Clinical performance of a glass-hybrid system in comparison with a resin composite in two-surface class II restorations: a 5-year randomised multi-centre study.

OBJECTIVE: To evaluate the 5-year clinical performance of a glass hybrid restorative system and a nano-hybrid resin composite in moderate to large two-surface class II cavities. MATERIALS AND METHODS: This study was carried out by dental schools in Zagreb, Croatia; Izmir, Turkey; Belgrade, Serbia; and Milan, Italy. A total of 180 patients requiring two class-II two-surface restorations in the molars of the same jaw were recruited. The teeth were randomly restored with either a nano-hybrid resin composite (Tetric EvoCeram, Ivoclar Vivadent) or a glass-hybrid material (EQUIA Forte, GC). During the 5-year follow-up, two calibrated evaluators at each centre scored the restorations annually using the FDI-2 scoring system. The survival rates were calculated using the Kaplan-Meier method and compared using non-parametric matched pair tests (p < 0.05). RESULTS: There were no statistically significant differences between the overall survival and success rates of the two types of restorations (p>0.05). The success rates (FDI-2 scores 1-3) for EQUIA Forte were 81.9% (average annual failure rate: 3.9%) and 90.7% for Tetric EvoCeram (average annual failure rate: 1.9%). The survival rates (FDI-2 scores 1-4) for EQUIA Forte and Tetric EvoCeram were 94.5% and 94.4%, respectively, with an average annual failure rate of 1.1%. CONCLUSIONS: In terms of success and survival rates, both the glass-hybrid restorative system and the nano-hybrid resin composite have been shown to perform satisfactorily. CLINICAL RELEVANCE: The results of this study indicate that EQUIA Forte can be one of the therapeutic options for moderate to large two-surface class II restorations of posterior teeth.

Assessment of the Prevalence of Middle Mesial Canal in Mandibular First Molar: A Multinational Cross-sectional Study with Meta-analysis.

BACKGROUND: An additional canal found in the mandibular first molar (M1M) is the middle mesial canal (MMC), which is often missed during root canal treatment. In this study, the prevalence of MMC in M1M on cone-beam computed tomography (CBCT) images was evaluated in 15 countries, along with the effect of some demographic factors on its prevalence. METHODS: Deidentified CBCT images were scanned retrospectively, and the ones including bilateral M1Ms were included in the study. A written and video instruction program explaining the protocol to be followed step-by-step was provided to all observers to calibrate them. The CBCT imaging screening procedure consisted of evaluating three planes (coronal, sagittal, and axial) after a 3-dimensional alignment of the long axis of the root(s). The presence of an MMC in M1Ms (yes/no) was identified and recorded. RESULTS: In total, 6304 CBCTs, representing 12,608 M1Ms, were evaluated. A significant difference was found between countries (P < .05). MMC prevalence ranged from 1% to 23%, and the overall prevalence was 7% (95% confidence interval [CI]: 5%-9%). No significant differences were found between the left and right M1M (odds ratio = 1.09, 95% CI: 0.93, 1.27; P > .05) or between genders (odds ratio= 1.07, 95% CI: 0.91, 1.27; P > .05). As for the age groups, no significant differences were found (P > .05). CONCLUSIONS: The prevalence of MMC varies by ethnicity, but it is generally estimated at 7% worldwide. Physicians must pay close attention to the presence of MMC in M1M, especially for opposite M1Ms, due to the prevalence of MMC being significantly bilateral.

Comparison of Different Universal Adhesive Systems on Dentin Bond Strength.

