Alveolar Block Research Articles

Effect of bleaching agents on hardness, surface roughness and color parameters of dental enamel.

BackgroundIn this study was evaluated the effect of carbamide peroxide (CP) and hydrogen peroxide (HP) in different concentrations on hardness, roughness, and color parameters (color change - ΔE, lightness - ΔL, and yellow-blue axis - Δb) of bovine teeth. Material and MethodsFifty square dental blocks (7 x 7 x 2 mm) were submitted to initial readings of Knoop hardness, surface roughness (Ra), and color parameters. Specimens were divided into 5 groups (n = 10): control group was kept in artificial saliva during the experimental period; CP 20% was bleached for 2 h daily for 14 days, HP 9.5% was bleached for 30 min daily for 14 days, HP 38% the bleaching gel was applied for 15 min, gel was removed and it was reapplied for two more times, the bleaching session was repeated for another 2 times every 7 days, totaling three sessions, and in CP 45% three sessions of 30 min each were performed of 7 in 7 days. All groups after the bleaching procedures had the bleaching gel removed, washed, and kept in artificial saliva. At the end of bleaching treatment, the hardness, roughness, and color parameters (ΔE, ΔL, and Δb) were re-evaluated. Data were analyzed by ANOVA, Tukey, and Dunnett tests (α = 0.05). ResultsBleaching promoted a reduction in hardness, the CP 45% showed the lowest hardness and the CP 20% the highest, the HP 9.5% and HP 38% showed intermediate values of hardness. Bleaching agents did not affect the roughness. CP 20% and HP 38% promoted the highest values of ΔE and higher reduction of yellowish tone of tooth. Lightness increase after bleaching treatment for all groups. ConclusionsAll the bleaching agents tested showed effectiveness, but with reduced hardness. Key words:Carbamide peroxide, hydrogen peroxide, tooth whitening, hardness, roughness.

Effect of mouth rinses on tooth enamel surface

This study aims to evaluate the effect of mouth rinses on the color, microhardness, and surface roughness of tooth enamel. Sixty dental blocks were collected from human third molars and divided in five groups (n = 12): the control group (CG) without immersion in mouth rinse, Listerine Zero, Colgate Plax Fresh Mint, Listerine Whitening, and Colgate Luminous White. The groups were subjected to initial color analysis; the microhardness and roughness of the enamel surfaces were evaluated. Next, the samples were subjected to immersion in mouth rinses or brushing with conventional fluoride toothpaste (CG) according to the manufacturer's instructions; after a 12-week treatment, the color, microhardness, and roughness were once again assessed and compared with the initial analysis. Data were tabulated and analyzed through a two-way analysis of variance (ANOVA) (color and roughness) followed by Tukey's test. Microhardness was analyzed through the Kruskal-Wallis test followed by Dunn's test; the level of significance was 5%. All groups immersed in mouth rinses had a higher level of microhardness loss than CG; additionally, all groups showed changes in the enamel surface. Enamel surface loss was observed using a roughness test, and the mouth rinses promoted a higher level of color changes than CG. Given the results, it can be concluded that the mouth rinses led to significant changes in tooth enamel.

Comparison of the efficacy of a standard inferior alveolar nerve block versus articaine infiltration for invasive dental treatment in permanent mandibular molars in children: a pilot study.

To determine whether there is a clinical difference between an inferior dental block (IDB) using 2% lidocaine and a buccal infiltration (BI) using 4% articaine, when anaesthetising mandibular first permanent molars in children. Patients aged 8-15years who required invasive dental treatment on a lower molar tooth were randomised. The patient and dental operator were blind to the type of LA used. The patient used a visual analogue scale to record their experience of pain during injection and treatment. Twenty six teeth were anaesthetised (13 articaine, 13 lidocaine). When using an IDB, all treatment was completed successfully. On one occasion, anaesthesia was deemed unsuccessful when using a BI of articaine. There was no statistical difference in the mean VAS for the perceived pain of injection or treatment. This study showed that invasive dental treatment on a mandibular molar tooth can be completed successfully in children using a BI of articaine. In addition, the perceived pain of injection and treatment when using a BI of articaine is comparable to an IDB with lidocaine.

