PeerJ Preprints: Dentistryhttps://peerj.com/preprints/index.atom?journal=peerj&subject=3700Dentistry articles published in PeerJ PreprintsCan the levels of toothache-related interests of Google and YouTube users differ between developed and developing countries over the years?https://peerj.com/preprints/275702019-03-072019-03-07Matheus LottoPatricia EA AguirreAnna P StriederAgnes FP CruvinelThiago Cruvinel
Background: The preferences of Web users can be influenced by distinct factors of populations, such as the ability of obtaining, processing, and understanding health information adequately. In this sense, hypothetically, source-based patterns of health-related Web searches might differ between individuals from developed and developing countries, due to their educational backgrounds. This study aimed to determine the trends of toothache-related searches performed on Google Search and YouTube, regarding differences between developed and developing countries. Methods: This longitudinal study analyzed computational metadata on toothache-related interests of Internet users. Google Trends was accessed to obtain the monthly variation of relative search volume (RSV) of the topic "Toothache-Disease" on Google (G) and YouTube (YT) through 2008 to 2017. Autocorrelation and partial autocorrelation plots, ARIMA models, Kruskal-Wallis, Dunn’s and T tests were performed for evaluating trends, 12-month forecasts and the differences of annual ratios of YT/G searches between developed and developing countries, respectively (P<0.05). Results: Uptrends of RSVs were observed in both country groups over time, although 12-month forecasts tended to plateau. The volumes of searches were larger in developed countries, becoming closer to those observed in developing countries in last years. Independently of country groups, the ratios YT/G remained relatively constant throughout the period, indicating a greater interest in toothache-related information available on Google. Conclusion: In conclusion, toothache-related searches from Google and YouTube increased during the last decade. The preferences of Web users seemed to be influenced by the differences found in the availability and penetration of the Internet, and education levels between developed and developing countries.
Background: The preferences of Web users can be influenced by distinct factors of populations, such as the ability of obtaining, processing, and understanding health information adequately. In this sense, hypothetically, source-based patterns of health-related Web searches might differ between individuals from developed and developing countries, due to their educational backgrounds. This study aimed to determine the trends of toothache-related searches performed on Google Search and YouTube, regarding differences between developed and developing countries. Methods: This longitudinal study analyzed computational metadata on toothache-related interests of Internet users. Google Trends was accessed to obtain the monthly variation of relative search volume (RSV) of the topic "Toothache-Disease" on Google (G) and YouTube (YT) through 2008 to 2017. Autocorrelation and partial autocorrelation plots, ARIMA models, Kruskal-Wallis, Dunn’s and T tests were performed for evaluating trends, 12-month forecasts and the differences of annual ratios of YT/G searches between developed and developing countries, respectively (P<0.05). Results: Uptrends of RSVs were observed in both country groups over time, although 12-month forecasts tended to plateau. The volumes of searches were larger in developed countries, becoming closer to those observed in developing countries in last years. Independently of country groups, the ratios YT/G remained relatively constant throughout the period, indicating a greater interest in toothache-related information available on Google. Conclusion: In conclusion, toothache-related searches from Google and YouTube increased during the last decade. The preferences of Web users seemed to be influenced by the differences found in the availability and penetration of the Internet, and education levels between developed and developing countries.Tertiary dentine frequencies in extant great apes and fossil homininshttps://peerj.com/preprints/271152018-08-142018-08-14Ian Towle
Tertiary dentine forms when an odontoblast is directly affected by stimuli, commonly through occlusal wear. In this study the presence of tertiary dentine is recorded in three South African fossil hominin species (Australopithecus africanus, Homo naledi and Paranthropus robustus), and two extant great ape species (Gorilla gorilla gorilla and Pan troglodytes). Frequencies of tertiary dentine were calculated for each species based on macroscopic observations of teeth with dentine exposed through occlusal wear. Overall, the three hominin species have similar tertiary dentine frequencies ranging from 12% to 16.13%. In contrast, over 90% of gorilla teeth with dentine visible show tertiary dentine. Chimpanzees fall between these extremes with 47.21% of teeth affected. Species variances are not related to differences in occlusal wear. Instead, some species appear predisposed to produce tertiary dentine earlier and/or faster than other species. Therefore, tertiary dentine formation has the potential to provide useful information on fossil specimens. For example, the uniformly low rate of tertiary dentine formation in hominins may be due to thick enamel having a similar role in preventing loss of function of teeth, i.e., extending the life of a tooth. In contrast tertiary dentine is clearly an important mechanism for normal dental function in gorillas, and may have evolved to maintain sheering surfaces for masticating tough vegetation.