Over the past few decades, adhesive dentistry has advanced significantly. In light of minimal-invasive dentistry, this novel technique advocates a more conservative cavity design that relies on the efficiency of present enamel-dentine adhesives. The study aimed to address the scientific deficit in understanding the long-term bonding performance of universal adhesives and to provide a new clinical solution with desirable bond strength to dentin. The dentin bond strength of three bonding agents, G2-Bond Universal (GC), Clearfil SE Bond (Kuraray), and Scotchbond Universal Plus (3M ESPE), was evaluated following various storage and etching modes. The UltraTester (Ultradent) bond strength testing machine was used to assess shear bond strength. The results showed that thermal cycling and the choice of adhesive system significantly affected the shear bond strength (p = 0.018 and p = 0.001, respectively). Among the three adhesives, Scotchbond Universal Plus had the lowest bond strength value (mean value = 24.78 MPa), while G2-Bond Universal was found to have desirable shear bond strength to dentin compared to the other adhesives, even after one year in the oral environment (mean value = 35.15 MPa). These findings imply that the HEMA-free universal adhesive G2-Bond Universal is the most effective universal adhesive for clinical practices, particularly when applied in the self-etch mode.

The Effect of a Green Smoothie on Microhardness, Profile Roughness and Color Change of Dental Restorative Materials.

Acidic drinks are known to exert negative effects on the surface properties of dental restorative materials. However, the effect of increasingly popular green smoothie drinks has not been addressed so far. The present study investigated the effect of cyclic immersions (5 min daily over 30 days) in a green smoothie drink on the surface properties of contemporary dental restorative materials, including resin composites, an alkasite, and a glass hybrid. Vickers microhardness, profile roughness, and perceptible color change in the CIE L* a* b* color space were evaluated as clinically relevant properties of the material surface. After 30-day green smoothie immersion, microhardness values either decreased by 8-28% (for resin composites) or increased by up to 91% (for glass hybrid). The increase in profile roughness (Ra parameter) of smoothie-immersed specimens was 7-26 times higher compared to the control group. The perceptible color change (ΔE*) in the smoothie group was 3-8 times higher compared to the control group. Overall, this study demonstrated that daily exposure of dental restorations made from resin composites, alkasites, and glass hybrid materials to a green smoothie drink can significantly accelerate material degradation, which is reflected as surface softening, as well as higher roughness and higher perceptible color change.

Efficacy of Reciprocating Instruments in the Removal of Bioceramic and Epoxy Resin-Based Sealers: Micro-CT Analysis.

The objective of this study was to evaluate the efficacy of reciprocating instruments in the removal of bioceramic and epoxy resin-based sealers using micro-CT analysis. Root canals of 40 extracted human teeth were instrumented with a size R25 Reciproc instrument. Specimens were randomly divided into two groups (n = 20) according to the root canal filling material. In the first group, root canals were obturated with AH Plus sealer and Reciproc R25 gutta-percha. In the second group, a combination of bioceramic gutta-percha (TotalFill BC) and bioceramic sealer (TotalFill BC) was used. After one week, the retreatment of all specimens was performed using Reciproc instruments. To analyze the differences in the filling remnants, specimens were scanned in a micro-CT device after obturation and after the retreatment procedure. Statistical analysis was performed using the Mann-Whitney U test (p < 0.05). A combination of bioceramic sealer and bioceramic gutta-percha was more effectively removed from canals using a reciprocating instrument, with a filling remnants volume of 4.01 ± 3.13 mm3, in comparison to the combination of epoxy resin-based sealer and gutta-percha (6.96 ± 2.70 mm3) (p < 0.05). A reciprocating instrument was more effective in removing bioceramic sealers than epoxy resin-based sealers, although none of the root canal filling materials were completely removed from the root canals.

The Pattern of Antibiotic Prescribing by Dental Practitioners in Zagreb, Croatia.

