Hugoson 2007.

Methods	Trial design: parallel (4 arms) Location: 2 clinics: a large Public Dental Service (PDS) clinic and a private 2‐dentist practice in Jönköping, Sweden Number of centres: 2 Study Duration: recruitment and follow‐up dates not reported. Participants followed‐up at 3 years
Participants	Participants: 400 subjects aged 20 years to 27 years, 211 males and 189 females, participated in the study Inclusion criteria: young adults regularly seeking dental care where the individual was not planning to move from Jönköping within the next few years Exclusion criteria: not reported Age at baseline (years): 20 to 27 Gender: 189 (47%) females and 211 (53%) males Number randomised: 400 participants Number evaluated: 348 participants. The dropout rates during the study were 2.3% (9 individuals), 4.3% (17 individuals), and 6.5% (26 individuals) after 1 year, 2 years, and 3 years, respectively, or a total of 13% (52 individuals) after 3 years
Interventions	In all test groups, a soft toothbrush (Swedish brand 'TePe', Malmo, Sweden) and either toothpicks (TePe) or dental floss (Johnson & Johnson dentotape, Sollentuna, Sweden) were used at the oral hygiene instruction sessions. Instructions on the Bass method (Bass 1954a) were given if the subject's own brushing technique proved unsatisfactory, and all subjects were advised to start their brushing lingually in the lower jaw molar region. The patients were informed, according to routine procedures at the clinic, that the best way of establishing the habit of interdental cleaning is to clean the teeth proximally before brushing. In groups 2 and 3, the oral hygiene instruction or re‐instruction was carried out after the participants used a disclosing Diaplack tablet. The proximal aids, dental floss or toothpicks, were chosen depending on anatomical conditions (e.g. crowded teeth), and the degree of gingivitis when toothpicks were recommended in cases with severe proximal inflammation or 'open' proximal spaces. The subjects were asked to demonstrate and practice the cleaning technique in their own mouths Group 1: the control group: no organized prophylactic measures for caries and gingivitis/periodontitis within the framework of the study but had to answer a questionnaire about knowledge of dental diseases and oral hygiene behaviour. The subjects were recalled at 12‐month intervals for follow‐up examinations, identical to the baseline examination, over the next 3 years Group 2: the Karlstad model. All individuals received prophylactic care every second month (6 times/year) according to the Karlstad model for adult individuals. At the first visit, approximately 30 minutes, information on caries and gingivitis/periodontitis was presented and oral hygiene instruction was given based on plaque disclosure. At the next 5 visits, approximately 20 minutes each at 2‐month intervals, the individual's oral status was reviewed and, when necessary, information or oral hygiene instruction was repeated. Half the number of the individuals were also randomly chosen to have no other preventive measures (20). The other individuals were randomly chosen to undergo professional tooth cleaning at each visit. The cleaning was performed crosswise in 2 quadrants, which meant that the teeth in the right maxilla and the left mandible were professionally cleaned in 25 individuals (21) and in the left maxilla and the right mandible in 25 individuals (22). The 1‐year follow‐up comprised the same measures undertaken at the baseline examination. The remedial measures undertaken during the first year were repeated for the next 2 years with yearly follow‐ups, the last 1 being the 3‐year follow‐up NOTE: group (21) and group (22) received prophylactic care every 2 months and are not included further Group 3: individual educational. All individuals underwent an individual basic preventive programme according to the National Swedish Board of Health and Welfare. The programme comprised 3 visits at 2‐week intervals during the first year. At the first visit, approximately 30 minutes, information on caries and gingivitis/periodontitis was presented and oral hygiene instruction was given based on plaque disclosure. The individual's oral status was reviewed at the next 2 visits of approximately 20 minutes and 15 minutes, respectively, and when necessary, information and hygiene instruction were repeated. The 1‐year follow‐up comprised the measures undertaken at the baseline examination. Directly after the follow‐up, the individuals were scheduled for a 30‐minute repetition of indicated information and oral hygiene instruction. The same was done at the 2‐year follow‐up, after which the individuals were called for a 3‐year follow‐up Group 4: group education. All individuals underwent the remedial measures recommended by the National Swedish Board of Health and Welfare for dental health preventive programmes