Efficiency of 4 caries excavation methods compared

This in vitro study compared the efficiency (time taken to excavate and successfully remove bacterially infected dentin) of Fluorescence Aided Caries Excavation (FACE), caries detector dye (CD), chemomechanical excavation (CS) and conventional excavation (CE). Teeth with dentin caries were assigned to 4 groups (n= 25). Caries excavation was carried out by one operator. In the FACE group, the operating field was illuminated with violet light. The operator observed the teeth through a high-pass filter and removed orange-red fluorescing areas with a slow speed bur. In the CS group, Carisolv was applied to the cavity using CS hand instruments and allowed to act for 30 seconds before caries was removed. In the CD group, caries was removed using the Caries Detector and, in the CE group, conventional excavation was carried out using visual-tactile criteria. The excavation time was recorded. Undecalcified thin slices (8 microm) were prepared, stained with giemsa and examined using light microscopy. The excavation time (median) was significantly shorter for FACE (3 minutes, 3 seconds) compared to CS (5 minutes, 8 seconds, p=0.015), CD (5 minutes, 26 seconds, p=0.003) and CE (4 minutes, 2 seconds, p=0.025). Histology showed remaining bacteria in significantly fewer (5/25) FACE samples compared to CS (15/25 p=0.004) CD (12/25 p=0.037) but not significantly fewer than CE (11/25 p=0.069). In conclusion: the excavation result with FACE is equal to CE and superior to CD and CS but requires a significantly shorter excavation time.     

Removing carious dentin using a polymer instrument without anesthesia versus a carbide bur with anesthesia

BACKGROUND: The authors describe a new rotary polymer instrument that selectively removes infected dentin. This instrument has the potential to prepare selected cavities without the need for local anesthesia (LA). Patient acceptance has not been investigated in a clinical trial. METHODS: In this open-label clinical study, the authors enrolled 20 subjects with two Class I carious lesions and randomly assigned them to receive one restoration with the polymer instrument and no LA and the second restoration with a carbide bur and LA. Both procedures were completed in one appointment. Subjects completed dental history, dental anxiety and situational pain questionnaires. At specific points during the procedure, subjects rated their perception of the intensity of cold, heat, pain, pressure, vibration, fear and anxiety. On completion of the restorative procedures and at 48-hour and one-week telephone contacts, subjects indicated which procedure they preferred. RESULTS: During treatment with the polymer instrument, subjects indicated that they experienced slightly more pain, pressure, vibration and anxiety, but not more heat, cold or fear. Immediately after the procedure, 14 (70 percent) of 20 respondents (binomial test; P = .11) said that they would prefer having no LA and use of the polymer instrument for future dental work. The number of subjects indicating this preference increased to 15 (P < .05) at both the 48-hour and one-week contacts. One subject requested rescue LA during the polymer instrument treatment. CONCLUSIONS: A significant number of subjects preferred the rotary polymer instrumentation with no LA to the carbide bur instrumentation with LA. They held this preference despite experiencing slightly, but reliably, more pain and pressure when treated with the polymer instrument. CLINICAL IMPLICATIONS: A polymer (bur-like) rotary instrument with cutting ability limited to infected dentin can be used in Class I cavity preparations without the need for LA.     

Fluorescence-aided caries excavation (FACE) compared to conventional method

A recent study showed that orange-red fluorescence in carious dentin could be used to detect residual caries (Lennon & others, 2002). This study compared the ability of a new fluorescence-aided caries excavation technique (FACE) with the conventional method. Forty extracted teeth with occlusal dentin caries were selected. The teeth were bisected longitudinally through the center of the lesion. Lesion depth and width were measured and the teeth were divided into two groups of 20, each with the same average lesion size. The tooth halves were reassembled and fixed by embedding the roots in acrylic resin. Access cavities were prepared using a high-speed handpiece and diamond fissure bur. In the FACE group, violet light (370-420 nm) was fed into the fiber optics of a slow-speed hand-piece, so that it illuminated the operating field. The cavity was observed through a 530-nm high-pass filter and orange-red fluorescing areas were removed. In the conventional group, a sharp probe was used to detect soft dentin, which was removed. One-half of each tooth was stained for bacteria using Ethidium Bromide and examined using Confocal Laser Scanning Microscopy (CLSM). Bacteria were present in significantly (p=0.037) fewer FACE samples (3) compared to conventional samples (9). It can be concluded that the new method is more effective than conventional caries excavation.     

An in vitro comparison of fluorescence-aided caries excavation and conventional excavation by microhardness testing

Objective

The aim of this in vitro study was to compare fluorescence-aided caries excavation with conventional excavation based on the Martens and Vickers hardness of dentin at the cavity floor after caries removal.