The preliminary study based on milling dental glass ceramics with visible and infrared picosecond laser pulse

In this study, a high-power picosecond pulsed laser in non-contact glass ceramics fabricating model was investigated based on the CAD/CAM system. Aiming to reduce the wear cost of diamond milling tools and improve the cutting efficiency and precision in the traditional manufacture of all-ceramic dental restorations, the picosecond pulsed laser (1064-nm or 532-nm wavelength) was tested for cutting three dental ceramic blocks. The relationship of laser pulse repetition or laser parameters to the ceramic remove rates was demonstrated. The remove rates of 20-W picosecond 1064-nm laser reached 0.115 mm3/s, 0.126 mm3/s, and 0.760 mm3/s for cutting VITA Mark II, IPS e.max CAD, and LAVA Ultimate respectively. The roughness and edge breakage were 5.85 μm and 15.59 μm (VITA Mark II), 3.54 μm and 14.27 μm (IPS e.max CAD), and 6.79 μm and 16.58 μm (LAVA Ultimate) respectively when high-power pulsed laser milled dental ceramics. This study verified the feasibility and practicability of the picosecond pulsed laser used for dental ceramic block milling. However, further studies on femtosecond laser’s milling efficiency and precision and the comparison of the laser milling with conventional diamond-based CAD/CAM are necessary in order to find out the manufacturing advantages of high-power pulsed laser milling system used for dental ceramic restorations.

Influence of processing variables on scratch and shrinkage behaviors and translucency of dental zirconia

AbstractScratch tests were performed on porous 3 mol% Y2O3‐stabilized zirconia dental blocks to relate compaction processing and partial sintering temperature to shrinkage and machinability of the blocks and microstructures and transmittance after full sintering. Scratch hardness of the blocks varied with increasing loads, and the variation was related to the sequential events of densification, densification and cleaving, disruption of the densified region, and chipping and longitudinal cracking. The shrinkage during final sintering was inversely proportional to the compact pressure and temperature with compact pressure having a greater impact. In contrast, the transmittance of fully sintered blocks depended largely on the partial sintering temperature because it governed the number and size of pores after completion of the sintering. Based on the influence of the variable on scratch hardness, a scratch response measure that possibly reflects the machinability of porous CAD/CAM blocks was proposed.

Comparative Evaluation of Mechanical Properties and Wear Ability of Five CAD/CAM Dental Blocks.

This study compares the mechanical properties and wear ability of five CAD/CAM (computer-aided design/computer-aided manufacturing) millable dental blocks. All the discs, including Amber Mill Hybrid, Vita Enamic, Katana Avencia, Lava Ultimate, and Amber Mill, were cut in dimensions of 1.2 mm in thickness and 12 mm in diameter, polished to a machined surface, and immersed in distilled water for seven days. Vickers hardness was measured and the indentations were observed using microscope. The discs were brushed under a 150 g load. Mean surface roughness (Ra) and topography were determined after 100,000 cycles. Finally the biaxial flexure strength of the discs was measured and the broken surfaces were observed using scanning electron microscopy (SEM). The data was subjected to Weibull analysis. All data were analyzed by one-way analysis (ANOVA). The results of Vickers hardness are shown as: Amber Mill > Vita Enamic > Amber Mill Hybrid > Lava Ultimate > Katana Avencia. Katana Avencia showed the highest volume percentage reduction and the roughest surface after toothbrushing. The biaxial flexural strength is shown as: Amber Mill > Katana Avencia > Lava Ultimate > Amber Mill Hybrid > Vita Enamic. All the tested materials exhibited varying degrees of mass loss and surface roughness. The properties of the composite materials are related to the filler content, filler volume, and polymerization methods.

Inferior dental blocks versus infiltration dentistry: is it time for change?

