{"id":{"repo_id":"iupui","oai_identifier":"oai:scholarworks.indianapolis.iu.edu:1805/56848"},"canonical_url":"https://search.dev.ndltd.org/etd/iupui/oai:scholarworks.indianapolis.iu.edu:1805/56848","repository":{"repo_id":"iupui","name":"IUPUI","base_url":"https://scholarworks.indianapolis.iu.edu/server/oai/request"},"display":{"title":"In Vitro Evaluation of the Biolase ER,CR:YSGG Side-Firing Tip For Bacterial Biofilm Reduction and Smear Layer Removal in Root-End Cavity Preparation","abstract":"Objective Persistent endodontic infections are frequently associated with residual bacterial biofilm and smear layer that may remain after conventional chemomechanical debridement and ultrasonic root-end preparation, contributing to post-treatment apical periodontitis and compromising root-end surface cleanliness. The objective of this in vitro study was to evaluate the antimicrobial efficacy and smear layer removal capacity of a Biolase Waterlase iPlus Er,Cr:YSGG laser equipped with a side-firing tip on Enterococcus faecalis biofilm-contaminated retroprepared root-end surfaces. Methods Twenty-five extracted permanent maxillary central incisors were prepared, obturated, apically resected by 3 mm, and retroprepared to a standardized 3 mm depth. Specimens were randomly allocated into three groups: laser-treated experimental specimens inoculated with E. faecalis biofilm (n = 10), inoculated untreated negative controls (n = 10), and uninoculated controls (n = 5). Experimental and negative control specimens were inoculated with E. faecalis for 7 days. The experimental group received Er,Cr:YSGG irradiation using a side-firing tip in implant decontamination mode at 1.5 W, 30 Hz, 40% air, and 50% water for two 1-minute cycles. Residual viable bacteria were sampled, serially diluted, plated, incubated, and quantified as colony forming units per milliliter. Log-transformed data were analyzed using one-way ANOVA, and representative specimens were examined by scanning electron microscopy. Results The inoculated untreated control group demonstrated the highest bacterial burden, with a geometric mean of 198,898 CFU/mL. The laser-treated group showed a significantly lower geometric mean of 53,393 CFU/mL, representing a 3.7-fold reduction compared with the negative control group (p = 0.009). No statistically significant difference was detected between the laser-treated and uninoculated control groups (p = 0.479). SEM observations supported the quantitative findings, demonstrating reduced biofilm and smear layer coverage with exposed dentinal tubules on the laser-treated surface. Conclusion Within the limitations of this in vitro model, Er,Cr:YSGG laser irradiation delivered through a side-firing tip significantly reduced recoverable E. faecalis biofilm on retroprepared root-end surfaces. Qualitative SEM findings demonstrated less residual biofilm and smear layer coverage on the laser-treated surface compared with the untreated control, supporting the microbiologic results. These findings suggest that side-firing Er,Cr:YSGG laser irradiation may represent a promising adjunct for root-end decontamination in endodontic microsurgery.","abstract_html":"Objective Persistent endodontic infections are frequently associated with residual bacterial biofilm and smear layer that may remain after conventional chemomechanical debridement and ultrasonic root-end preparation, contributing to post-treatment apical periodontitis and compromising root-end surface cleanliness. The objective of this in vitro study was to evaluate the antimicrobial efficacy and smear layer removal capacity of a Biolase Waterlase iPlus Er,Cr:YSGG laser equipped with a side-firing tip on Enterococcus faecalis biofilm-contaminated retroprepared root-end surfaces. Methods Twenty-five extracted permanent maxillary central incisors were prepared, obturated, apically resected by 3 mm, and retroprepared to a standardized 3 mm depth. Specimens were randomly allocated into three groups: laser-treated experimental specimens inoculated with E. faecalis biofilm (n = 10), inoculated untreated negative controls (n = 10), and uninoculated controls (n = 5). Experimental and negative control specimens were inoculated with E. faecalis for 7 days. The experimental group received Er,Cr:YSGG irradiation using a side-firing tip in implant decontamination mode at 1.5 W, 30 Hz, 40% air, and 50% water for two 1-minute cycles. Residual viable bacteria were sampled, serially diluted, plated, incubated, and quantified as colony forming units per