Materials and methods

In total, 20 extracted human teeth with dentin caries were bisected through the lesion center into two halves, which were assigned to either the fluorescence-aided caries excavation group or the conventional excavation group. After the treatment, embedding, mounting, and polishing, a line of indentations from the dental pulp across the sound dentin to the cavity floor was made on each sample. The data were compared with Student’s t and Mann–Whitney U tests.

Results

The calculated Vickers hardness of the sound dentin was 57?±?10 kg/mm² in the fluorescence-aided caries excavation group and 59?±?8 kg/mm² in the conventional excavation group, which is consistent with the previous studies. The absolute and relative Martens hardness measurements of the cavity floor were 224?±?93 N/mm² and 46?±?17 %, respectively, in the fluorescence-aided caries excavation group and 412?±?75 N/mm² and 81?±?14 %, respectively, in the conventional excavation group. Based on either the Martens or Vickers hardness, both the absolute and relative microhardness measurements of the cavity floor after fluorescence-aided caries excavation were significantly lower than the values obtained by conventional excavation.

Conclusion

Fluorescence-aided caries excavation showed the tissue-preserving property and was more conservative than the conventional excavation in this in vitro study.     

Quantity of remaining bacteria and cavity size after excavation with FACE, caries detector dye and conventional excavation in vitro

In this in vitro study, quantitative confocal microscopy was used to show differences in the quantity of bacteria remaining in dentin after excavation with different methods. A further parameter was the cavity volume after excavation relative to the original lesion size. Teeth with dentin caries were divided into three groups of 20 each. The caries was removed by a single operator using a slow handpiece and a round bur. In the first group, Fluorescence Aided Caries Excavation (FACE) was carried out: violet light was used to illuminate the operating field and the operator observed the cavity through a high-pass filter and removed the orange-red fluorescing areas. The second group was excavated using Caries Detector, while the third group used conventional excavation. After excavation, cavity volume was measured; samples were stained for bacteria with ethidium bromide, and they were examined using confocal microscopy under standardized conditions. The bound stain was quantified in terms of fluorescence intensity on the confocal images. Total pixel intensity was significantly lower in the FACE Group than in the Caries Detector group (p = 0.046) and in the conventional excavation group (p = 0.021). Differences in cavity volume relative to original lesion size were not statistically significant (p = 0.86, 0.35 and 0.51). Within the limitations of this in vitro study, it can be concluded that FACE is more effective in removing infected dentin without significantly increasing cavity size when compared to conventional excavation and excavation with the aid of caries detector dye.     

Evaluation of residual dentin after conventional and chemomechanical caries removal using SEM

The purpose of this in vitro study was to analyze the residual dentinal surfaces following caries removal using rotatory instruments and two chemomechanical methods (Papacárie and Carisolv), by scanning electron microscopy (SEM). Thirty primary incisors were divided into three groups, according to the caries removal method used, and their residual dentin was examined under SEM (15). After caries removal, 15 of these teeth were restored with Single Bond (3M) adhesive system and Z100 Filtek composite resin (3M). The tags of the replicas were observed under SEM. The chemomechanical caries removal methods (Papacárie and Carisolv) formed an amorphous layer, similar to the smear layer and few exposed dentinal tubules; the conventional caries removal method produced a smooth and regular dentinal surface, with typical smear layer and exposed dentinal tubules. All groups showed abundant tag formation. Scanning electron microscopy analysis revealed a difference between dentin treated with rotatory instruments and that treated with chemomechanical methods in spite of the occurrence of a similar tag formation in both groups.     

Efficiency of the Vector -system compared with conventional subgingival debridement in vitro and in vivo

OBJECTIVE: To assess the efficacy of the novel ultrasonic Vector -system system for subgingival debridement and to compare the results with conventional periodontal instrumentation in vitro and in vivo. MATERIAL AND METHODS: Forty extracted human teeth were treated in vitro: Vector -system with polishing (VP) and abrasive fluid (VA), conventional ultrasonic system (U) and hand instrument (H). At intervals of 40 s, calculus removal was assessed using a 3D laser scanning device. Eight single-rooted teeth were treated in vivo with the Vector -system or hand instruments. Subgingival plaque samples were obtained for microbiological evaluation. After extraction, residual calculus was assessed by means of digitized planimetry. RESULTS: In vitro efficiency of hand instruments was statistically higher compared with the conventional ultrasonic system (p < 0.05) and the Vector -system with no difference between U and VA (p > 0.05) and VA and VP (p > 0.05). Residual calculus following in vivo instrumentation was not different in the Vector and the hand instrument group (p > 0.05) but treatment time with the Vector -system was statistically higher (p < 0.05). A similar reduction of periopathogenic bacteria could be observed in both groups. CONCLUSION: Using the Vector -system, root surfaces can be debrided as thoroughly as with conventional instruments. However, treatment is more time consuming than conventional debridement.     