Dentistry is unique in that high volume surgery is undertaken efficiently on conscious patients, an anathema to most other surgical specialties who predominantly operate on unconscious patients. Local anaesthesia provides an efficient block to nociceptive pain (the first stage of the pain pathway) but only addresses one small part of the pain experience. Currently the inferior dental block (IDB) is the ‘go to’ standard for dental LA for mandibular dentistry despite its significant shortcomings. Unfortunately, as creatures of habit clinicians continue to practise what is taught at dental school, namely IDBs, when evolving more patient-safe practice takes time to be taken up by the workforce.Local anaesthesia blocks are inefficient in providing swift pulpal anaesthesia. Malamed stated that the rate of inadequate anaesthesia ranged from 31% to 81%. When expressed as success rates, this indicates a range of 19% to 69%. These numbers are so wide ranging as to make selection of a standard for rate of success for IDB seemingly impossible. LA blocks also increase the risk of systemic complications and they may be associated with nerve injury. Though LA-related permanent nerve injury is rare (approximately 1in 52–57K IDBs), once the injury occurs approximately 75% may resolve but the remaining 25% are untreatable. Most patients with trigeminal nerve injuries experience chronic pain in their lip, teeth and gums or tongue and gums, depending on which nerve is damaged. This is a lifelong burden that these patients find difficult to accommodate, especially when they were never warned about the possible risk.The risk of nerve injury can be mitigated by altering the block technique or by avoiding block anaesthesia altogether. With novel development in pharmacology of LA and equipment, block anaesthesia is likely to become rarely needed in dentistry.CPD/Clinical Relevance: Dentistry is a profession predicated upon causing and/or managing pain in patients. Providing effective pain control during surgery is essential but using techniques with the minimum risks is imperative.

Comparative evaluation of the mechanical properties of CAD/CAM dental blocks.

This study compares the mechanical properties of commercially available CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) millable dental blocks including Vita Enamic, Lava Ultimate, and MAZIC Duro. All the discs were cut in dimension of 1.2mm in thickness and 12mm in diameter, ground up to #1200 Sic papers and polished. The biaxial flexure strength of the ceramic discs was measured after thermocycling treatment and the broken surfaces were observed using scanning electron microscopy (SEM). The discs were brushed using a toothbrush testing machine under a 150g load. Surface roughness and morphology were determined after toothbrushing cycles. Finally, the friction and wear behavior of the materials against an opposing tooth were studied using a reciprocating pin-on-plate test configuration. The vertical loss of dental cusp was measured, and the surface image was examined using field emission scanning electron microscopy (FE-SEM). The biaxial flexural strength data were subjected to Weibull analysis. To compare the significance between the groups, all data were analyzed by one-way analysis (ANOVA). The biaxial flexural strength of the Lava Ultimate and MAZIC Duro materials is significantly higher than that of Vita Enamic. In addition, Lava Ultimate and MAZIC Duro exhibited significantly smoother surfaces than that of Vita Enamic after toothbrushing. Lava Ultimate and MAZIC Duro also showed less wear to the opposing tooth than that of Vita Enamic. In addition, Lava Ultimate possesses more suitable mechanical properties than the Vita Enamic and Mazic Duro for use in oral clinical prosthesis.

Two simple methods for surface modification of lithium disilicate dental blocks with hydroxyapatite

Two simple methods for surface modification of lithium disilicate dental blocks with hydroxyapatite

Chemical composition and roughness of enamel and composite after bleaching, acidic beverages and toothbrushing.

BackgroundIn this study was assessed the surface roughness and chemical composition of tooth enamel and composite resin after bleaching treatment, immersion in acidic beverages, and simulated toothbrushing.Material and MethodsOne hundred and twenty dental blocks (10 x 10 x 3 mm) were randomly assigned (n = 10) according to surface treatment [none (N), bleaching (B), toothbrushing (T), and B+T] and storage medium [saliva (S), whiskey (W), and orange juice (O)]: experimental groups - N+S, N+W, N+O, B+S, B+W, B+O, S+T, W+T, O+T, B+S+T, B+W+T, and B+O+T. Two bleaching sessions were conducted using 38% hydrogen peroxide (3 applications). Surface roughness was measured using a roughness tester and composition was determined by micro energy-dispersive X-ray fluorescence spectrometry (µ-EDXRF) before and after treatments. Calcium/phosphorus (Ca/P) ratio in enamel and silica (Si) content in composite were evaluated. Data were statistically analyzed by ANOVA and Tukey’s test (α = 0.05).ResultsOverall, increased values of surface roughness for enamel and composite were observed mainly after immersion in orange juice and bleaching/toothbrushing association. Moreover, this association and immersion in whiskey resulted in lower Ca/P ratio and after aging methods, bleached and bleached/toothbrushed groups showed decreased in Ca/P ratio compared to initial values. All groups showed Si content decrease at the end, except the group without surface treatment and immersed in saliva, and bleaching followed by immersion in orange juice and toothbrushing caused the highest Si reduction.ConclusionsBleaching and toothbrushing combination strengthened the effects caused by acidic drinks on roughness and chemical composition of enamel and composite. Key words:Tooth bleaching, toothbrushing, physical properties, chemical properties.