Tertiary dentine forms when an odontoblast is directly affected by stimuli, commonly through occlusal wear. In this study the presence of tertiary dentine is recorded in three South African fossil hominin species (Australopithecus africanus, Homo naledi and Paranthropus robustus), and two extant great ape species (Gorilla gorilla gorilla and Pan troglodytes). Frequencies of tertiary dentine were calculated for each species based on macroscopic observations of teeth with dentine exposed through occlusal wear. Overall, the three hominin species have similar tertiary dentine frequencies ranging from 12% to 16.13%. In contrast, over 90% of gorilla teeth with dentine visible show tertiary dentine. Chimpanzees fall between these extremes with 47.21% of teeth affected. Species variances are not related to differences in occlusal wear. Instead, some species appear predisposed to produce tertiary dentine earlier and/or faster than other species. Therefore, tertiary dentine formation has the potential to provide useful information on fossil specimens. For example, the uniformly low rate of tertiary dentine formation in hominins may be due to thick enamel having a similar role in preventing loss of function of teeth, i.e., extending the life of a tooth. In contrast tertiary dentine is clearly an important mechanism for normal dental function in gorillas, and may have evolved to maintain sheering surfaces for masticating tough vegetation.Is it possible to reduce file numbers of conventional rotary systems?https://peerj.com/preprints/266412018-03-082018-03-08Gül CelikMurat MadenAhmet SavgatHikmet Orhan
Backround: frequent introduction of new dental instruments or devices into the market has been a concern for dentists worldwide, as the prices of such instruments are generally high, especially in developing countries. In addition, the use of these tools requires new skills and experience. For this reason, while innovations in dentistry are being pursued, it may be advantageous to update the dental instruments that we have been using for years. This study evaluated whether both ProFile and ProTaper files have the potential to reduce the number of files required for shaping curved root canals.
Methods: A total of 45 simulated canals with 40o curvature in clear resin blocks were prepared with conventional rotary systems: ProFile orifice shaping (OS) #3 and final flaring #25/.06, Reciproc R25, and ProTaper shaping file SX and finishing file F2. Pre- and post-instrumentation views were analysed using digital images captured by a camera. Prepared inner and outer walls at 1–10 levels were measured using AutoCAD software. The time required for canal shaping and the frequency of broken instruments were recorded. Standardised pre- and post-instrumentation radiographs were taken to determine changes in working length (WL) and straightening of canal curvature. The presence of blockage or perforation was also evaluated. Data were analysed using the one-way multivariate analysis of variance (ANOVA) and least significant difference test. The level of significance was set at 0.05. The transportation, instrumentation time, change of WL, and instrumentation fractures were evaluated. Data were analysed by ANOVA, Kruskal–Wallis and independent t-test (p<0.05).
Results: Reciproc removed more mass in total and caused less transportation in the middle and coronal third (p<0.001). The transportations performed in the apical third were opposite to the curve. There was no significant difference among the groups in terms of maintaining the original WL. Reciproc was significantly faster (p<0.001). Only one instrument fracture (25/0.06 ProFile) was noted. All groups showed one ledge each.
Discussion: According to this study, both ProFile and ProTaper files have the potential to reduce the number of files required for shaping curved root canals. However, Reciproc, which was produced using a single-file concept, was determined to be more advantageous in terms of time. This study suggests that the conventional rotary technique system might have comparable efficacy to the single-file system for root canal shaping.
