Identification of esters in carious dentine Staining and chemo-mechanical excavation

Dental caries is clinically seen as a yellowish-brown discoloration that can be explained by the reactions between proteins and sugars resulting in Maillard products. However, the discoloration of carious dentine is an imprecise indicator of whether or not the dentine is caries free. Other processes might act in concert with the Maillard reactions. This thesis describes how special functional groups formed in the carious process can be used in connection with dyes that selectively stain the carious tissue in order to avoid over excavation. The initial study aimed to analyse unique functional groups in sound and carious dentine and their presumed reaction with hydrazine derivative using Fourier Transform Infrared Spectroscopy (FTIR) and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). The second and third studies focused on the possible formation of covalent bonds between carious dentine and 15N2-hydrazine, 15N2-labelled Lucifer yellow, and stains carrying a hydrazine derivative respectively, using ToF-SIMS, solid-state NMR spectroscopy (13C and 15N) and light-microscopic observations. The latter aimed to evaluate the type of binding, electrostatic or covalent, to carious dentine. In a systematic review with an adjacent meta-analysis, the ability of a chemically based product in clinical caries excavation was evaluated by comparing the efficacy of chemo-mechanical excavation with that of traditional rotating instruments. The results revealed ester groups unique to the carious dentine, with a higher occurrence in the inner layer of carious dentine, which, after reaction with hydrazine derivative, form covalent bonds not seen in sound dentine. This is a selective binding in comparison with dyes with only an electrostatic binding capacity. The systematic review found that the chemo-mechanical excavation technique is as efficient as burs, albeit with a longer treatment time but with enhanced patient comfort. It is concluded that ester functional groups unique to carious dentine can be specifically stained with dyes carrying a hydrazine group, thereby acting selectively in distinguishing between sound and carious dentine. As a result, using a more precise indicator will support the identification of the end-point during clinical caries excavation

Treatment of peri-implantitis : clinical outcome of chloramine as an adjunctive to non-surgical therapy, a randomized clinical trial

PurposeTo evaluate the adjunctive clinical effects of a chloramine to non-surgical treatment of peri-implantitis. Material and methodsEighteen individuals diagnosed with peri-implantitis (clinical signs of inflammation and progressive bone loss) on at least two implants were included. Clinical variables; plaque accumulation (Pl), probing depth (PD), clinical attachment level (CAL) and bleeding on probing (BoP), were recorded at baseline and at 3-month follow-up. Primary clinical efficacy variable was the change in the number of sites with BoP. The implants were randomized into two different treatment groups: test and control. Both implants received supra- and submucosal debridement by ultrasonic instrumentation supplemented with hand instruments. The implants assigned to the test group first received local applications of a chloramine gel (Perisolv; RLS Global AB, Gothenburg, Sweden) followed by mechanical instrumentation. The oral hygiene was checked at 6weeks. ResultsAfter 3months, implants of both groups showed statistically significant reduction (P<0.001) in the number of BoP-positive sites compared with baseline. The reduction of BoP-positive sites in the test group changed from 0.97 (SD0.12) to 0.38 (SD +/- 0.46), and in the control group from 0.97 (SD +/- 0.12) to 0.31 (SD +/- 0.42). Between-group comparisons revealed no statistically significant differences at baseline and after 3months, for BoP or any of the other variables. ConclusionIn the present randomized clinical trial of peri-implantitis therapy; non-surgical mechanical debridement with adjunctive use of a chloramine is equally effective in the reduction of mucosal inflammation as conventional non-surgical mechanical debridement up to 3months