milliliter. Log-transformed data were analyzed using one-way ANOVA, and representative specimens were examined by scanning electron microscopy. Results The inoculated untreated control group demonstrated the highest bacterial burden, with a geometric mean of 198,898 CFU/mL. The laser-treated group showed a significantly lower geometric mean of 53,393 CFU/mL, representing a 3.7-fold reduction compared with the negative control group (p = 0.009). No statistically significant difference was detected between the laser-treated and uninoculated control groups (p = 0.479). SEM observations supported the quantitative findings, demonstrating reduced biofilm and smear layer coverage with exposed dentinal tubules on the laser-treated surface. Conclusion Within the limitations of this in vitro model, Er,Cr:YSGG laser irradiation delivered through a side-firing tip significantly reduced recoverable E. faecalis biofilm on retroprepared root-end surfaces. Qualitative SEM findings demonstrated less residual biofilm and smear layer coverage on the laser-treated surface compared with the untreated control, supporting the microbiologic results. These findings suggest that side-firing Er,Cr:YSGG laser irradiation may represent a promising adjunct for root-end decontamination in endodontic microsurgery.","abstract_has_math":false,"creators":["Morris, Logan Samuel"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Karunanayake, Glen"],"committee_chairs":[],"committee_members":[],"year":2026,"date_issued":"2026-06","date_published":"2026-06","updated_at":"2026-07-24T02:41:19Z","subjects":["Endodontic microsurgery","Er,Cr:YSGG laser","side-firing tip","Enterococcus faecalis","root-end disinfection","biofilm","scanning electron microscopy"],"languages":["en_US"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/1805/56848","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Karunanayake, Glen"]},{"key":"dc:contributor.other","label":"Dc Contributor Other","values":["Gregory, Richard","Movila, Alexandru"]},{"key":"dc:creator","label":"Author","values":["Morris, Logan Samuel"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2026-06-15T12:27:21Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2026-06-15T12:27:21Z"]},{"key":"dc:date.issued","label":"Date","values":["2026-06"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Endodontic microsurgery","Er,Cr:YSGG laser","side-firing tip","Enterococcus faecalis","root-end disinfection","biofilm","scanning electron microscopy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/1805/56848"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Indiana University Indianapolis (IUI)"]},{"key":"dc:description.abstract","label":"Abstract","values":["Objective Persistent endodontic infections are frequently associated with residual bacterial biofilm and smear layer that may remain after conventional chemomechanical debridement and ultrasonic root-end preparation, contributing to post-treatment apical periodontitis and compromising root-end surface cleanliness. The objective of this in vitro study was to evaluate the antimicrobial efficacy and smear layer removal capacity of a Biolase Waterlase iPlus Er,Cr:YSGG laser equipped with a side-firing tip on Enterococcus faecalis biofilm-contaminated retroprepared root-end surfaces. Methods Twenty-five extracted permanent maxillary central incisors were prepared, obturated, apically resected by 3 mm, and retroprepared to a standardized 3 mm depth. Specimens were randomly allocated into three groups: laser-treated experimental specimens inoculated with E. faecalis biofilm (n = 10), inoculated untreated negative controls (n = 10), and uninoculated controls (n = 5). Experimental and negative control specimens were inoculated with E. faecalis for 7 days. The experimental group received Er,Cr:YSGG irradiation using a side-firing tip in implant decontamination mode at 1.5 W, 30 Hz, 40% air, and 50% water for two 1-minute cycles. Residual viable bacteria were sampled, serially diluted, plated, incubated, and quantified as colony forming units per milliliter. Log-transformed data were analyzed using one-way ANOVA, and representative specimens were examined by scanning electron microscopy. Results The inoculated untreated control group demonstrated the highest bacterial burden, with a geometric mean of 198,898 CFU/mL. The laser-treated group showed a significantly lower geometric mean of 53,393 CFU/mL, representing a 3.7-fold reduction compared with the negative control group (p = 0.009). No statistically significant