for adults but modified for group‐based information with 3 visits that had essentially the same content as the programme followed by Group 3. The time required was approximately 60 minutes for the first visit, 30 minutes for the second and 15 minutes for the third.The programme was conducted as group activities with 10 individuals in each group NOTE: given the group nature of the intervention this group is not included further Prophylaxis provided: "Caries restorative measures and scaling were undertaken when needed to bring the oral hygiene of all participants up to the same baseline standard" "Each year, all the test subjects were given enough fluoride toothpaste (Acta 0.22% sodium fluoride corresponding to 0.1% fluoride, Astra‐Wallco AB) to last for 1 year (8 tubes)" Member of dental team delivering intervention: hygienist Frequency of intervention: Group 1: 4 visits total, no OHA. Group 20: 6 visits, each with repeated OHA. Group 3: 4 visits, OHA provided 3 times Intensity of intervention (length of time): Group 1: no OHA. Grp 20: approximately 130 minutes. Group 3: approximately 125 minutes Setting: mixed setting: public dental setting and primary care Disease level: young adults regularly seeking dental care
Outcomes	Presence of plaque and gingivitis, clinical caries, restorative dental care, attachment level, pocket depth, and supra and subgingival calculus Plaque and gingivitis were recorded on the buccal, lingual, mesial, and distal tooth surfaces of all teeth except the third molars. The presence of plaque was recorded after the tooth surfaces were dried with air according to the criteria for the plaque index (PLI). A PLI score of 1, 2, or 3 was considered to be a positive indicator of plaque, and the surface was registered as positive. The presence of gingivitis was recorded according to the criteria for the gingival index (GI). A GI score of 2 or 3 was used as a measure of gingivitis. Thus, bleeding was registered after the pocket probe had been applied to the opening of the gingival pocket and passed along the tooth surface in question (Löe 1967)
Notes	Funding: "Financial support to this study has been given by the Jönköping County Council and The Institute for postgraduate dental Education, Jönköping, Sweden" "The cost analysis took into account both the direct and indirect costs where direct costs were the time the personnel sat aside the individual for each program and indirect costs the patients sat aside and the relation between these costs" Sample size calculation: not reported Adverse effects: not reported Declarations/conflicts of interest: "The authors declare that they have no conflict of interests"
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The subjects were randomly assigned, by help of a randomising table, into 4 groups of 100 individuals each. Responsible for the randomisation was one of the authors"
Allocation concealment (selection bias)	Unclear risk	Comment: insufficient information on allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quotes: "The study was performed as a randomized controlled study with the outcome of the result blind"; "The remedial measures were carried out by another dental hygienist. The programmes followed a detailed, written working plan to ensure that all patients received the same information and instructions" Comment: blinding of participants was not possible; it is unclear the influence this would have on the risk of bias for this domain
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "The dental hygienist who carried out the baseline examination of the patient also examined the patient annually and was unaware of which group the patient belonged to and which programme of preventive measures the participant was following"
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Quote: (Hugoson 2007) "The dropout rates during the study were 2.3% (9 individuals), 4.3% (17 individuals), and 6.5% (26 individuals) after 1, 2, and 3 years, respectively, or a total of 13% (52 individuals) after 3 years. The main reasons for the dropouts (see Hugoson 2003 ). The dropouts were evenly distributed between the groups" Previous paper from research group reported (Hugoson 2003): "The dropout rates during the study's first 3 years were 1% (4 individuals), 1.8% (7 individuals) and 3.8% (15 individuals) after 1, 2 and 3 years, respectively, in total 6.5% (26 individuals) after 3 years" Comment: disparity between publications regarding dropout numbers. No response from contact author regarding further clarification
Selective reporting (reporting bias)	High risk	Comment: a number of clinical outcomes not reported upon (e.g. clinical caries, restorative dental care (other than 1 extraction), pocket depths, attachment levels and calculus). No response from contact author regarding further information
Other bias	Low risk	No apparent other bias