Root discolouration following short-term application of steroid medicaments containing clindamycin, doxycycline or demeclocycline

Current endodontic practice and use of newer technologies in Australia and New Zealand

BACKGROUND

This study investigated endodontic clinical preferences, adoption of newer technologies and information sources among dentists and endodontists.

METHODS

Dental and endodontic society members in Australia and New Zealand were surveyed online regarding their endodontic treatment preferences, armamentarium, information sources and continuing professional education (CPE) attendance.

RESULTS

Complete responses were received from 71 endodontic specialists or postgraduates (Group E) and 139 general dentists (Group D). Most of Group E used dental operating microscopes (95.8%), endodontic cone-beam computed tomography (CBCT; 98.6%) and calcium silicate-based materials (CSBMs; 97.2%), significantly more (P < 0.001) than Group D (86.3% used loupes, <32% used CBCT for endodontics or CSBMs). Most respondents used dental dam always for endodontics (94.3%), electronic apex locators (EAL; 81.0%) and engine-driven nickel-titanium (NiTi) instruments (91.4%); Group E had more experience with engine-driven NiTi (P < 0.001). Endodontic CPE attendance was highest at dental association programs (P < 0.001) while hands-on NiTi training attendance was highest via commercial companies (P < 0.05). Online information sources were commonly used (38.8% of Group D, 59.2% of Group E).

CONCLUSION

Dental dam, EAL and engine-driven NiTi were almost universally used. The endodontic group reported high adoption of newer endodontic technologies. Endodontic CPE and information sources should be further surveyed as online engagement evolves. © 2023 Australian Dental Association.

Does luminosity and smear layer influence 810 nm laser energy transmission through human dentine?

PURPOSE

The aim of this study was to evaluate the influence of luminosity values and smear layer on transmission characteristics of 810 nm near infrared laser energy through dentine, using extracted human teeth.

METHODS

A total of 200 teeth treated with endodontic medicaments to cause discolouration (Ledermix, Doxypaste or Odontopaste) were selected, to give a range of values for tooth shade (luminosity values). Sectioned teeth had smear layer created or removed. Near-infrared laser energy transmission was assessed using an 810 nm diode laser (90 mW, CW mode) with the tip placed at 2 mm and 4 mm from the external root surface, and a laser power metre.

RESULTS

Both tooth shade and smear layer had independent attenuating effects. Transmission of laser energy was significantly lower in teeth with darker shades. There was a strong positive correlation between relative luminosity (lighter tooth colour) and transmitted laser power (r = 0.9271 for the Spearman rank correlation, P = 0.0022). When a smear layer was present, this significantly reduced the transmission of laser energy through the sample, compared to when no smear layer was present.

CONCLUSION

The results of this laboratory study highlight the attenuating influence of a darker tooth shade and the presence of smear layer on the transmission of 810 nm light when directed onto the surface of human dentine. Such effects may be relevant to photo biomodulation, Photodynamic Therapy and other dental laser treatments.

Laser-fluorescence assessment of sodium hypochlorite quenching reversal agents on human dentine

BACKGROUND

Laser-fluorescence diagnostic technology for real-time clinical assessment of residual bacteria could help assist in determining the endpoints for root canal debridement. Sodium hypochlorite (NaOCl) can however quench fluorescence and lead to false low reading. This study aims to evaluate various antioxidant for their ability to recover quenched fluorescence in dentine treated with NaOCl.

METHODS

Human dentine fluorescence was measured using 655 nm laser at baseline and again after a 2 min application of 4% NaOCl. The putative recovery agents were then applied, and the fluorescence measured after 5, 10, 20, 30 and 60 min. Recovery from quenching was also assessed using laser confocal scanning microscopy (CLSM) with a bound tetracycline fluorophore using 488 nm excitation.

RESULTS

A 5 min application of vitamin E oil or buffered 2% lignocaine solution (1:80,000 adrenaline) was effective in regaining quenched fluorescence within the following 5 mins. Distilled water, sodium thiosulfate, unbuffered 2% lignocaine with 1:80000 adrenaline and phosphate buffered saline were less effective, and of equal performance. Ascorbic acid and butylated hydroxyanisole were not effective and had deleterious effects on the levels of dentine fluorescence. CLSM provided confirmation of recovery from quenched fluorescence using vitamin E oil.

CONCLUSION

Based on these findings, reversal agents should be employed when assessing the fluorescence of dentine that has been exposed to NaOCl or other quenching agents.