Backround: frequent introduction of new dental instruments or devices into the market has been a concern for dentists worldwide, as the prices of such instruments are generally high, especially in developing countries. In addition, the use of these tools requires new skills and experience. For this reason, while innovations in dentistry are being pursued, it may be advantageous to update the dental instruments that we have been using for years. This study evaluated whether both ProFile and ProTaper files have the potential to reduce the number of files required for shaping curved root canals.Methods: A total of 45 simulated canals with 40o curvature in clear resin blocks were prepared with conventional rotary systems: ProFile orifice shaping (OS) #3 and final flaring #25/.06, Reciproc R25, and ProTaper shaping file SX and finishing file F2. Pre- and post-instrumentation views were analysed using digital images captured by a camera. Prepared inner and outer walls at 1–10 levels were measured using AutoCAD software. The time required for canal shaping and the frequency of broken instruments were recorded. Standardised pre- and post-instrumentation radiographs were taken to determine changes in working length (WL) and straightening of canal curvature. The presence of blockage or perforation was also evaluated. Data were analysed using the one-way multivariate analysis of variance (ANOVA) and least significant difference test. The level of significance was set at 0.05. The transportation, instrumentation time, change of WL, and instrumentation fractures were evaluated. Data were analysed by ANOVA, Kruskal–Wallis and independent t-test (p<0.05).Results: Reciproc removed more mass in total and caused less transportation in the middle and coronal third (p<0.001). The transportations performed in the apical third were opposite to the curve. There was no significant difference among the groups in terms of maintaining the original WL. Reciproc was significantly faster (p<0.001). Only one instrument fracture (25/0.06 ProFile) was noted. All groups showed one ledge each.Discussion: According to this study, both ProFile and ProTaper files have the potential to reduce the number of files required for shaping curved root canals. However, Reciproc, which was produced using a single-file concept, was determined to be more advantageous in terms of time. This study suggests that the conventional rotary technique system might have comparable efficacy to the single-file system for root canal shaping. Candida albicans cell wall glycosidases DFG5 and DCW1 are required for biofilm formation and Hog-1 signalinghttps://peerj.com/preprints/265262018-02-152018-02-15Ryan MancusoJennifer ChinniciCharlene TsouSujay BusarajanAbhiram Maddi
Background. Candida albicans is a commensal fungus that inhabits the oral mucosal surface and causes oral and systemic candidiasis. Oral candidiasis most commonly occurs in patients with AIDS, denture wearers and newborn children. Systemic candidiasis occurs mainly in immunocompromised patients and patients admitted to hospitals for prolonged periods. The C. albicans homologous genes, DFG5 and DCW1, encode for two closely related cell wall proteins with putative glycosyltransferase enzyme activity and C-terminal GPI-anchors. Past studies have shown that individual DFG5 and DCW1 mutations are viable but simultaneous deletion of DFG5 and DCW1 in C. albicans results in lethality. However, the exact functions of these cell wall based enzymes, which represent ideal drug targets, are not understood.
Methods. C. albicans DFG5/DCW1 heterologous and conditional double mutant strains, ES1 and ES195 respectively, were assessed for growth and biofilm formation in comparison to wild type and parental strains. Cell wall, osmotic and heat stress susceptibility of the mutant and control strains was assessed using agar spotting assays. Western Blot analysis of mutant strains and control strains was performed to assess Hog-1 phosphorylation status.
Results. Growth in planktonic cultures and biofilm formation was found to be affected in the DFG5/DCW1 double mutants as compared to control strains. The mutant strains were also less resistant to cell wall, osmotic and heat stresses as compared to control strains. Hog-1 phosphorylation was affected in the mutant strains.
Conclusions. These data indicate that Candida albicans DFG5 and DCW1 play critical roles in biofilm formation and Hog-1 signaling pathway.