BACKGROUND: Bacterial resistance is considered a consequence of misuse or overuse of antibiotics. Dentistry significantly contributes to this increasing public health problem. The aim of this cross-sectional study was to examine the pattern of antibiotics prescribed by Croatian dentists in Zagreb area. METHODS: Out of 220 Doctors of Dental Medicine (DMDs) from Zagreb 110 responded to survey. Prior to the research an ethical approval was obtained. Participants were directly contacted. The questionnaire consisted of two parts: general data on DMDs and the part concerning indications, duration, type and dosage of antibiotic therapy. Data were processed using MS Excel and SPSS for Windows, Version 17.0. Statistical significance was tested by Fisher's exact test, chi-square test, Mann-Whitney U test and Spearman's rank correlation at the level of statistical significance p<0.05. RESULTS: During the period of two months, the doctors prescribed antibiotics to 1,500 patients, 690 (46%) were men and 810 (54%) women. The most often prescribed antibiotics were penicillin (72.5% of patients), represented mostly by amoxicillin in combination with clavulanic acid (57.6%). The most common indication for the prescribed antibiotics was periapical or periodontal abscess (44%). Definite clinical indication (71.2%) was stated as the most common reason for antibiotic prescription. Antibiotic therapy usually lasted 7 days (62.9%). The doctors prescribed daily doses of antibiotics according to the instructions for the use of specific drugs. CONCLUSION: The examined subjects prescribe antibiotics according to the curriculum taught at the School of Dental Medicine for majority of types, doses and duration of the treatments, although antibiotics over-prescription in cases without medical indication was observed. The national guidelines on antibiotic regimens are required in order to reduce unnecessary antibiotic use.

The Oral Status of Adult Population in the Croatian Town of Knin: a Cross Sectional Study.

THE AIM: Epidemiologic studies in many countries show uneven distribution of oral diseases (primarily caries) within the population. This is why more studies are oriented towards specific regions or subpopulations instead of large scale national surveys. The major purpose of this cross sectional study was to obtain relevant data about the oral status of the population of Knin and its surroundings according to the WHO criteria. SUBJECTS AND METHODS: The study included 414 participants aged between 18 and 65. The recorded variables included general anamnestic data, extraoral status, oral mucosa status, temporomandibular joint status, dental, periodontal and prosthetic status, and the need for dental restoration. The comparison between different groups regarding age, gender, educational level and origin was made. RESULTS: DMFT index was 17.3 - with on average 1.7 caries, 6.2 fillings, and 9.4 teeth extracted. SiC index equaled 26.4. The difference was significant regarding the level of education and age (p<0.001). The percentages of individuals with the highest CPI scores from 0-4 were 27.3, 16.9, 36.5, 16.4 and 2.9%, respectively. The difference between the age groups in CPI scores was statistically significant, while the differences according to the gender and origin were not significant (p=0.001). CONCLUSION: The population of Knin and the surrounding area exhibited very bad oral status which can be attributed to the consequences of the war in the 1990-ies, the economic transition, and the lack of national program for oral health promotion.

The Level of Anxiety and Pain Perception of Endodontic Patients.

OBJECTIVES: to compare the level of anxiety reported by patients and assessed by dentists. Also, the expected and actual pain during the treatment perceived by the patient and dentist were assessed. METHODS: sixty six endodontic patients filled in two questionnaires, prior to and after the treatment, so did their therapists. The first set of questions for patients was regarding demographics, the frequency of dental visits, the level of anxiety and expectations about the level of pain. Before the treatment, dentists estimated the level of patients' anxiety and the expected intensity of pain. After the treatment, the patients evaluated the level of experienced pain and dentists' empathy during the treatment, while dentists reassessed the intensity of patients' pain.The data were statistically analysed by t-test for paired samples and by Spearmans's Rho correlation coefficient at level of significance set at 0.05. RESULTS: Patients' expectation of pain intensity was higher than the actual pain during the treatment (t-test=3.540, p=0.001). There was no difference in the level of pain which dentists expected and their perception of pain during the procedure. There was a statistically significant correlation between the patients' level of anxiety and recognition of it by dentists (Spearman Rho=0.460, p<0.001). A higher level of anxiety increased the expected intensity of pain (Spearman Rho=0.401, p=0.001). Actual intensity of pain was not significantly associated with dental anxiety (Spearman Rho=0.080, p=0.524). CONCLUSION: Since the level of dental anxiety was associated with the increased intensity of expected pain, a vicious cycle of pain and anxiety may be terminated by giving positive information to the patient before and during endodontic procedures.

Marginal leakage of class V cavities restored with silorane-based and methacrylate-based resin systems.