difference was detected between the laser-treated and uninoculated control groups (p = 0.479). SEM observations supported the quantitative findings, demonstrating reduced biofilm and smear layer coverage with exposed dentinal tubules on the laser-treated surface. Conclusion Within the limitations of this in vitro model, Er,Cr:YSGG laser irradiation delivered through a side-firing tip significantly reduced recoverable E. faecalis biofilm on retroprepared root-end surfaces. Qualitative SEM findings demonstrated less residual biofilm and smear layer coverage on the laser-treated surface compared with the untreated control, supporting the microbiologic results. These findings suggest that side-firing Er,Cr:YSGG laser irradiation may represent a promising adjunct for root-end decontamination in endodontic microsurgery."]},{"key":"dc:title","label":"Title","values":["In Vitro Evaluation of the Biolase ER,CR:YSGG Side-Firing Tip For Bacterial Biofilm Reduction and Smear Layer Removal in Root-End Cavity Preparation"]}]}],"canonical_facts":{"dc:contributor.advisor":["Karunanayake, Glen"],"dc:contributor.other":["Gregory, Richard","Movila, Alexandru"],"dc:creator":["Morris, Logan Samuel"],"dc:date.accessioned":["2026-06-15T12:27:21Z"],"dc:date.available":["2026-06-15T12:27:21Z"],"dc:date.issued":["2026-06"],"dc:description":["Indiana University Indianapolis (IUI)"],"dc:description.abstract":["Objective Persistent endodontic infections are frequently associated with residual bacterial biofilm and smear layer that may remain after conventional chemomechanical debridement and ultrasonic root-end preparation, contributing to post-treatment apical periodontitis and compromising root-end surface cleanliness. The objective of this in vitro study was to evaluate the antimicrobial efficacy and smear layer removal capacity of a Biolase Waterlase iPlus Er,Cr:YSGG laser equipped with a side-firing tip on Enterococcus faecalis biofilm-contaminated retroprepared root-end surfaces. Methods Twenty-five extracted permanent maxillary central incisors were prepared, obturated, apically resected by 3 mm, and retroprepared to a standardized 3 mm depth. Specimens were randomly allocated into three groups: laser-treated experimental specimens inoculated with E. faecalis biofilm (n = 10), inoculated untreated negative controls (n = 10), and uninoculated controls (n = 5). Experimental and negative control specimens were inoculated with E. faecalis for 7 days. The experimental group received Er,Cr:YSGG irradiation using a side-firing tip in implant decontamination mode at 1.5 W, 30 Hz, 40% air, and 50% water for two 1-minute cycles. Residual viable bacteria were sampled, serially diluted, plated, incubated, and quantified as colony forming units per milliliter. Log-transformed data were analyzed using one-way ANOVA, and representative specimens were examined by scanning electron microscopy. Results The inoculated untreated control group demonstrated the highest bacterial burden, with a geometric mean of 198,898 CFU/mL. The laser-treated group showed a significantly lower geometric mean of 53,393 CFU/mL, representing a 3.7-fold reduction compared with the negative control group (p = 0.009). No statistically significant difference was detected between the laser-treated and uninoculated control groups (p = 0.479). SEM observations supported the quantitative findings, demonstrating reduced biofilm and smear layer coverage with exposed dentinal tubules on the laser-treated surface. Conclusion Within the limitations of this in vitro model, Er,Cr:YSGG laser irradiation delivered through a side-firing tip significantly reduced recoverable E. faecalis biofilm on retroprepared root-end surfaces. Qualitative SEM findings demonstrated less residual biofilm and smear layer coverage on the laser-treated surface compared with the untreated control, supporting the microbiologic results. These findings suggest that side-firing Er,Cr:YSGG laser irradiation may represent a promising adjunct for root-end decontamination in endodontic microsurgery."],"dc:identifier.uri":["https://hdl.handle.net/1805/56848"],"dc:language.iso":["en_US"],"dc:subject":["Endodontic microsurgery","Er,Cr:YSGG laser","side-firing tip","Enterococcus faecalis","root-end disinfection","biofilm","scanning electron microscopy"],"dc:title":["In Vitro Evaluation of the Biolase ER,CR:YSGG Side-Firing Tip For Bacterial Biofilm Reduction and Smear Layer Removal in Root-End Cavity Preparation"],"dc:type":["Thesis"]},"updated_at":"2026-07-24T02:41:19Z"}