Background. Candida albicans is a commensal fungus that inhabits the oral mucosal surface and causes oral and systemic candidiasis. Oral candidiasis most commonly occurs in patients with AIDS, denture wearers and newborn children. Systemic candidiasis occurs mainly in immunocompromised patients and patients admitted to hospitals for prolonged periods. The C. albicans homologous genes, DFG5 and DCW1, encode for two closely related cell wall proteins with putative glycosyltransferase enzyme activity and C-terminal GPI-anchors. Past studies have shown that individual DFG5 and DCW1 mutations are viable but simultaneous deletion of DFG5 and DCW1 in C. albicans results in lethality. However, the exact functions of these cell wall based enzymes, which represent ideal drug targets, are not understood.Methods. C. albicans DFG5/DCW1 heterologous and conditional double mutant strains, ES1 and ES195 respectively, were assessed for growth and biofilm formation in comparison to wild type and parental strains. Cell wall, osmotic and heat stress susceptibility of the mutant and control strains was assessed using agar spotting assays. Western Blot analysis of mutant strains and control strains was performed to assess Hog-1 phosphorylation status.Results. Growth in planktonic cultures and biofilm formation was found to be affected in the DFG5/DCW1 double mutants as compared to control strains. The mutant strains were also less resistant to cell wall, osmotic and heat stresses as compared to control strains. Hog-1 phosphorylation was affected in the mutant strains.Conclusions. These data indicate that Candida albicans DFG5 and DCW1 play critical roles in biofilm formation and Hog-1 signaling pathway.An assessment of linear enamel hypoplasia defects in Early Archaic Texan hunter-gatherershttps://peerj.com/preprints/35092018-01-052018-01-05J. Colette BerbesqueKara C Hoover
Digital photographs taken under controlled conditions were used to examine the incidence of linear enamel hypoplasia defects (LEHs) in burials from the Buckeye Knoll archaeological site (41VT98 Victoria county, Texas), which spans the Early to Late Archaic Period (ca. 2500-6500 BP uncorrected radiocarbon). The majority (68 of 74 burials) date to the Texas Early Archaic, including one extremely early burial dated to 8,500 BP. The photogrammetric data collection method also results in an archive for Buckeye Knoll, a significant rare Archaic period collection that has been repatriated and reinterred. We analyzed the incidence and developmental timing of LEHs in permanent canines. Fifty-nine percent of permanent canines (n = 54) had at least one defect. There were no significant differences in LEH frequency between the maxillary and mandibular canines (U = 640.5, n1 = 37, n2 = 43, p = .110). The sample studied (n=92) had an overall mean of 0.93 LEH defect per tooth, with a median of one defect, and a mode of zero defects. Average age at first insult was 3.92 (median = 4.00, range = 2.5 – 5.4) and the mean age of all insults per individual was 4.18 years old (range = 2.5 - 5.67). Age at first insult is consistent with onset of weaning stress—the weaning age range for hunter-gatherer societies is 1- 4.5. Having an earlier age of first insult was associated with having more LEHs (n = 54, rho = -0.381, p = 0.005).
Digital photographs taken under controlled conditions were used to examine the incidence of linear enamel hypoplasia defects (LEHs) in burials from the Buckeye Knoll archaeological site (41VT98 Victoria county, Texas), which spans the Early to Late Archaic Period (ca. 2500-6500 BP uncorrected radiocarbon). The majority (68 of 74 burials) date to the Texas Early Archaic, including one extremely early burial dated to 8,500 BP. The photogrammetric data collection method also results in an archive for Buckeye Knoll, a significant rare Archaic period collection that has been repatriated and reinterred. We analyzed the incidence and developmental timing of LEHs in permanent canines. Fifty-nine percent of permanent canines (n = 54) had at least one defect. There were no significant differences in LEH frequency between the maxillary and mandibular canines (U = 640.5, n1 = 37, n2 = 43, p = .110). The sample studied (n=92) had an overall mean of 0.93 LEH defect per tooth, with a median of one defect, and a mode of zero defects. Average age at first insult was 3.92 (median = 4.00, range = 2.5 – 5.4) and the mean age of all insults per individual was 4.18 years old (range = 2.5 - 5.67). Age at first insult is consistent with onset of weaning stress—the weaning age range for hunter-gatherer societies is 1- 4.5. Having an earlier age of first insult was associated with having more LEHs (n = 54, rho = -0.381, p = 0.005).Effects of shinbuto and ninjinto on prostaglandin E2 production in lipopolysaccharide-treated human gingival fibroblastshttps://peerj.com/preprints/32272017-10-312017-10-31Toshiaki AraNorio Sogawa
Previously, we revealed that several kampo medicines that are used for patients with excess and/or medium patterns [kakkonto (TJ-1), shosaikoto (TJ-9), hangeshashinto (TJ-14), and orento (TJ-120)] reduced prostaglandin (PG)E<2 levels using LPS-treated human gingival fibroblasts (HGFs). Recently, we examined other kampo medicines used for patients with the deficiency pattern [bakumondoto (TJ-29), shinbuto (TJ-30), ninjinto (TJ-32), and hochuekkito (TJ-41)] and the herbs comprising shinbuto and ninjinto using the same experimental model. Shinbuto and ninjinto concentration-dependently reduced LPS-induced PGE2 production by HGFs, whereas hochuekkito weakly reduced and bakumondoto did not reduce PGE2 production. Shinbuto and ninjinto did not alter cyclooxygenase (COX) activity or the expression of molecules involved in the arachidonic acid cascade. Therefore, we next examined which herbs compromising shinbuto and ninjinto reduce LPS-induced PGE2 production. Among these herbs, shokyo (Zingiberis Rhizoma) and kankyo (Zingiberis Processum Rhizoma) strongly and concentration-dependently decreased LPS-induced PGE2 production. However, both shokyo and kankyo increased the expression of cytosolic phospholipase (cPL)A2 but did not affect annexin1 or COX-2 expression. These results suggest that shokyo and kankyo suppress cPLA2 activity. We demonstrated that kampo medicines suppress inflammatory responses in patients with the deficiency pattern, and in those with excess or medium patterns. Moreover, kampo medicines that contain shokyo or kankyo are considered to be effective for the treatment of inflammatory diseases.