A critical analysis of research methods and experimental models to study tooth discolouration from endodontic materials

As a range of materials used in endodontics may cause tooth discolouration, exploration of factors responsible for the darkening of the tooth crown or root is warranted. This narrative review paper discusses the range of technical factors that apply in laboratory studies that assess endodontic discolouration. As an example of how these factors operate, particular examples relating to discolouration caused by endodontic medicaments containing tetracycline antibiotics are used. Following the PRILE 2021 guidelines approach, a summary of key variables to be addressed in the methodology for laboratory studies is presented, to inform future work.

Determination of crown discoloration and fluorescence induced by different medications used in regenerative endodontic procedures: An ex vivo study

Background

Crown discoloration is an undesirable side effect of the use of triple antibiotic paste (TAP) in regenerative endodontic procedures (REPs). The aim of this ex vivo study was to assess the potential for tooth discoloration and induction of fluorescence associated with the use of TAP containing either doxycycline (DOX) or clindamycin (CLIN), and of calcium hydroxide (Ca(OH)2), by spectrophotometric analysis and confocal laser scanning microscopy (CLSM).

Material and Methods

A total of forty single-rooted human teeth extracted by therapeutic indication were used. The root canals were enlarged using the step-back technique up to a K #80 file and were randomly divided into four experimental groups (10 specimens each): i)Ca(OH)2 group, ii)TAP with DOX group, iii) TAP with CLIN group, iv) Control group (no treatment). To quantify the change of color of the different groups of teeth included, the Vita Easyshade advance 4.0 spectrophotometer was used. CLSM was used to determine fluorescence.

Results

After 28 days of action inside the root canal, no extreme discoloration was visible, to the naked eye, in any of the teeth included in the study. Under the conditions of this ex vivo study, TAP with DOX induced the highest crown discoloration among the medicaments tested. In contrast, Ca(OH)2 and TAP with CLIN did not induce crown discoloration after 28 days. The TAP with DOX group presented the highest fluorescence measurements.

Conclusions

Considering the discoloration potential and fluorescence changes in TAP with DOX or other tetracyclines, and the cytotoxic effect of TAPs, we recommend the use of Ca(OH)2 for REPs.

Key words:Discoloration, doxycycline, clinadamycin, calcium hydroxide, endodontics.

Effectiveness of D,L-2-hydroxyisocaproic acid (HICA) and alpha-mangostin against endodontopathogenic microorganisms in a multispecies bacterial-fungal biofilm in an ex vivo tooth model

AIM

To develop a defined multispecies root canal biofilm model ex vivo, and to perform viable compositional analysis following D,L-2-hydroxyisocaproic acid (HICA), alpha-mangostin, Calcicur^® , and Odontopaste^® exposure.

METHODOLOGY

Time-kill assays were conducted in vitro using HICA, alpha-mangostin, Calcicur^® , Odontopaste^® , and saline solution on the planktonic cultures of C. albicans, E. faecalis, L. rhamnosus, and S. gordonii. Human root dentine blocks were prepared (n = 100) ex vivo, and multispecies suspensions containing each of 1.5 × 10⁸  CFU/mL C. albicans, E. faecalis, L. rhamnosus, and S. gordonii in brain heart infusion (BHI) were incubated within the root canals for 21 days. Canals (n = 20/group) were then exposed to medicaments for 7 days. Samples taken from the inner (first 0.1 mm) and deeper (second 0.1 mm) dentine by drilling with Ash Steel Burs No. 5 and No. 6, and residual roots were cultured in broth for 24 h. Cell growth was detected by spectrophotometry and confirmed by culture on agar. The other set of inner dentine, deeper dentine, and residual root samples were sonicated, and then exposed with 50 μM PMA before DNA was extracted using the QIAamp DNA mini kit. Real-time quantitative PCR was performed to determine the biofilm composition as well as the number of live and total cells remaining in the biofilm following each treatment. The OD data were analysed with Kruskal-Wallis and Friedman with Wilcoxon signed-rank test between and within groups, respectively, agar culture and qPCR data with Pearson chi-square with Mann-Whitney and Cochran with McNemar tests, respectively (p < .0001).

RESULTS

Time-kill assays revealed that HICA and Calcicur^® killed all planktonic organisms within 24 h, whilst alpha-mangostin killed the organisms within 72 h. However, Odontopaste^® was a slow-killing agent: 10 cells of planktonic organisms survived after exposure to the agent for 7 days. The ex vivo tooth model demonstrated that HICA and alpha-mangostin significantly inhibited the cell growth in all sampling depths (p < .0001). All species-specific data revealed the effectiveness of each medicament on the biofilm composition.