Remineralization effects of conventional and experimental ion-releasing materials in chemically or bacterially-induced dentin caries lesions

Objectives

The aim of this study was to evaluate the remineralization effects of conventional and experimental ion-releasing materials on different artificial dentin carious lesions.

Evaluation of the apical seal after intraradicular retainer removal with ultrasound or carbide bur

There are situations in which intraradicular retainers have to be removed and replaced. The objective of this research was to evaluate the apical seal after the removal of a custom cast post and core with a carbide bur or with an ultrasound apparatus. Twenty five roots of extracted human incisors were used. They were endodontically treated and prepared to receive the posts. The posts and cores were cast with 2 types of dental alloys, CuAlZn and PdAg, and were cemented with zinc phosphate cement. After 24 hours, they were removed using the two above mentioned techniques. Then, the roots had their external surface made impermeable by two layers of cyanoacrylate adhesive, leaving only the cervical area for dye penetration. The teeth were immersed in rhodamine for 24 hours. They were then cut and observed under an optical microscope and analyzed with appropriate software (Imagelab). The results were submitted to ANOVA, and they evidenced that, regarding the alloy factor, PdAg posts presented a larger mean infiltration value (2.23 +/- 0.48 mm) as compared to the posts made of CuAlZn (1.39 +/- 0.48 mm) (p = 0.025). Regarding the technique factor, there was no significant difference (p = 0.9) between the removal of the intraradicular retainer using ultrasound (1.99 +/- 0.62 mm) or using a rotating cutting instrument (1.62 +/- 0.62 mm). Under these experimental conditions, it was possible to conclude that the degree of apical leakage was directly related to the alloy type, and it was present in both techniques used.     

Comparison of the efficacy of chemomechanical caries removal (Carisolv) with that of conventional excavation in reducing the cariogenic flora

OBJECTIVES: The usage of minimally invasive procedures and attention to patient comfort are of great importance, especially for dental treatment in small children. This has led to the development of chemomechanical methods for caries removal. The aim of this study was to compare the efficacy of chemomechanical caries removal with that of conventional excavation in reducing the count of the cariogenic flora. DESIGN AND SETTING: Subjects for this study were chosen from children admitted to dental clinic for restorative procedures under general anaesthesia. SAMPLES AND METHODS: Twenty-one children (mean age 43.5 +/- 12.0 months) with early childhood caries were included in this study. Two primary teeth with comparable degrees of carious destruction were chosen in each child (n = 42) for caries removal with Carisolv' or by means of rotary instruments. Samples from carious dentine were taken with a sterile scraping instrument, then all softened dentine was removed and a second sample was taken. All samples (n = 84) were serially diluted and plated on two different nutrient agar plates. RESULTS: After 24 h of incubation, colony forming units were determined for total bacterial counts and lactobacilli. Twelve per cent of the samples from carious dentine contained more than 10(6) bacteria, 23.8% contained more than 10(5) lactobacilli. Both methods of caries removal produced a statistically significant reduction in the bacterial counts (P = 0.0001). In at least 90.5% of the samples taken after the removal, the total bacterial count was below 10(2), and in 95.2% lactobacilli fell below 10(2). CONCLUSION: These results indicate that the efficacy of chemomechanical removal of carious dentine in children by means of Carisolv' is comparable to the results obtained by conventional methods, and thus might serve as a suitable alternative.     

Comparison of chemomechanical caries removal using Carisolv or conventional hand excavation in deciduous teeth in vitro

OBJECTIVES: The purpose of the present study was to compare the efficacy of chemomechanical caries removal (Carisolv) to conventional hand excavation in deciduous teeth. METHODS: Twenty-two freshly extracted teeth with varying degree of caries were treated using both of these methods. One part of each caries lesion was prepared using the Carisolv method and the other part using conventional hand excavation. The third (middle) part was left untreated to serve as control. Histological preparations of each tooth were then made and examined in order to compare the quality of the preparations. Length and area of residual caries, microhardness of the dentine in each group and time needed for preparation were analysed. RESULTS: The results showed that there was no significant difference in the amount of residual caries in the cavity walls treated using the two methods. CONCLUSIONS: The Carisolv method was significantly more time consuming than conventional preparation using hand excavator. However, both methods removed caries efficiently.     