Previously, we revealed that several kampo medicines that are used for patients with excess and/or medium patterns [kakkonto (TJ-1), shosaikoto (TJ-9), hangeshashinto (TJ-14), and orento (TJ-120)] reduced prostaglandin (PG)E<2 levels using LPS-treated human gingival fibroblasts (HGFs). Recently, we examined other kampo medicines used for patients with the deficiency pattern [bakumondoto (TJ-29), shinbuto (TJ-30), ninjinto (TJ-32), and hochuekkito (TJ-41)] and the herbs comprising shinbuto and ninjinto using the same experimental model. Shinbuto and ninjinto concentration-dependently reduced LPS-induced PGE2 production by HGFs, whereas hochuekkito weakly reduced and bakumondoto did not reduce PGE2 production. Shinbuto and ninjinto did not alter cyclooxygenase (COX) activity or the expression of molecules involved in the arachidonic acid cascade. Therefore, we next examined which herbs compromising shinbuto and ninjinto reduce LPS-induced PGE2 production. Among these herbs, shokyo (Zingiberis Rhizoma) and kankyo (Zingiberis Processum Rhizoma) strongly and concentration-dependently decreased LPS-induced PGE2 production. However, both shokyo and kankyo increased the expression of cytosolic phospholipase (cPL)A2 but did not affect annexin1 or COX-2 expression. These results suggest that shokyo and kankyo suppress cPLA2 activity. We demonstrated that kampo medicines suppress inflammatory responses in patients with the deficiency pattern, and in those with excess or medium patterns. Moreover, kampo medicines that contain shokyo or kankyo are considered to be effective for the treatment of inflammatory diseases.Evaluation of the maxillary anterior teeth color distribution according to age and gender with Spectrophotometerhttps://peerj.com/preprints/30082017-06-062017-06-06Tahir KaramanEyyüp AltintasBekir EserTuba Talo YildirimFaruk OztekinAlihan Bozoglan
Background: This study intended to determine the colour distribution of the maxillary, central, lateral and canine teeth and to investigate the effect of age and gender on this colour distribution.
Materials and methods : The colour measurements of the maxillary right central, lateral and canine teeth were carried out by the Vita Easyshade V (Vita Zahnfabrik, Bad Sackingen, Germany) spectrophotometer on a total of 202 voluntarily patients including 89 (men) and 113 (women). The age distribution in the study was between 15 and 70 (the average was 31). Grey background colour was used in order to prevent the reflection of the background while performing the colour measurement with the Vita EasyShade V (Vita Zahnfabrik, Bad Sackingen, Germay).
Results: When comparing the L*, a* and b* values of the teeth with the gender; statistically significant difference was not fount between the gender and the L* and b* values (P>0,05) while statistically significant difference was observed between the gender and the a* value (P<0,05).
Conclusions: The tooth colour distribution according to the Vitapan Classical; in the central and lateral teeth it was maximum A2, while it was found to be B3 in the canine teeth. The tooth colour distribution according to the VITA Toothguide 3D-MASTER colour scale; in the central teeth the 2M2 colour was measured most often, in the lateral teeth the 3M2 colour was detected the most often while in the canine teeth the 2M3 colour was measured the most often.