CONCLUSIONS

D,L-2-hydroxyisocaproic acid and alpha-mangostin had antimicrobial activity against multispecies bacterial-fungal biofilms.

Effect of tetracyclines on pulpal and periodontal healing after tooth replantation: a systematic review of human and animal studies

Background

Pulpal and periodontal healing are two main concerns of delayed replantation of avulsed teeth. The objective of this review was to evaluate the effectiveness of topical and systemic application of tetracyclines on pulpal and periodontal healing after tooth replantation.

Methods

A comprehensive electronic search was conducted in six databases. This systematic review was carried out according to Cochrane Handbook and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Results

After exclusion of 246 irrelevant papers, 14 animal studies and one human study were included in this review. The human study showed that avulsed permanent teeth treated with doxycycline did not show a better clinical outcome for pulp and periodontal healing compared with treatment with normal saline. As for animal studies, significant more pulpal healing was observed in immature teeth treated with topical doxycycline in two researches, while another one study showed that there is no difference between teeth treated with normal saline and teeth treated with doxycycline. Systemic doxycycline exerted no significant effect on pulpal revascularization illustrated by one research. Only one out of four articles illustrated the positive effect of systemic tetracyclines on periodontal healing. One paper reported that intracanal application of demeclocycline promoted favorable periodontal healing. Two articles showed topical doxycycline contributed to favorable periodontal healing, while five studies showed no significant effect of topical tetracyclines on periodontal healing.

Conclusions

As a result of data heterogeneity and limitations of the studies, the effect of topical or systemic application of tetracyclines on pulpal and periodontal healing is inconclusive. More studies are required to get more clinically significant conclusions.

Spectrophotometric insights: calcium hydroxide influences tooth discolorations induced by short-term application of antibiotic/corticosteroid pastes

OBJECTIVES

This in vitro study aimed to assess the influence of a calcium hydroxide dressing regarding the relative color change (ΔE) of enamel-dentin specimens previously exposed to antibiotic/corticosteroid pastes.

MATERIALS AND METHODS

Eighty bovine enamel-dentin specimens with a cylindrical central cavity were randomly allocated to four groups: NEG (empty), POS (blood), LED (Ledermix), and ODO (Odontopaste) (n = 20 each). The materials were applied and sealed with self-adhesive resin luting material. After 3 weeks, the materials were removed and a calcium hydroxide (Ca(OH)₂) dressing was placed in all cavities. After a further 3-week storage period, the cavities were restored with resin-based composite. Spectrophotometric color measurements were taken over 6 months, and ΔE values were calculated. A Tukey's multiple comparison test was performed to assess significant differences within the treatment groups (p < 0.05).

RESULTS

Tooth discolorations were present after 3 weeks in LED (ΔE 29.14 ± 6.55) and POS (ΔE 18.05 ± 7.03); NEG and ODO remained color stable (ΔE 3.2 ± 1.36 and ΔE 2.3 ± 1.16). The 3-week Ca(OH)₂ dressing decreased discolorations of POS (ΔE 15.93 ± 6.63; p = 0.37), whereas LED showed a further significant increase (ΔE 39.55; p < 0.0001). Between the end of the Ca(OH)₂ dressing and the final restoration no significant color changes were observed in any group (p > 0.9).

CONCLUSIONS

Discolorations induced by LED progressed during the Ca(OH)₂ dressing despite careful removal of all residues.

CLINICAL RELEVANCE

Calcium hydroxide might negatively affect the discoloring potential of Ledermix. This highlights the need for direct intracanal application methods of Ledermix ensuring a material-free access cavity or alternative antibiotic/corticosteroid pastes such as Odontopaste should be used.