UNLABELLED: The aim of this study was to compare the microleakage of class V cavities restored by silorane resin with those restored by the methacrylate resin system. Sixty standardized class V cavities were prepared on premolars. The teeth were restored with Filtek(TM) Silorane and Silorane(TM) System Adhesive, Filtek(TM) Silorane and Adper(TM) Easy One and Filtek(TM) Supreme XT and Adper(TM) Easy One. The area and the depth of dye leakage were measured. Considering dye leakage area, the best results were achieved in group I (mean-M=0.114±0.083 mm(2)), then in group III (M=0.384±0.480 mm(2)) and finally in group II (M=5.389±6.587 mm(2)). Considering the depth of dye leakage, there was a significant difference between group I (mean rank-m.r.=1.23±0.44 mm) and II (1.98±0.83 mm), group II and III (1.23±0.40 mm). In this study silorane composite and its adhesive showed less microleakage than the methacrylate composite, and it showed compatibility only with its assigned adhesive. CLINICAL SIGNIFICANCE: Less microleakage of silorane restorations could provide better and long lasting composite fillings.

The effects of bluephase LED light on fibroblasts.

OBJECTIVE: The aim of this study was to evaluate the effect of Bluephase light emitting diode (LED) light on cell viability, colony-forming ability and proliferation in V79 cell culture and to determine how much the temperature of the nutrient medium rose. METHODS: The investigation included a low (L), soft start (S) and high (H) illumination mode for 20, 40 and 80 seconds. The viability was determined by the trypan blue exclusion test, colony-forming ability by counting colonies 7 days after exposure and cell proliferation by the cell counts on 5 post-exposure days. The temperature change during illumination was recorded (0.1°C sensitivity). RESULTS: In each experimental condition, 90-95% of the cells were viable, which was in the same range as the controls. Colony-forming ability was not found to be significantly lower (P<.05). A significant decrease in proliferation was recorded on the 4th post-exposure day with S and H irrespective of time, on the 3(rd) day with S for 80 s and H for 40 and 80 s, and with S and H for 80 s on the 2(nd) day (P<.05).The temperature rise was significant with S (P<.05) and H (P<.05), irrespective of exposure duration. CONCLUSION: Dependent on total energy density, LED blue light affects the mitotic activity of cells in its path to a certain extent. Altered mitotic activity was not noted with illumination at the low power mode (intensity of 421.7 ±1.1 mW/cm(2)). The greatest temperature rise was 8.3 °C and occurred at the highest intensity and exposure duration.

Caries prevalence and periodontal status in 18th century population of Pozega-Croatia.

OBJECTIVE: The aim was to examine dental and periodontal status of adult Croatian 18th century population and compare the results with available literature data. MATERIALS AND METHODS: 104 specimens from the crypt of Pozega cathedral were grouped into three female and three male groups according to age. Caries was determined by visual inspection and dental probe. Ante and post mortem teeth losses were recorded. Periodontal status was determined according to the length of exposed tooth root from alveolar crest to cemento-enamel junction. The presence of dehiscences and fenestrations was recorded on facial and oral plate of alveolar bone. RESULTS: The whole sample exhibited ante- and post mortem teeth loss of 19.57% and 24.91%, respectively. The teeth most frequently lost postmortem were incisors. The canines were best preserved. The frequency of caries in both jaws was the highest in molars (26.63% in maxilla and 28.10% in mandible), whilst central incisors exhibited the least carious lesions (11.59 and 1.92%). The most frequently affected surfaces were occlusal, then proximal and facio-oral. The percentage of teeth with either moderate or considerable bone loss was higher in females. The frequency of considerable bone loss increased significantly with age. The frequency of dehiscences was 3.11%. It was higher in maxilla than in the mandible. The frequency of fenestrations was 5.65% and it was significantly higher in maxilla. CONCLUSIONS: The results demonstrate poor oral health amongst 18th century population of continental Croatia, exhibiting high antemortem teeth loss, high periodontal disease frequency and occlusal and proximal caries frequency.

A three-dimensional evaluation of microleakage of class V cavities prepared by the very short pulse mode of the erbium:yttrium-aluminium-garnet laser.