Background: This study intended to determine the colour distribution of the maxillary, central, lateral and canine teeth and to investigate the effect of age and gender on this colour distribution.Materials and methods : The colour measurements of the maxillary right central, lateral and canine teeth were carried out by the Vita Easyshade V (Vita Zahnfabrik, Bad Sackingen, Germany) spectrophotometer on a total of 202 voluntarily patients including 89 (men) and 113 (women). The age distribution in the study was between 15 and 70 (the average was 31). Grey background colour was used in order to prevent the reflection of the background while performing the colour measurement with the Vita EasyShade V (Vita Zahnfabrik, Bad Sackingen, Germay).Results: When comparing the L*, a* and b* values of the teeth with the gender; statistically significant difference was not fount between the gender and the L* and b* values (P>0,05) while statistically significant difference was observed between the gender and the a* value (P<0,05).Conclusions: The tooth colour distribution according to the Vitapan Classical; in the central and lateral teeth it was maximum A2, while it was found to be B3 in the canine teeth. The tooth colour distribution according to the VITA Toothguide 3D-MASTER colour scale; in the central teeth the 2M2 colour was measured most often, in the lateral teeth the 3M2 colour was detected the most often while in the canine teeth the 2M3 colour was measured the most often.Contribution of prosthetic treatment considerations for dental extractions of permanent teethhttps://peerj.com/preprints/21352016-06-162016-06-16Miguel Ángel Fernández-BarreraCarlo Eduardo Medina-SolísJuan Fernando Casanova-RosadoMartha Mendoza-RodríguezMauricio Escoffié-RamírezAlejandro José Casanova-RosadoJosé de Jesús Navarrete-HernándezGerardo Maupomé
Background: Tooth loss is an easily identifiable outcome that summarizes a complex suite of factors in an individual’s history of dental disease and its treatment by dental services over a lifetime. Assessment of overall tooth loss data is essential for evaluating epidemiologically the adequacy of dental care provided at a systems level, as well as for placing in context tooth loss for non-disease causes. For example, when derived from prosthetic treatment planning; the latter may unfortunately lead to some teeth being extracted (pulled) for the sake of better comprehensive clinical results. The objective of the present manuscript was to identify the contribution to overall tooth loss, by extraction of permanent teeth because of prosthetic treatment reasons. Material and Methods: A cross-sectional study included sex, age, total number of extractions performed by subject, sextant (anterior vs. posterior), group of teeth (incisors, canines, premolars and molars), upper or lower arch, and the main reason underlying extraction (extraction for any reason vs. prosthetic treatment), in patients 18 years of age and older seeking care a dental school clinic in Mexico. A multivariate logistic regression model was generated. Results: A total of 749 teeth were extracted in 331 patients; 161 teeth (21.5% of total) were extracted for explicit prosthetic treatment indications. As age increased, the likelihood of having an extraction for prosthetic reasons increased 3% (OR=1.03, p<0.001). Women (OR=1.57, p<0.05) were more likely to be in this situation, and molars (OR=2.70, p<0.001) were most at risk. As the total number of extractions increased, the risk of having an extraction for prosthetic reasons decreased (OR=0.94, p<0.05). Conclusions: A significant amount (21.5%) of the extractions of permanent teeth were performed for prosthetic reasons in this dental school clinical environment; age, sex, type of tooth, and the total number of extractions moderated such pattern.