Mechanisms of Staining with Demeclocycline and Doxycycline Root Canal Medicaments

Tetracyclines are a unique class of antibiotics which also have additional effects including anti-inflammatory, anti-resorptive and substantive within the root canal. There has been a long-held view that tetracycline medicaments discolour teeth and should be avoided. The evidence base around this topic was explored, including a review of the methodology used in laboratory studies. A search of PubMed, Medline and Scopus databases was conducted to identify studies of demeclocycline and doxycycline medicaments used in root canal therapy. An analysis of the methodology used in these studies was performed to determine if these replicate current clinical practice. The related literature on mechanisms of tetracycline stability and the effects of light, oxidation, moisture and chemical interactions was examined. Studies investigating the effects of Ledermix paste on segments of bovine dentine and avulsed or reimplanted teeth as well as combinations with other antibiotics were excluded from this review. Even though demeclocycline medicament pastes were introduced in 1962, the first laboratory studies of discolouration were not done until 2000. All later studies followed a similar approach, which included exposure to sodium hypochlorite for up to 30 minutes and storage in moist conditions with 100% humidity. Staining during dark storage and enhanced staining on exposure to light were reported, indicating multiple pathways of degradation of demeclocycline and its reaction products. Light, moisture and oxidation are the key factors which drive discolouration from demeclocycline. Clinical issues from tooth staining can be prevented by removal of medicament pastes from the access cavity, and placement of a sound interim restoration. Use of a doxycycline paste obviates concerns of staining. Laboratory assessments of the potential for staining should replicate in vivo conditions.

Dispersion of near-infrared laser energy through radicular dentine when using plain or conical tips

The aim of this study was to investigate the influence of tip design on patterns of laser energy dispersion through the dentine of tooth roots when using near-infrared diode lasers. Diode laser emissions of 810 or 940 nm were used in combination with optical fiber tips with either conventional plain ends or conical ends, to irradiate tooth roots of oval or round cross-sectional shapes. The lasers were operated in continuous wave mode at 0.5 W for 5 s with the distal end of the fiber tip placed in the apical or coronal third of the root canal at preset positions. Laser light exiting through the roots and apical foramen was imaged, and the extent of lateral spread calculated. There was a significant difference in infrared light exiting the root canal apex between plain and conical fiber tips for both laser wavelengths, with more forward transmission of laser energy through the apex for plain tips. For both laser wavelengths, there were no significant differences in emission patterns when the variable of canal shape was used and all other variables were kept the same (plain vs conical tip, tip position). To ensure optimal treatment effect and to prevent the risks of inadvertent laser effects on the adjacent periapical tissues, it is important to have a good understanding of laser transmission characteristics of the root canal and root dentine. Importantly, it is also essential to understand transmission characteristics of plain and conical fibers tips.

Effect of Photo-Fenton Bleaching on Tetracycline-stained Dentin in vitro

Aim

Tetracycline-stained tooth structure is difficult to bleach using nightguard tray methods. The possible benefits of in-office light-accelerated bleaching systems based on the photo-Fenton reaction are of interest as possible adjunctive treatments. This study was a proof of concept for possible benefits of this approach, using dentine slabs from human tooth roots stained in a reproducible manner with the tetracycline antibiotic demeclocycline hydrochloride.

Materials and methods

Color changes overtime in tetracycline stained roots from single rooted teeth treated using gel (Zoom! WhiteSpeed®) alone, blue LED light alone, or gel plus light in combination were tracked using standardized digital photography. Controls received no treatment. Changes in color channel data were tracked overtime, for each treatment group (N = 20 per group).

Results

Dentin was lighter after bleaching, with significant improvements in the dentin color for the blue channel (yellow shade) followed by the green channel and luminosity. The greatest changes occurred with gel activated by light (p < 0.0001), which was superior to effects seen with gel alone. Use of the light alone did not significantly alter shade.

Conclusion

This proof of concept study demonstrates that bleaching using the photo-Fenton chemistry is capable of lightening tetracycline-stained dentine. Further investigation of the use of this method for treating tetracycline-stained teeth in clinical settings appears warranted.

Clinical significance

Because tetracycline staining may respond to bleaching treatments based on the photo-Fenton reaction, systems, such as Zoom! WhiteSpeed, may have benefits as adjuncts to home bleaching for patients with tetracycline-staining.

How to cite this article

Bennett ZY, Walsh LJ. Effect of Photo- Fenton Bleaching on Tetracycline-stained Dentin in vitro. J Contemp Dent Pract 2015;16(2):126-129.

