mild acids are known to activate dentin matrix metalloproteinase (MMPs). All self‐etching dental adhesives are acidic (pH 1.5–2.7) and may activate dentin MMPs. The purpose of this study was to ...compare the ability of several all‐in‐one adhesives to activate gelatinolytic and collagenolytic activities in powdered mineralized dentin. Powdered dentin made from human teeth was mixed with all‐in‐one adhesives (Clearfil Tri‐S Bond, G‐Bond, Adper Prompt L‐Pop) or a self‐etching primer (Clearfil SE Bond primer) for varying times and then the reaction was stopped by extracting the adhesives using acetone. Fresh untreated mineralized dentin powder had a gelatinolytic activity of 3.31 ± 0.39 relative fluorescent units (RFU) per mg dry weight (24 h) that increased, over storage time, to 87.5 RFU mg−1 (24 h) after 6–8 wk. When fresh powder was treated with acidic Tri‐S Bond, the gelatinolytic activity increased from 3.24 ± 0.70 RFU mg−1 to > 112.5 RFU mg−1 (24 h) after 20 min and then remained unchanged. Monomers with lower pH values produced less activity. There was a significant, direct correlation between gelatinolytic activity and pH, with Tri‐S giving the highest activity. Coating dentin powder with Tri‐S resin prevented fluorescent substrates from gaining access to the enzyme, even though it activated the enzyme. In conclusion, self‐etch adhesives may activate latent MMP and increase the activity to near‐maximum levels and contribute to the degradation of resin–dentin bonds over time.
Efforts towards achieving durable resin–dentin bonds have been made for decades, including the understanding of the mechanisms underlying hybrid layer (HL) degradation, manufacturing of improved ...adhesive systems, as well as developing strategies for the preservation of the HL.
This study critically discusses the available peer-reviewed research concerning the formation and preservation of the HL, the mechanisms that lead to the degradation of the HL as well as the strategies to prevent it.
The degradation of the HL occurs through two main mechanisms: the enzymatic degradation of its collagen fibrils, and the leaching of the resin from the HL. They are enabled by residual unbound water between the denuded collagen fibrils, trapped at the bottom of the HL. Consequently, endogenous dentinal enzymes, such as the matrix metalloproteinases (MMPs) and cysteine cathepsins are activated and can degrade the denuded collagen matrix. Strategies for the preservation of the HL over time have been developed, and they entail the removal of the unbound water from the gaps between the collagen fibrils as well as different modes of silencing endogenous enzymatic activity.
Although there are many more hurdles to be crossed in the field of adhesive dentistry, impressive progress has been achieved so far, and the vast amount of available research on the topic is an indicator of the importance of this matter and of the great efforts of researchers and dental material companies to reach a new level in the quality and longevity of resin–dentin bonds.
Dentin organic matrix, with type I collagen as the main component, is exposed after demineralization in dentinal caries, erosion or acidic conditioning during adhesive composite restorative ...treatment. This exposed matrix is prone to slow hydrolytic degradation by host collagenolytic enzymes, matrix metalloproteinases (MMPs) and cysteine cathepsins. Here we review the recent findings demonstrating that inhibition of salivary or dentin endogenous collagenolytic enzymes may provide preventive means against progression of caries or erosion, just as they have been shown to retain the integrity and improve the longevity of resin composite filling bonding to dentin. This paper also presents the case that the organic matrix in caries-affected dentin may not be preserved as intact as previously considered. In partially demineralized dentin, MMPs and cysteine cathepsins with the ability to cleave off the terminal non-helical ends of collagen molecules (telopeptides) may lead to the gradual loss of intramolecular gap areas. This would seriously compromise the matrix ability for intrafibrillar remineralization, which is considered essential in restoring the dentin's mechanical properties. More detailed data of the enzymes responsible and their detailed function in dentin-destructive conditions may not only help to find new and better preventive means, but better preservation of demineralized dentin collagenous matrix may also facilitate true biological remineralization for the better restoration of tooth structural and mechanical integrity and mechanical properties.
Abstract Objectives Contemporary adhesives lose their bond strength to dentin regardless of the bonding system used. This loss relates to the hydrolysis of collagen matrix of the hybrid layers. The ...preservation of the collagen matrix integrity is a key issue in the attempts to improve the dentin bonding durability. Methods Dentin contains collagenolytic enzymes, matrix metalloproteinases (MMPs) and cysteine cathepsins, which are responsible for the hydrolytic degradation of collagen matrix in the bonded interface. Results The identities, roles and function of collagenolytic enzymes in mineralized dentin has been gathered only within last 15 years, but they have already been demonstrated to have an important role in dental hard tissue pathologies, including the degradation of the hybrid layer. Identifying responsible enzymes facilitates the development of new, more efficient methods to improve the stability of dentin–adhesive bond and durability of bond strength. Significance Understanding the nature and role of proteolytic degradation of dentin–adhesive interfaces has improved immensely and has practically grown to a scientific field of its own within only 10 years, holding excellent promise that stable resin–dentin bonds will be routinely available in a daily clinical setting already in a near future.