Background: Tooth loss is an easily identifiable outcome that summarizes a complex suite of factors in an individual’s history of dental disease and its treatment by dental services over a lifetime. Assessment of overall tooth loss data is essential for evaluating epidemiologically the adequacy of dental care provided at a systems level, as well as for placing in context tooth loss for non-disease causes. For example, when derived from prosthetic treatment planning; the latter may unfortunately lead to some teeth being extracted (pulled) for the sake of better comprehensive clinical results. The objective of the present manuscript was to identify the contribution to overall tooth loss, by extraction of permanent teeth because of prosthetic treatment reasons. Material and Methods: A cross-sectional study included sex, age, total number of extractions performed by subject, sextant (anterior vs. posterior), group of teeth (incisors, canines, premolars and molars), upper or lower arch, and the main reason underlying extraction (extraction for any reason vs. prosthetic treatment), in patients 18 years of age and older seeking care a dental school clinic in Mexico. A multivariate logistic regression model was generated. Results: A total of 749 teeth were extracted in 331 patients; 161 teeth (21.5% of total) were extracted for explicit prosthetic treatment indications. As age increased, the likelihood of having an extraction for prosthetic reasons increased 3% (OR=1.03, p<0.001). Women (OR=1.57, p<0.05) were more likely to be in this situation, and molars (OR=2.70, p<0.001) were most at risk. As the total number of extractions increased, the risk of having an extraction for prosthetic reasons decreased (OR=0.94, p<0.05). Conclusions: A significant amount (21.5%) of the extractions of permanent teeth were performed for prosthetic reasons in this dental school clinical environment; age, sex, type of tooth, and the total number of extractions moderated such pattern.Effects of CO2 laser irradiation on matrix-rich biofilm development formation – An in vitro studyhttps://peerj.com/preprints/20842016-05-302016-05-30Bruna Raquel ZancopeVanessa B DaineziMarinês Nobre-dos-SantosSillas Duarte, JrVanessa PardiRamiro M Murata
Background. CO2 laser has been used to morphologically and chemically modify the dental enamel surface as well as to turn it more resistant to demineralization. Despite a variety of experiments demonstrating the inhibitory effect of CO2 laser in reduce enamel demineralization, little is known about the effect of surface irradiated on bacterial growth. Thus, this in vitro study was preformed to evaluate the biofilm formation on enamel previously irradiated with a CO2 laser (λ = 10.6 µM). Methods. For this in vitro study, it was employed 96 specimens of bovine enamel, which were divided into 2 groups (n = 48): 1) Control-non-irradiated surface and 2) Irradiated enamel surface. Biofilms were grown on the enamel specimens by 1, 3 and 5 days under intermittent cariogenic condition in the irradiated and non irradiated surface. In each assessment time, the biofilm were evaluated by dry weigh, counting the number of viable colonies and in fifth day, were evaluated by polysaccharides analysis, quantitative real time PCR as well as by contact angle. In addition, the morphology of biofilms was characterized by fluorescence microscopy and field emission scanning electron microscopy (FESEM). Initially, the assumptions of equal variances and normal distribution of errors were conferred and the results are analyzed statistically by t-test and Mann Whitney test. Results. The mean of log CFU/ml obtained for the 1-day biofilm evaluation showed that there is statistical difference between the experimental groups. When biofilms were exposed to CO2 laser, CFU/mL and CFU/ Dry Weight in 3 day was reduced significantly compared with control group. The difference in the genes expression (gtfB and gbpB) and polysaccharides was not statically significant. Contact angle was increased relative to control when the surface was irradiated with CO2 laser. Similar morphology was also visible with both treatments, however irradiated group revealed evidence of melting and fusion in the specimens. Conclusion. In conclusion CO2 laser irradiation modify the energy surface and disrupt the initial biofilm formation.
Background. CO2 laser has been used to morphologically and chemically modify the dental enamel surface as well as to turn it more resistant to demineralization. Despite a variety of experiments demonstrating the inhibitory effect of CO2 laser in reduce enamel demineralization, little is known about the effect of surface irradiated on bacterial growth. Thus, this in vitro study was preformed to evaluate the biofilm formation on enamel previously irradiated with a CO2 laser (λ = 10.6 µM). Methods. For this in vitro study, it was employed 96 specimens of bovine enamel, which were divided into 2 groups (n = 48): 1) Control-non-irradiated surface and 2) Irradiated enamel surface. Biofilms were grown on the enamel specimens by 1, 3 and 5 days under intermittent cariogenic condition in the irradiated and non irradiated surface. In each assessment time, the biofilm were evaluated by dry weigh, counting the number of viable colonies and in fifth day, were evaluated by polysaccharides analysis, quantitative real time PCR as well as by contact angle. In addition, the morphology of biofilms was characterized by fluorescence microscopy and field emission scanning electron microscopy (FESEM). Initially, the assumptions of equal variances and normal distribution of errors were conferred and the results are analyzed statistically by t-test and Mann Whitney test. Results. The mean of log CFU/ml obtained for the 1-day biofilm evaluation showed that there is statistical difference between the experimental groups. When biofilms were exposed to CO2 laser, CFU/mL and CFU/ Dry Weight in 3 day was reduced significantly compared with control group. The difference in the genes expression (gtfB and gbpB) and polysaccharides was not statically significant. Contact angle was increased relative to control when the surface was irradiated with CO2 laser. Similar morphology was also visible with both treatments, however irradiated group revealed evidence of melting and fusion in the specimens. Conclusion. In conclusion CO2 laser irradiation modify the energy surface and disrupt the initial biofilm formation.Retrospective study of the effectiveness of four different treatments of equine cheek teeth periodontal diseasehttps://peerj.com/preprints/7032016-02-162016-02-16Kirsten JacksonLukas M. WeberMarc Tennant