The aim of this study was to evaluate microleakage along resin restoration in cavities prepared with an erbium:yttrium-aluminium-garnet (Er:YAG) laser, with and without acid etching, and to compare it with that in diamond-drilled cavities. Thirty intact molars were divided into three equal groups. In the teeth in group I, class V cavities were prepared with a diamond drill. Cavities in groups II and III were prepared with an Er:YAG laser (400 mJ/15 Hz for enamel and 250 mJ/10 Hz for dentine). The cavities in groups I and II were acid-etched and adhesive and flowable composite were applied to all cavities. The specimens were first immersed in dye for 24 h and then in 5% nitric acid for 72 h for softening. The fillings were extracted and photographed through a dissecting microscope. The leakage area was measured with specially designed software. The Kruskal-Wallis test showed that the best ranking was group II [mean range (m.r.) = 27.46], followed by group I (m.r. = 33.48) and, lastly, group III (m.r. = 45.15). The differences between groups I and III (P = 0.023) and between groups II and III were statistically significant (P = 0.080). The least microleakage was found in those cavities prepared by Er:YAG laser and subsequently acid-etched, whereas the most leakage was in the lased cavities that had not been etched; the traditional diamond-drilled acid-etched cavities produced medium leakage.

Ablative potential of the erbium-doped yttrium aluminium garnet laser and conventional handpieces: a comparative study.

OBJECTIVES: To compare the ability of the Variable Square Pulse technology (VSP-technology)-based erbium-doped yttrium aluminium garnet (Er:YAG) laser working in maximum speed (MAX) mode (1000 mJ, 300 micros, 20 Hz) and the high-speed handpiece to ablate enamel, to compare the ability of for the VSP-technology-based Er:YAG laser working in MAX mode and the low-speed handpiece to ablate dentin, and to analyze in vitro effects of Er:YAG ablation of enamel and dentine surfaces using scanning electron microscopy (SEM). BACKGROUND DATA: A VSP-technology-based Er:YAG laser operating in MAX mode should be appropriate for achieving the maximum ablating speed in hard dental tissues. MATERIALS AND METHODS: The experiment was conducted on extracted, cleaned, sterilized human molar teeth. Cavity preparations were made in hard dental tissues using the VSP-technology Er:YAG laser in MAX mode, in enamel using the high-speed handpiece, and in dentin using the low-speed handpiece at different time intervals. A laser triangulation profilometer was used to determine cavity volumes. The cavity surfaces of five specimens were examined using SEM. RESULTS: The Er:YAG laser removed a volume of enamel that was 3.3 times as large as that removed by the high-speed handpiece in the same period of time. In dentin, the Er:YAG laser removed 8 to 18 times as much volume as the steel bur in the same period of time. The Er:YAG ablation rate in dentin was faster than in enamel. SEM of laser prepared cavities showed a well-defined surface, free of the smear layer. CONCLUSIONS: The VSP-technology-based Er:YAG laser, working in MAX mode, is more efficient than mechanical drills for enamel and dentin ablation.

The temperature changes in the pulp chamber during cavity preparation with the Er:YAG laser using a very short pulse.

OBJECTIVE: The aim of this study was to examine the temperature changes in the pulp chamber during cavity preparation with the Er:YAG laser (2940 nm) with a very short pulse (VSP). MATERIALS AND METHODS: Nine groups of 10 intact molars each were used. One root of each sample was amputated and a thermocouple was inserted into the chamber. Class V cavity preparation in enamel was performed, and then preparation was performed in dentine. The enamel was lased with 400, 360, and 320 mJ in contact mode using a VSP with a duration of 100 microsec. The diameter of the fiber tip was 950 microm. Frequencies of 10, 12, and 15 Hz were used, and the total time of irradiation was 10 sec. The dentine was irradiated with 340, 280, and 200 mJ at 10, 8, and 5 Hz for 7 sec. Cooling was done with a water spray (73 psi and 50 mL/min). The differences were tested by MANOVA and the Bonferroni post hoc test. RESULTS: The highest rise in temperature in the pulp was achieved after enamel irradiation with 400 mJ and 15 Hz (1.99 +/- 0.28 degrees C), and the lowest was after irradiation with 320 mJ and 10 Hz (0.70 +/- 0.18 degrees C). In dentine the highest temperature increase was achieved with 340 mJ and 10 Hz (1.37 +/- 0.42 degrees C), and the lowest was with 200 mJ and 5 Hz (0.43 +/- 0.18 degrees C). Two-way analysis of both enamel and dentine showed that the influence of energy on temperature increase was stronger than that of frequency. CONCLUSION: Cavity preparation with an Er:YAG laser using VSP mode in vitro did not cause significant increases in temperature in the pulp chamber of human molars.