Efficacy of LED versus KTP laser activation of photodynamic bleaching of tetracycline-stained dentine

In some well-established laser applications where large spot sizes are used, an array of high-intensity light emitting diodes (LED) emitting at similar wavelength could potentially replace the laser. This situation applies for the photodynamic bleaching of stains in teeth. This study compared the relative efficacy of an array of visible green LED (535 nm ± 15 nm) with a KTP laser in photodynamic bleaching of tetracycline-stained dentine in human tooth roots. After establishing consistent staining in 96 roots using a validated method, the roots were sectioned into 2-3-mm thick horizontal slices that were treated with gels containing rhodamine B (Smartbleach® or Smartbleach® 3LT). Colour changes were tracked up to 1 month after treatment. While both systems were effective in bleaching the tetracycline-stained dentine, KTP laser activation gave greater bleaching efficacy than LED activation, enhancing the action of the gel. Use of the KTP laser would be preferable over an LED system when confronted with tetracycline staining. Use of this photodynamic bleaching method offers valuable means to reduce the severity of tetracycline staining.

Factors affecting the rate of oxidation and resultant discolouration of tetracyclines contained in endodontic medicaments and irrigants

AIM

To determine the effect of pH, oxygen levels and ions on tetracycline oxidation and resultant discolouration.

METHODOLOGY

Solutions of demeclocycline hydrochloride or doxycycline hyclate were prepared and exposed to different pH conditions, pure oxygen or carbon dioxide, ascorbic acid or various ions (from calcium chloride, calcium nitrate, strontium chloride, magnesium chloride, zinc chloride, and bismuth nitrate). Subsequently, they were exposed to intense visible blue light (470 ± 15 nm) for 24 h. Colour change was monitored using standardized digital photography. Parametric statistical analysis employing the Wilcoxon matched-pairs signed-rank test was performed to compare the mean change in different colour channels, assessing the discolouration effect of the modified conditions.

RESULTS

An acidic pH reduced discolouration, whilst alkaline pH increased it. A higher oxygen tension resulted in more discolouration, as did the presence of calcium, strontium, and bismuth ions, all of which bind to tetracyclines. Conversely, zinc and magnesium ions had a mild photoprotective effect. Ascorbic acid, an anti-oxidant, reduced the level of discolouration.

CONCLUSIONS

The tendency of these tetracyclines to undergo photo-oxidation is increased by common variables present in the clinical environment. There are potential benefits from using photoprotectors and anti-oxidants in these materials, to reduce the possibility of discolouration.

Discoloration of roots caused by residual endodontic intracanal medicaments

AIMS

This study examined the extent to which intervisit corticosteroid-based antibiotic pastes (CAP) medicaments contribute to staining of tooth structure after attempted removal by irrigation techniques.

METHODS

A total of 140 roots were prepared and the canals were filled with Ledermix paste (demeclocycline), Odontopaste (clindamycin), and Doxypaste (doxycycline). The pastes were removed after 2 or 4 weeks of storage in the dark using EDTA and NaOCl with either a 27-gauge-slotted needle or an EndoActivator (Dentsply). The roots were then exposed to an intense light source for 30 minutes each week and photographed after a further 1, 3, or 6 months. Digital images were standardized and data for changes in luminosity were analysed using repeated measures ANOVA and a post hoc test.

RESULTS

Removal of the medicament did not prevent later discolouration. There was no significant difference between the paste removal methods. Ledermix paste caused the greatest darkening compared to the untreated controls, for both application periods and both methods of removal. Doxypaste and Odontopaste caused less darkening than Ledermix.

CONCLUSION

Medicaments that stain teeth may continue to discolour teeth despite best attempts to remove them. This study stresses the importance of material selection and minimising contact of Ledermix within the coronal aspects of teeth.

Effectiveness of different intracanal irrigation techniques in removing intracanal paste medicaments

This study aimed to compare the effectiveness of different intracanal irrigation techniques in removing intracanal medicaments prior to obturation. A total of 168 single roots were prepared with ProTaper® rotary files and medicament pastes applied (Ledermix®, Odontopaste®, Doxypaste and Pulpdent®), left in for 2 weeks, then removed using filing followed by one of four methods: irrigation with an open-ended notched irrigation needle (Appli-Vac) either at the working length or 5 mm from the canal orifice, or the Max-I-probe or EndoActivator® at the working length. Following the removal of medicaments, the roots were split into two and the internal surfaces photographed, for digital image analysis of the overall percentage of residual medicament. With the exception of canals irrigated 5 mm apical to the root canal orifice, all four irrigation techniques achieved an average of 95% for removal of Ledermix®, Odontopaste® and Doxypaste. Calcium hydroxide paste was the most difficult medicament to remove, with no difference between irrigation techniques. Up to 27% of the Pulpdent® material remained after irrigation. No irrigation technique could completely remove all traces of medicaments. The position of the irrigational needle and the type of medicament used are key factors, which influence the effectiveness of irrigation in removing medicaments.