Aim. To evaluate the regional variation in restorative treatment need among Finnish young people based on the socioeconomic factors. Materials and Methods. This cross-sectional study was conducted in ...20 garrisons of the Finnish Defence Forces in January and July 2011. The study population comprised 13,819 Finnish conscripts born in the beginning of 1990s, including females. A computer-based survey was done together with clinical oral examination to gather background information, e.g., educational status. Furthermore, average annual income of the conscript’s residence municipality was achieved from the Statistics of Finland. The zip code of the place of residence of each conscript was later extracted from the Mildoc® system. Georeferenced place of residence and income status were merged as information on provinces’ level in a dataset. The association between the outcome variable and explanatory variables was determined by using the generalized linear mixed model, and geomaps were constructed. Results. Mean D value was 1.41 ranging from 0.89 (Kymenlaakso) to 2.33 (Kainuu). Higher education and high-income level were protective factors for restorative treatment need. Restorative treatment need was also low in those areas with high (OR: 0.70, 95% CI: 0.56–0.87) and medium (OR: 0.79, 95% CI: 0.70–0.89) yearly income compared to low yearly income. The high odds for the need of restorative treatment were discovered in Northern Ostrobothnia (OR: 2.26, 95% CI: 1.53–3.33) followed by Central Ostrobothnia (OR: 2.08, 95% CI: 1.17–3.70), Uusimaa (OR: 1.55, 95% CI: 1.16–2.08), and Central Finland (OR: 1.54, 95% CI: 1.10–2.16) compared to Varsinais-Suomi. Conclusion. In conclusion, there is a significant regional variation in restorative treatment need among Finnish young people in their twenties based on the socioeconomic factors.
Periodontitis is a bacterium-induced chronic inflammation that destroys tissues that attach teeth to jaw bone. Pathologically excessive matrix metalloproteinase 8 (MMP-8) is among the key players in ...periodontal destruction by initiating type I collagen degradation. We studied MMP-8 in Porphyromonas gingivalis-induced periodontitis by using MMP-8-deficient (MMP8⁻/⁻) and wild-type (WT) mice. Alveolar bone loss, inflammatory mediator expression, serum immunoglobulin, and lipoprotein responses were investigated to clarify the role of MMP-8 in periodontitis and systemic inflammatory responses. P. gingivalis infection induced accelerated site-specific alveolar bone loss in both MMP8⁻/⁻ and WT mice relative to uninfected mice. The most extensive bone degradation took place in the P. gingivalis-infected MMP8⁻/⁻ group. Surprisingly, MMP-8 significantly attenuated (P < 0.05) P. gingivalis-induced site-specific alveolar bone loss. Increased alveolar bone loss in P. gingivalis-infected MMP8⁻/⁻ and WT mice was associated with increase in gingival neutrophil elastase production. Serum lipoprotein analysis demonstrated changes in the distribution of high-density lipoprotein (HDL) and very-low-density lipoprotein (VLDL) particles; unlike the WT mice, the MMP8⁻/⁻ mice underwent a shift toward a smaller HDL/VLDL particle sizes. P. gingivalis infection increased the HDL/VLDL particle size in the MMP8⁻/⁻ mice, which is an indicator of lipoprotein responses during systemic inflammation. Serum total lipopolysaccharide activity and the immunoglobulin G-class antibody level in response to P. gingivalis were significantly elevated in both infected mice groups. Thus, MMP-8 appears to act in a protective manner inhibiting the development of bacterium-induced periodontal tissue destruction, possibly through the processing anti-inflammatory cytokines and chemokines. Bacterium-induced periodontitis, especially in MMP8⁻/⁻ mice, is associated with systemic inflammatory and lipoprotein changes that are likely involved in early atherosclerosis.
State of the art etch-and-rinse adhesives Pashley, David H; Tay, Franklin R; Breschi, Lorenzo ...
Dental materials,
01/2011, Letnik:
27, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract Objectives : The aim of this study was to explore the therapeutic opportunities of each step of 3-step etch-and-rinse adhesives. Methods : Etch-and-rinse adhesive systems are the oldest of ...the multi-generation evolution of resin bonding systems. In the 3-step version, they involve acid-etching, priming and application of a separate adhesive. Each step can accomplish multiple goals. Acid-etching, using 32–37% phosphoric acid (pH 0.1–0.4) not only simultaneously etches enamel and dentin, but the low pH kills many residual bacteria. Results : Some etchants include anti-microbial compounds such as benzalkonium chloride that also inhibits matrix metalloproteinases (MMPs) in dentin. Primers are usually water and HEMA-rich solutions that ensure complete expansion of the collagen fibril meshwork and wet the collagen with hydrophilic monomers. However, water alone can re-expand dried dentin and can also serve as a vehicle for protease inhibitors or protein cross-linking agents that may increase the durability of resin–dentin bonds. In the future, ethanol or other water-free solvents may serve as dehydrating primers that may also contain antibacterial quaternary ammonium methacrylates to inhibit dentin MMPs and increase the durability of resin–dentin bonds. The complete evaporation of solvents is nearly impossible. Significance : Manufacturers may need to optimize solvent concentrations. Solvent-free adhesives can seal resin–dentin interfaces with hydrophobic resins that may also contain fluoride and antimicrobial compounds. Etch-and-rinse adhesives produce higher resin–dentin bonds that are more durable than most 1 and 2-step adhesives. Incorporation of protease inhibitors in etchants and/or cross-linking agents in primers may increase the durability of resin–dentin bonds. The therapeutic potential of etch-and-rinse adhesives has yet to be fully exploited.
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