You will be presented with a collection of medical randomized controlled trial (RCT) reports addressing a shared clinical question -- for instance, the efficacy of a medical intervention on a disease or condition. Given the titles and abstracts of these reports, your task is to generate the conclusion of the systematic review article synthesizing the key findings. Your conclusion should be a few sentences long. In your response, include only the conclusion and no other text. The RCT reports are below.



Title 1:
The effect of an oral hygiene program on oral levels of volatile sulfur compounds (VSC).
Abstract 1:
Volatile sulfur compounds ( VSCs ) produced by bacteria in niches of the oral cavity play a major role in the etiology of bad breath , and can be easily detected by a portable sulfide monitor ( Halimeter ) . To investigate the effect of an oral hygiene program on VSC levels , Halimeter readings were taken from 55 healthy dental students during a course in oral hygiene training , including instruction on brushing , flossing and professional tooth cleaning .  Ten students who received no oral hygiene training served as a negative control . The oral hygiene status was measured using the papillary bleeding index ( PBI ) . PBI and VSC values did not show significant changes during the study period of 10 weeks in the control group . In the test group , PBI values significantly decreased compared to baseline and the control , indicating that the oral hygiene program had a benefit on the oral hygiene status . The VSC values also decreased significantly during the study period compared to baseline and the control . It was concluded that in a group of dental students , a thorough oral hygiene training program was capable of reducing the oral level of VSC Halimeter readings


Title 2:
Oral prophylaxis and its effects on halitosis-associated and inflammatory parameters in patients with chronic periodontitis.
Abstract 2:
OBJECTIVE A controlled clinical trial was conducted to evaluate the effects of oral prophylaxis on halitosis-associated , immunological and microbiological parameters . METHODS Thirty subjects were included in this controlled clinical trial ( patients with generalized chronic periodontitis and controls without clinical attachment loss ; each n = 15 ) .  Before oral prophylaxis and 14 days after ( including tongue cleaning ) volatile sulphur compounds ( VSC ) , organoleptic scores and a tongue coating index were evaluated . The levels of IL-1β , IL-8 , IL-10 and MMP-8 were measured in GCF , and also major periodontal pathogens were detected . Data were statistically analysed using anova and paired t-test . RESULTS Supragingival plaque and calculus removal with combined tongue cleaning was able to reduce significantly ( P < 0.05 ) the VSC values in both groups ( no significant differences between both groups ) . Two weeks after periodontal debridement , the VSC values were observed in the periodontitis group , but not in the control group , similar to the baseline values . The difference between the groups was statistically significant ( P < 0.05 ) . Only a repeated prophylaxis session in the periodontitis group was able to reduce VSC values significantly in comparison with baseline ( P < 0.05 ) . Organoleptic scores ( 10 and 30 cm ) were significantly different ( P < 0.05 ) between both groups before and after the treatment . Periodontal pathogens and host-derived markers were not significantly affected by a single prophylaxis session . CONCLUSIONS Oral prophylaxis may result in a significant decrease in VSC values . However , in periodontal diseases , a more complex treatment seems to be necessary


Title 3:
The impact of periodontal therapy and the adjunctive effect of antiseptics on breath odor-related outcome variables: a double-blind randomized study.
Abstract 3:
BACKGROUND Bad breath is often caused by periodontitis and /or tongue coating . This study followed the impact of initial periodontal therapy on several halitosis-related outcome variables over a 6-month period . Organoleptic ratings are often uncomfortable for the patient and have several disadvantages . They are , for instance , influenced by external parameters ( e.g. , food intake and cosmetics ) and need to be calibrated among research ers worldwide . A second aim was to evaluate the reliability of saliva incubation as an in vitro indirect test for breath recording . METHODS In this double-blind , r and omized , medium-term , parallel study 45 moderate periodontitis patients without obvious tongue coating were enrolled . Besides a one-stage , full-mouth disinfection and oral hygiene improvement ( including daily tongue scraping ) , patients were instructed to rinse daily for 6 months with one of the following products ( r and omly allocated ) : chlorhexidine ( CHX ) 0.2 % + alcohol , CHX 0.05 % + cetyl pyridinium chloride ( CPC ) 0.05 % without alcohol ( a new formulation ) , or a placebo solution . At baseline and 3 and 6 months , a series of parameters were recorded including : concentration of volatile sulfide compounds ( VSC ) , tongue coating , and an estimation of the microbial load ( at anterior and posterior parts of the tongue , saliva , dental plaque ) . The intraoral VSC ratings were compared to in vitro VSC recordings and organoleptic evaluations of the headspace air from 1 and 2 hours incubated saliva ( 0.5 ml , 37 degrees C , anaerobic chamber ) . RESULTS Even though the initial VSC values were not high ( + /-90 ppb with only 18 patients revealing more than 100 ppb ) , significant ( P < 0.05 ) reductions could be achieved in the CHX and CHX + CPC group , and to a lower extent in the placebo group ( P = 0.10 ) . Tongue scraping result ed in a significant reduction ( P < or = 0.05 ) of the tongue coating up to month 6 in the placebo and CHX + CPC group , but not in the CHX group ( confusion due to staining ) . The CHX and CHX + CPC group showed , in comparison to baseline , significant ( P < 0.001 ) reductions in the number of anaerobic species in the supragingival plaque , in the saliva , and on the anterior part of the tongue . For the posterior part of the tongue the microbial changes remained < or = 0.3 log values ( P > 0.05 ) . For the placebo group , the microbial changes never reached a level of significance ( < or = 0.3 log values ) . A strong correlation was found between the intraoral VSC ratings and the 1-hour ( r = 0.48 , P < 0.0001 ; r = 0.54 , P = 0.0003 for baseline data only ) and 2-hour ( r = 0.43 , P < 0.0001 ) VSC production of incubated saliva . The latter also correlated very strongly ( r = 0.71 ) with the number of anaerobic species in the saliva . The VSC values and organoleptic ratings of the incubated saliva also correlated strongly with each other ( r = 0.64 for 1-hour and 0.73 for 2-hour incubation ) . CONCLUSIONS The results of this study indicate that in patients with moderate periodontitis , initial periodontal therapy including tongue scraping did not have a significant effect on the microbial load of the tongue and had only a weak impact on the VSC level , except when combined with a mouthrinse . Saliva incubation can be used as an indirect way to score breath odor . It offers simplicity , objectivity , and is less invasive


