This study by Laky et al. is a single-centre, double-blinded randomised placebo-controlled clinical trial, examining the effects of micronutrient supplementation in combination with non-surgical hygiene phase therapy (nsHPT) for Stage III and IV periodontal disease. The study was carried out at the Medical University of Vienna (Austria), School of Dentistry. The patients enrolled in the study were randomised to receive a commercially available multi-nutrient supplement (containing: vitamin C, vitamin E, zinc, selenium, alpha-lipoic-acid, cranberry extract, grapeseed extract, and coenzyme Q10) or a cellulose placebo to take for 2 months, alongside a course of non-surgical hygiene phase therapy. At baseline, the patients had a periodontal index screening (PSI) performed. Patients scoring >3 and meeting the inclusion criteria were enrolled in the trial. Oral hygiene instruction and patient education was performed, followed by 1 or more sessions of nsHPT depending on the clinical assessment of each patient, and a full periodontal probing depth (PPD) chart was recorded. The patients were then randomised to receive either the multi-nutrient supplement or the placebo to take twice daily for 8 weeks. Following this 8-week period the PPD as well as bleeding on probing (BOP), gingival recession (GR) and clinical attachment loss (CAL) were measured. The randomisation was carried out by a study-independent member of staff at the centre using a computer programme. A total of 149 patients were assessed for eligibility for this trial. Out of these patients, 83 were deemed to be unsuitable for the trial as they failed to meet the inclusion criteria, and 24 declined to participate. A total of 42 patients were then randomised to each arm of the study. The inclusion criteria included patients with Stage III and IV periodontal disease. Patients were deemed eligible if they met the following criteria: presence of 18 or more scorable teeth (excluding 3rd molars); >4 teeth with PPD of >6 mm; CAL > 5 mm, and no previous periodontal treatment in the past. Percentage bone loss at the most severe site, smoking status, and presence of diabetes and diabetic control were all taken into consideration. Patients were deemed ineligible for the trial if they were pregnant or under 18 years old. Exclusion criteria also included: recent periodontal abscess; a past or current co-morbidity which may confound the results of the study or endanger patients partaking in the study (i.e. malignancy, rheumatoid arthritis, and other severe systemic conditions); and obesity. PPD was used as the primary variable in this study. Other measured outcomes such as GR, CAL, BOP and other measurements taken, such as papillary bleeding index (PBI) and papillary inflamed surface area (PISA), were considered as secondary outcome variables. A variety of tests were used in order to assess the collected data. The Kolmogorov‒Smirnov test and Levene test were used for the equality of variances, and ICC and 95% CI were used when comparing periodontal chartings for PPD (in mm). Chi-square or Fisher tests were used for categorical data between intervention and placebo. The baseline and reevaluation data was compared using the McNemar test. All data was analysed using statistical software. Significant data is indicated by a p value < 0.05. The number of patients included for analysis was reduced to n = 20 for the intervention group and n = 19 for the placebo group. Patients were lost due to a variety of reasons including need for antibiotics and lost to follow-up. The authors concluded that in each arm of the trial, periodontal and hygiene parameters improved overall. The results show that the intervention group had a significantly higher reduction in PPD; however, following data analysis, these findings were found to be statistically insignificant. The authors conclude that the addition of a multi-nutrient supplement, alongside nsHPT for patients undergoing treatment for Stage III and IV periodontal disease, showed a reduction in PPD and BOP when compared with a placebo and nsHPT.