Effect of Heavy Metals Contamination from Cigarette Smoke on Sound and Caries-Like Enamel.

In this study, we sought to evaluate the influence of cigarette smoke and pH cycling on the chemical composition and surface/cross-sectional enamel microhardness. A total of 40 dental blocks obtained from bovine incisors were divided into four groups (n=10): no treatment (control); exposure to cigarette smoke (CS); exposure to pH cycling (PC); and exposure to cigarette smoke and pH cycling (CS-PC). The samples were analyzed by synchrotron radiation micro X-ray fluorescence, bench mode X-ray fluorescence, as well as surface microhardness (SMH) and cross-sectional microhardness (CSMH) testing. The SMH results were submitted to analysis of variance (ANOVA) and Tukey's test. The CSMH results were evaluated using split-plot ANOVA and Tukey's test. A high amount of Cd and Pb and traces of Ni and As were observed in enamel and dentin after exposure to cigarette smoke (CS and CS-PC). The SMH and CSMH of CS were statistically higher when compared with the control. The PC and CS-PC showed lower SMH and CSMH. We conclude that exposure to cigarette smoke promoted heavy metal deposition in enamel/dentin. In addition, it increased the enamel microhardness but did not promote a protective effect on the in vitro development of caries. The clinical significance of this work is that there is significant bioaccumulation of heavy metals from cigarette smoke on the surface and in the enamel and dentin.

Optimal Local Anaesthesia for Dentistry

Dentistry is unique in that high-volume surgery is undertaken efficiently on conscious patients, an anathema to most other surgical specialties, who predominantly operate on unconscious patients. local anaesthesia (LA) provides an efficient block to nociceptive pain (the first stage of the pain pathway) but only addresses one small part of the pain experience. Currently the inferior dental block is the "go to" standard for dental LA for mandibular dentistry, despite its significant short comings. Unfortunately, habit means that we continue to practise what is taught to us at dental school, thus, not developing safer modern LA practice.<br/> The dental syringe and deep injections are also the main triggers for fear and anticipated pain by patients expecting their dental appointment. The uptake of infiltration dentistry has been swift in implant dentistry, despite lack of an evidence base, and now other branches of specialty dentistry, general practice is awakening to the advantages of infiltration or "smart" local anaesthetic practices.<br/> Inferior dental blocks are inefficient in providing swift pulpal anaesthesia. Stanley Malamed Stated: "The rate of inadequate anaesthesia ranged from 31% to 81%, which when expressed as success rates, indicates a range of 19% to 69%. These numbers are so wide ranging as to make selection of a standard for rate of success for inferior alveolar nerve block (IANB) seemingly impossible".<br/> Any block injection is also associated with an increase in the risk of systemic and local complications (including nerve injury), possible heightened medical complications and patient discomfort and fear. Fear of deep dental injections is a key factor in dental anxiety and phobia.

Preparation of presintered zirconia blocks for dental restorations through colloidal dispersion and cold isostatic pressing