Title 4:
Reduction of oral levels of volatile sulfur compounds (VSC) by professional toothcleaning and oral hygiene instruction in non-halitosis patients.
Abstract 4:
PURPOSE The aim of the study was to determine the longitudinal effect of an oral hygiene program on oral levels of volatile sulfur compounds ( VSC ) . MATERIAL S AND METHODS The study subjects were r and omly selected from patients attending a student course in operative dentistry and from staff members of our dental clinic . The test group ( n = 30 ) received an oral hygiene training including professional toothcleaning ( PTC ) , oral hygiene instruction , and motivation . The control group ( n = 10 ) received no particular treatment .  None of the subjects suffered from bad breath nor performed regular tongue cleaning . At baseline , immediately after PTC , one week , and four weeks thereafter we measured the oral hygiene status by means of the  papillary bleeding index ( PBI ) and the oral concentrations of VSC by using a  portable sulfide monitor ( Halimeter ) . RESULTS Immediately after PTC , as well as one week , and four weeks after entering the program the PBI and the VSC-levels were significantly decreased as compared to the baseline values and the control group . VSCs were decreased by 34.9 % ( + /- 6.3 ) after PTC , 33.2 % ( + /- 7.1 ) one week , and 27.9 % ( + /- 5.8 ) four weeks thereafter . CONCLUSION The present study shows that in a group of patients without bad breath , an oral hygiene training program including professional toothcleaning , motivation and instruction of self-applied oral hygiene procedures is capable of reducing both papillary bleeding and oral levels of VSC Halimeter readings over the observation period of four weeks


Title 5:
Clinical trial of oral malodor treatment in patients with periodontal diseases.
Abstract 5:
BACKGROUND AND OBJECTIVE Only a few clinical research studies have assessed different therapeutic approaches to oral malodor in subjects affected by periodontal diseases . The aim of this study was to evaluate the effects of periodontal treatment and tongue cleaning on oral malodor parameters in periodontitis and gingivitis patients . MATERIAL AND METHODS The subjects were 102 periodontitis and 116 gingivitis patients with oral malodor . Oral malodor was measured by organoleptic test and Oral Chroma ™ . Oral health status , including tooth conditions , periodontal health , tongue coating and proteolytic activity of the BANA test in tongue coating were assessed . Subjects in each periodontal disease group were r and omly assigned into two subgroups depending on the sequence of treatment : periodontal treatment and tongue cleaning . Oral malodor and oral health parameters were compared by groups and sequence of treatment . RESULTS For subjects in the periodontitis group , there were statistically significant reductions in oral malodor after periodontitis treatment or tongue cleaning ; however , major reductions were found after periodontitis treatment . For those in the gingivitis group , there were also statistically significant reductions in oral malodor after gingivitis treatment or tongue cleaning , but the most marked reductions were observed after tongue cleaning . At the completion of treatment , all oral malodor parameters fell below the threshold levels in all subgroups . CONCLUSION The present study indicated that periodontal treatment played an important role and tongue cleaning contributed to a lesser extent to reduction in oral malodor in periodontitis patients . In contrast , tongue cleaning alone can be the primary approach to reduce oral malodor in gingivitis patients
Based on best available evidence , PTC and SRP in combination with oral hygiene instructions reduced  VSC values in patients with oral halitosis and /or periodontal diseases , independent of tongue cleaning and the use of mouth rinses