Antimicrobial efficacy of chlorine agents against selected oral pathogens

Objectives: Method-dependent comparison of antimicrobial agents' efficacy against oral pathogens. Materials and methods: Several sodium hypochlorite solutions (NaOCl)-Perisolv®, Carisolv® and Dakin's solution-were equated with chlorhexidine (CHX) and hydrogen peroxide (H2O2) against ten oral micro-organisms related to caries and periodontitis using different minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) techniques. Agents were adjusted to the final 70 mmol/L concentration of active chlorine molecule. Results: Apart from H2O2 and the amino acids of Perisolv®, all the agents revealed an antimicrobial effect. Agar diffusion test ranked CHX (p &lt; 0.05) as the most effective against all ten specimens, followed by the NaOCl of Perisolv® and Dakin's solution. Correspondingly, in broth microdilution on agar, CHX was the most effective in eradicating micro-organisms at 0.03 mmol/L compared with 2.2 mmol/L of Dakin's solution. In contrast, the bactericidal concentration of Dakin's solution was the most effective at 0.2 mmol/L, (p &lt; 0.001), followed by Perisolv® (2.14 mmol/L), CHX (2.38 mmol/L) and Carisolv® (3.33 mmol/L) after 5 and 10 min in broth dilution test. In live/dead analysis, 60-min exposure to a 2-fold concentration of agents resulted in two-log Aggregatibacter actinomycetemcomitans inhibition by CHX (35 mmol/L) whilst Streptococcus mutans was more susceptible, in 0.8 and 8.8 mmol/L, after 10 min to CHX and Dakin's respectively. Conclusion: Replacement of CHX with tested hypochlorite agents showed evident potential and promoted rapid antimicrobial effect. Clinical relevance: Effective antimicrobial agents are crucial in controlling pathogen-induced oral infections increasing clinical possibilities to combat oral biofilms. Additionally, CHX substitution with hypochlorite agents could eliminate CHX's adverse effects

Patients with oral lichen planus display lower levels of salivary acidic glycoproteins than individuals without oral mucosal disease

OBJECTIVES: Salivary proteins, acidic glycoproteins, and free calcium might take part in oral mucosal defence against inflammation in oral lichen planus (OLP). The study aimed to investigate whether the levels of sulfated and sialylated glycoproteins, total protein, and free calcium in saliva from patients with OLP differ from those of individuals without oral mucosal diseases. MATERIAL AND METHODS: Patients diagnosed with OLP (n = 25) and two control groups without any oral mucosal disease; age- and gender-matched controls (n = 25, 65.6 ± 2.9 years), and younger controls (n = 25, 41.8 ± 2.5 years) were included. Subjective dry mouth (xerostomia) was assessed by asking a single-item question. Chew-stimulated whole saliva was collected to measure sulfated and sialylated glycoproteins by the Alcian Blue method. The total protein was determined spectrophotometrically, and the free calcium measured using an electrode. RESULTS: The output of salivary sulfated and sialylated glycoproteins in the OLP group (21.8 ± 2.4 µg/min) was lower than in the age- and gender-matched controls (43.0 ± 2.9 µg/min, p = 0.0002), whereas the total protein and calcium output did not differ between the three groups (p &gt; 0.05). The prevalence of xerostomia was significantly higher in the OLP group compared to both control groups (p = 0.038). CONCLUSIONS: Patients with OLP showed a high prevalence of xerostomia and lower levels of salivary acidic type glycoproteins compared to the individuals without oral mucosa disease. CLINICAL RELEVANCE: It is relevant to investigate the role of acidic glycoproteins in the pathogenesis of OLP

Oral health, dental treatment, and medication related osteonecrosis of the jaw in multiple myeloma - a longitudinal cohort study

Objective: The objective of the present study was to investigate oral health status, oral health related quality of life, and identify risk factors associated with invasive dental treatment and medication related osteonecrosis of the jaw in patients with multiple myeloma. Material and methods: Patients newly diagnosed with multiple myeloma (n = 144) referred between January 2015 and September 2022 were retrospectively included. The patients underwent a thorough clinical and radiological oral examination and odontogenic infections were treated before the start of bisphosphonate treatment. The patients were followed annually, including clinical and radiological examinations. The oral health related quality of life was investigated by the OHIP-14 questionnaire. Results: Dental treatment (RR = 7.75), receiving combination antineoplastic therapy≥3 (RR =4.13), periodontitis (RR = 4.21), and reduced number of teeth (RR = 2.87) were associated with an increased risk of medication related osteonecrosis of the jaw. The response rate of the OHIP-14 questionnaire was 70.2%. Oral pain or discomfort in the mouth related to the medical treatment was reported by 30.5%. Conclusion: Dental screening and treatment planning in patients with Multiple Myeloma may result in fewer oral infections and fewer interruptions of the medical treatment of myeloma