This work proposes an effective method for dispersion of zirconia suspension for dental block preparation and optimizes the cold isostatic pressing (CIP) pressure to improve the densification of slip-casted zirconia blocks. Two batches of 44wt% zirconia suspension were prepared using distilled water in a pH 2 medium containing 0.5wt% polyethyleneimine as dispersant. The first batch was sonicated for different durations (from 5min to 30min), and the second batch was dispersed through ball milling at rotational speeds of 200, 300, and 400rpm for 60, 90, and 120min. All suspensions were subjected to sedimentation test and particle size measurement. Results revealed that the optimum ultrasonication duration was 10min, which yielded the smallest particle size of 133nm. Ball milling at 300rpm for 120min achieved the maximum dispersion of particles, with an average size of 75nm. Under the optimum conditions of ultrasonication duration, ball milling duration, and ball milling speed, the particle size decreased to 48nm, which is close to the primary particle size. These dispersion techniques and parameters were selected for preparing a suspension to be consolidated into blocks through slip casting and were enhanced through CIP at pressure ranging from 100MPa to 300MPa. CIP compaction at 250MPa significantly increased the shrinkage percentage of green zirconia blocks, with pore radius decreased to 18nm. The density of zirconia pressed at 250MPa and presintered at a low temperature of 950°C was 59% of the theoretical density and was higher than that of commercial presintered blocks. Thus, CIP should be conducted under a compaction pressure of 250MPa to produce dense and homogeneous zirconia blocks.

In vitro evaluation of soft drinks containing calcium lactate

Introduction: Over the past 2 years, the soft drink industry has seen a value growth of 11%. In total, 1.3 billion people in India drink nearly 5.9 billion liters of soft drinks per year making it one of the highest soft drink-consuming countries in the world. Hence, products such as calcium lactate which efficiently reduce the erosive action of drinks should be better incorporated in soft drinks to limit its adverse effects. Aim: The objective of this study was to assess the degree of dental erosion due to soft drinks with and without the presence of 5% calcium lactate. Materials and Methods: Three soft drinks (MaazaCoca-Cola, AppyFizParleAgro, and PepsiPepsiCo) and normal water were taken. A total of 40 dental blocks were randomly allocated into four groups. Surface loss (SL) was assessed using Digital Surfometry. Surfometry readings were taken before and after adding calcium lactate in the above soft drinks for definite time intervals. Data were analyzed using SPSS version 22. ANOVA was used to assess separately degree of erosion of tooth blocks in all the soft drinks samples with and without 5% calcium lactate. The paired t-test was used to determine the degree of SL within each group before and after adding 5% calcium lactate. Results: In the present study, PepsiPepsiCo had the highest acidic pH (2.7) and showed the highest degree of erosion with a mean value of 1.55 μ ± 0.07. After adding calcium lactate, the highest acidic pH was shown by AppyFizParle Agro (4.45); however, the degree of erosion was still the highest for Pepsi with a mean value of 1.36 μ ± 0.09. Later, each group was compared for SL among themselves with and without the presence of calcium lactate. AppyFizParleAgro showed the highest degree of erosion with a mean value of 0.22 μ ± 0.08. P ≤ 0.05 was considered as statistically significant. Conclusion: The erosive action of soft drinks varies widely. The results demonstrate that the addition of 5% calcium lactate to soft drinks significantly decreased dental erosion.

Articaine-only buccal infiltrations for mandibular molar extractions: an alternative to inferior dental nerve blocks

This article assesses the efficacy of the articaine-only buccal infiltration technique (AOBIT) in providing LA for adult mandibular molar extractions. In 112 patients the AOBIT effectiveness was judged against the need for repeat or supplemental infiltrations and rescue 2% lidocaine inferior dental blocks (IDBs). Sufficient anaesthesia was achieved in 57% of patients using the AOBIT, with another 27% requiring an additional dose via the AOBIT. The remaining 16% required a rescue 2% lidocaine IDB. The AOBIT could be a suitable alternative to 2% lidocaine IDBs for routine adult mandibular molar extractions, and may subsequently reduce the incidence of LA-related nerve injury. CPD/Clinical Relevance: Debilitating nerve injury in relation to the administration of IDBs may be more common than we think. This article assesses the articaine-only buccal infiltration technique (AOBIT) as an alternative in providing local anaesthesia for routine adult mandibular molar extractions.

Elastic properties and porosity of dental blocks made from non-metal materials used for chairside CAD/CAM crowns

Elastic properties and internal structure of glass-ceramic, feldspatic ceramic, PMMA and hybrid blocks for chairside CAD/CAM dental crowns were assessed by pulsed acoustic microscopy. Elastic modulus of hybrid ceramic was 1.5 times inferior to feldspatic ceramic and glass-ceramic but almost 10 times higher than those of polymer samples. We found the presence of pores from a few to hundreds of microns in the bulk of inorganic materials samples, isolated point defects were revealed in polymer materials while in hybrid material defects were not found.