Effect of bur cutting patterns and dentin bonding agents on dentin permeability in a fluid flow model

This study investigated the effects of bur cutting surface roughness and bonding systems on dentin permeability. A conventional straight edged bur, cross-cut serrated bur and an extensively serrated bur were utilized with two different bonding systems. Null hypothesis was that increased surface roughness does not decrease the permeability of dentin sealing after application of bonding agents. This study incorporated a fluid flow model for measuring dentin permeability. Seventy caries-free extracted molars were used and sectioned 2 mm apical to the cementoenamel junction (CEJ). The pulp tissue was removed and the chamber cleaned using 37% phosphoric acid followed by 1:1 sodium hypochlorite solution. The specimens were mounted to plexiglass plates using cyanoacrylate cement. A flow system was established through the pulp chamber and gravity pressurized phosphate buffered saline (PBS) was forced into the chamber and the "closed system" permeability measured. Burs were used to prepare flat surfaces in dentin, and after etching with phosphoric acid, the "open tubule" permeability was determined. After applying the dentin bonding agents, fluid flow from the pulp chamber into dentin was again measured. The percentage of reduction in permeability following bonding agent application was then calculated. A two-way ANOVA found a significant (p<0.05) decrease in bonded dentin permeability in specimens prepared using the cross-cut serrated and extensively serrated bur as compared to the conventional straight-edged bur. No significant differences were detected between bonding systems and no combination of surface topography or bonding agent completely sealed the surface.     

The sensitivity and specificity of clinical assessment compared with bitewing radiography for detection of occlusal dentin caries.

PURPOSE: This prospective, cross-sectional study examined the sensitivity and specificity of clinical assessment compared to bitewing radiographs in the detection of occlusal dentin caries in permanent molars. METHODS: Subjects were 481 children aged 5-12 years from a school-based dental clinic. Occlusal surfaces of 1929, sealed and unsealed first and second permanent molars were examined clinically and scored using specific criteria. Teeth with any type of restorations or proximal caries, including preventive resin restorations, were excluded from the study. Bitewing radiographs were exposed within 4 weeks of clinical examination and were assessed for dentin radiolucencies beneath the occlusal surface. The results of the clinical examinations were correlated with those of bitewing radiographs. Information provided by the parents on history forms, including systemic fluoride exposure, was also noted. RESULTS: Of the 1833 teeth scored as clinically sound in the study, only 72 (4%) demonstrated a dentin radiolucency on bitewings, and 1761 (96%) were scored as sound. The sensitivity of the clinical examination was determined to be 0.96. In the teeth clinically scored as showing dentin caries, only 56/96 (58%) were found to have dentin radiolucencies on the radiographs. The specificity of the technique was determined to be 0.58. A positive history of a medical condition, or fluoride exposure, in the forms of toothpaste use, or water fluoridation did not affect the examination results. CONCLUSIONS: Clinical examination of cleaned and dried, sealed, and unsealed teeth has a sensitivity of 0.96 and a specificity of 0.58 in the detection of dentin radiolucencies in bitewing radiographs. Dentin radiolucencies beneath clinically sound occlusal surfaces are not significantly associated with gender, medical conditions or fluoride.     

Mystery of the separating tungsten carbide burs

Three instances of tungsten carbide bur separation, one of which resulted in the patient swallowing the separated bur head are described. This spate of bur heads separating from the shank was associated with a cold sterilising solution used for disinfection.     

Visual-tactile examination compared with conventional radiography,digital radiography,and Diagnodent in the diagnosis of occlusal occult caries in extracted premolars

PURPOSE: This laboratory study compared visual-tactile examination with conventional radiographs, digital radiographs, and laser fluorescence in the detection of occlusal occult caries on extracted premolar teeth. METHODS: Extracted premolars without obvious caries or restorations were collected from school dental clinics. Occlusal surfaces of 320 extracted premolars were examined visually with an explorer, then examined using the KaVo Diagnodent unit and scored using specific criteria. The teeth were exposed using conventional and digital radiography, respectively. The radiographs were assessed for dentin radiolucencies beneath the occlusal surface. RESULTS: Of the 320 teeth used in this study, 302 were scored as sound by visual-tactile examination. Of these, 57 (19%) demonstrated dentin radiolucency on conventional bite-wings, and 245 (81%) were scored as radiographically sound. Thus, the sensitivity and specificity values of the visual-tactile examination compared with conventional radiography were 81% and 44%, respectively. In contrast, Diagnodent produced results of 82% sensitivity and 36% specificity when compared with conventional radiography. When compared to digital radiography, the sensitivity and specificity values of the visual-tactile examination were 90% and 44%, respectively. In contrast, when compared to digital radiography, Diagnodent showed a very low specificity of only 32%, although sensitivity was still high at 91%. Differences in specificity among the techniques were statistically significant (P < .03), whereas differences in sensitivity were not (P > .01). CONCLUSIONS: Although the diagnosis of occult dentinal caries may be further enhanced by the Diagnodent, a combination of visual-tactile examination and either conventional or digital radiography should identify over 80% of lesions.