Vibrations produced during erbium:yttrium-aluminum-garnet laser irradiation.

The purpose of this study was to evaluate vibrations induced by an erbium:yttrium-aluminum-garnet (Er:YAG) laser in the non-contact mode and compare the vibrations with different pulse durations and energy parameters. The experiment was conducted on an extracted tooth built up in silicone impression material. The vibrations were measured by piezoelectric accelerometer for a super-short pulse (SSP), a very short pulse (VSP), and a short pulse (SP) at a frequency of 5 Hz for 1 s. For VSP and SP, the energy parameters tested were 200 mJ, 300 mJ, and 400 mJ. Measurements were performed 15 times for each individual irradiation energy level. The highest values of vibrations were measured for SP (0.160 +/- 0.04 m/s(2)), and the lowest were measured for VSP mode at the energy parameter 200 mJ (0.05 +/- 0.02 m/s(2)). There was a statistically significant (P < 0.01) difference between the various laser pulse modes (SSP, VSP, SP) at different energy parameters. At energy levels of 300 mJ and 400 mJ, the least amount of vibration during cavity preparations with the non-contact Er:YAG laser was produced by SSP mode.

Dose- and mode-dependent effect of halogen dental curing blue light on the V79-cell line.

The aim of this study was to evaluate the time and dose dependent effect of halogen light from dental curing unit on the cell viability, colony-forming ability and proliferation of the V79 cell culture. The investigation included the medium mode (M), exponential (E) and standard (S) illumination mode for 20, 40 and 80 seconds. The viability was determined using the trypan blue exclusion test. Colony forming ability was assessed by colony count on post-exposure day 7. Cell proliferation was determined by cell counts during five post-exposure days. The viability of cells was not affected by blue light in view of exposure time and modes. Colony forming ability in treated cells was slightly, but not significantly lower than in control cells. Cell proliferation was lower in cells exposed to the M mode for 80 s on post-exposure day 3 and 4 (p < 0.05). On the same post-exposure days, the proliferation of cells exposed to modes E and S, showed a significant inhibition after 20, 40 and 80 s of exposure (p < 0.05). Disrupted cellular functionality and no significant decrease in colony forming ability of V79 cells in addition to time- and dose dependent significant inhibition of cell proliferation might be ascribed to the photocuring blue light activity and/or changes in temperature during the course of experiment in vitro.

In vitro study of the variable square pulse Er:YAG laser cutting efficacy for apicectomy.

BACKGROUND AND OBJECTIVES: Variable square pulse (VSP) Er:YAG laser should be quicker than older Er:YAG lasers. The objectives were: (1) comparison of VSP laser and mechanical handpiece efficacy for apicectomy and (2) determination of optimal pulse width/energy/frequency combination. STUDY DESIGN/MATERIALS AND METHODS: Sixty extracted, single-rooted mature human teeth with round apical parts were instrumented, root filled, cleaned, and divided into four groups. Apical 2 mm of each root were apicectomized with mechanical handpiece and Er:YAG laser with three different settings (LaserA = 200 mJ/300 microseconds/ 8 Hz; LaserB = 200 mJ/100 microseconds/8 Hz; LaserC = 380 mJ/100 microseconds/20 Hz). Timing results were statistically compared. RESULTS: LaserC was the most efficient setting. Differences between groups were significant except between LaserC-Mechanical and LaserA-LaserC (P < 0.05). CONCLUSIONS: VSP Er:YAG laser used for apicectomy is slower by a factor of 7-31 than mechanical handpiece, but treatment outcome is acceptable. Optimal settings for apicectomy with VSP laser are 380 mJ/100 microseconds/20 Hz.