Dental Procedures.

Dental problems are a common complaint in emergency departments in the United States. There are a wide variety of dental issues addressed in emergency department visits such as dental caries, loose teeth, dental trauma, gingival infections, and dry socket syndrome. Review of the most common dental blocks and dental procedures will allow the practitioner the opportunity to make the patient more comfortable and reduce the amount of analgesia the patient will need upon discharge. Familiarity with the dental equipment, tooth, and mouth anatomy will help prepare the practitioner for to perform these dental procedures.

After bleaching enamel remineralization using a bioactive glass-ceramic (BioSilicate®)

AbstractTooth bleaching agents may weaken the tooth structure, therefore, it is important to minimize any risks of enamel and dentine damage caused by them. In this way, different materials have been used to avoid or minimize the tooth damage during bleaching. Recently, bioactive glasses have been demonstrated to be effective in mineralization of dental structures. Therefore, this study evaluated the effect of BioSilicate® (a polycrystalline bioactive glass-ceramic) after bleaching by Laser-induced breakdown spectroscopy (LIBS) technique. Bovine dental blocks with 4 × 4 × 3 mm were obtained (n = 20), sequentially embedded in epoxy resin and then polished. Bleaching was performed using 35% hydrogen peroxide (Whiteness HP). Calcium (Ca) and phosphate (P) intensity values by LIBSwere obtained before the treatment (T0, baseline – control Group), after bleaching (T1), and after BioSilicate® application (T2). The use of BioSilicate® after bleaching showed to be an optimal way to remineralize enamel surface making BioSilicate® application a promising adjunct step to avoid or minimize the mineral loss on enamel surface after bleaching.

Effect of Cigarette Smoke on Resin Composite Bond Strength to Enamel and Dentin Using Different Adhesive Systems.

To evaluate the microshear bond strength of composite resin restorations in dental blocks with or without exposure to cigarette smoke. Eighty bovine dental blocks were divided into eight groups (n=10) according to the type of adhesive (Scotchbond Multi-Purpose, 3M ESPE, St Paul, MN, USA [SBMP]; Single Bond 2, 3M ESPE [SB]; Clearfil SE Bond, Kuraray Medical Inc, Okayama, Japan [CSEB]; Single Bond Universal, 3M ESPE [SBU]) and exposure to smoke (no exposure; exposure for five days/20 cigarettes per day). The adhesive systems were applied to the tooth structure, and the blocks received a composite restoration made using a matrix of perforated pasta. Data were statistically analyzed using analysis of variance and Tukey test (α<0.05). For enamel, there was no difference between the presence or absence of cigarette smoke (p=0.1397); however, there were differences among the adhesive systems (p<0.001). CSEB showed higher values and did not differ from SBU, but both were statistically different from SB. The SBMP showed intermediate values, while SB demonstrated lower values. For dentin, specimens subjected to cigarette smoke presented bond strength values that were lower when compared with those not exposed to smoke (p<0.001). For the groups without exposure to cigarette smoke, CSEB showed higher values, differing from SBMP. SB and SBU showed intermediary values. For the groups with exposure to cigarette smoke, SBU showed values that were higher and statistically different from SB and CSEB, which presented lower values of bond strength. SBMP demonstrated an intermediate value of bond strength. The exposure of dentin to cigarette smoke influenced the bonding strength of adhesives, but no differences were noted in enamel.

Essential local anaesthetic blocks for small animal practice: dental blocks

Dental disease is common, particularly in geriatric animals, and often requiring general anaesthesia for dental procedures. The use of multimodal analgesia may help to minimise morbidity in patients as part of balanced anaesthesia, and provide effective perioperative analgesia. Locoregional anaesthesia can be used to reduce the amount of inhalational anaesthetic agent required, and provide better analgesia both during and after surgery, facilitating smoother anaesthetics and potentially better recoveries. This article will discuss the commonly used drugs, equipment, anatomy and techniques required to provide effective nerve blocks for dental procedures.