Reasons for performing the study. Equine cheek teeth periodontal disease is a common, often painful dental condition that may lead to premature tooth loss if left untreated. All cases of periodontal disease in this study were associated with diastemata, with the majority of cases being secondary or senile diastemata. At present limited objective information is available comparing different treatment methods for the condition to assist clinicians in making evidence-based treatment decisions. Objectives. To compare the effectiveness of four commonly used treatments for equine periodontal disease (additional to routine dental treatment and equilibration) to assess their merit in reducing periodontal pocket depth. Study design. Retrospective case series. Methods. Four commonly used equine periodontal treatments were compared: Removing feed material and lavaging the periodontal pocket with dilute chlorhexidine and rinsing the mouth with chlorhexidine based mouthwash (‘Hexarinse’), ‘clean and antiseptic lavage’ (CL); CL plus the addition of metronidazole antibiotics into the periodontal pockets (M); M plus the addition of a polyvinyl siloxane temporary filling over the diastema (PVS); and diastema widening to open the diastema and increase the interdental space between adjacent teeth, then PVS (DW). Periodontal pocket depth measurements were compared before and after treatment at treatment intervals between two and six months. Results. Treatment groups CL, M and PVS showed statistically significant reductions in pocket depth following treatment. Mean pocket depth reduction was greatest in the DW group (and this was the only group with no cases involving an increase in pocket depth), but this was based on a small sample size and was not statistically significant. Additional analysis to compare effectiveness revealed a strong confounding effect of initial pocket depth. After taking this into account, there was some evidence that DW was associated with smaller improvements than the other treatments, however this result was also based on a small sample size, and influenced by a small number of cases with particularly large improvements. Among the other treatments, no statistically significant differences in effectiveness were found. Conclusion. This study has shown that treatment methods CL, M and PVS are associated with statistically significant reductions in pocket depth. Due to the confounding effect of initial pocket depth, no clear differences in effectiveness were found between treatment methods.
Reasons for performing the study. Equine cheek teeth periodontal disease is a common, often painful dental condition that may lead to premature tooth loss if left untreated. All cases of periodontal disease in this study were associated with diastemata, with the majority of cases being secondary or senile diastemata. At present limited objective information is available comparing different treatment methods for the condition to assist clinicians in making evidence-based treatment decisions. Objectives. To compare the effectiveness of four commonly used treatments for equine periodontal disease (additional to routine dental treatment and equilibration) to assess their merit in reducing periodontal pocket depth. Study design. Retrospective case series. Methods. Four commonly used equine periodontal treatments were compared: Removing feed material and lavaging the periodontal pocket with dilute chlorhexidine and rinsing the mouth with chlorhexidine based mouthwash (‘Hexarinse’), ‘clean and antiseptic lavage’ (CL); CL plus the addition of metronidazole antibiotics into the periodontal pockets (M); M plus the addition of a polyvinyl siloxane temporary filling over the diastema (PVS); and diastema widening to open the diastema and increase the interdental space between adjacent teeth, then PVS (DW). Periodontal pocket depth measurements were compared before and after treatment at treatment intervals between two and six months. Results. Treatment groups CL, M and PVS showed statistically significant reductions in pocket depth following treatment. Mean pocket depth reduction was greatest in the DW group (and this was the only group with no cases involving an increase in pocket depth), but this was based on a small sample size and was not statistically significant. Additional analysis to compare effectiveness revealed a strong confounding effect of initial pocket depth. After taking this into account, there was some evidence that DW was associated with smaller improvements than the other treatments, however this result was also based on a small sample size, and influenced by a small number of cases with particularly large improvements. Among the other treatments, no statistically significant differences in effectiveness were found. Conclusion. This study has shown that treatment methods CL, M and PVS are associated with statistically significant reductions in pocket depth. Due to the confounding effect of initial pocket depth, no clear differences in effectiveness were found between treatment methods.