Effects of ultrasonic and sonic sealers on dental plaque microflora in vitro and in vivo
p. Baehni, B. Thito, B, Chapuis and D. Pernet Division o1 Preventive Dentistry. School of Dental Medicine, Medfcal Faculty, University of Geneva, Switzerland
Baehni P. Thih B. Chapuis B and Pernet D: Effects of ultrasonic and sonic sealers on dental plague microflora in vitro and in vivo. J Clin Periodontol 1992:19: 455-459. Abstract. The effects of ultrasonic and sonic sealers on the subgingival microflora were investigated in vitro and in vivo. In the in vitro investigation, 27 plaque samples collected from periodontal pockets were submitted to ultrasonic and sonic vibrations for 10, 30 and 60 s. Bacterial suspensions were examined by darkfieid microscopy to detect qualitative changes and cultured to evaluate the total number of cultivable bacteria. Microscopic counts following both instrumentations showed a decrease in the proportions of spirochetes and motile rods and an increase in the "A of coccoids and rods. The changes were directly related to the time-period of instrumentation. Comparison between both types of instrumentation showed significant differences and more pronounced changes were observed with the ultrasonic than the sonic sealer. Spirochetes and motile rods were reduced to approximately 0.]% after ultrasonic treatment versus 24.7% after sonic instrumentation. Cultural observations showed a marked increase in total number of coiony-forming units following both treatments. The chnical investigation included 66 periodontal pockets which were instrumented subgingivaliy for 10 and 30 s with ultrasonic or sonic sealers. Qualitative changes were similar to those observed in vitro, i.e., reduction in spirochete and motile rod counts as well as the other morphotypes with an increase in coccoid cells. Total counts of bacteria were reduced following debridement. No difference in the microscopic or cultural data was found between ultrasonic and sonic instrumentation.
Ultrasonic and sonic sealers are often utilized to eliminate calculus and dental plaque deposits. Ultrasonic sealers operale at frequencies between 25,000 and 42,000 Hz generated by magnetostriction or piezo-electricity with an amplitude of the scaling tip ranging from 7-28 jum (Walmsley et al, 1984). Sonic or air turbine sealers differ in their mode of operation and their physical characteristics (Council on dental materials, instruments, and equipment 1985): vibrations are produced by an air rotor with operating frequencies in the range of 10,000 to 16,000 Hz; the amplitude of the tip ranging from 50-150 /jm may be influenced by the type of insert used and by the pressure of the air input into the instrument (Gankerseer &. Walmsley 1987), Extensive work based mostly on clinieal or histological observations has been published on the effects of ultrasonic sealers on dental and periodontal tissues. Many studies have compared the results
of ultrasonic debridement with hand scaling (Torfason et al. 1979, Badersten et al. 1981, 1984) and most of them have shown that ultrasonic sealers are effective in removing subgingiva! bacterial deposits adherent to tooth surfaces (Thornton & Gamick 1982, Stende & Schaffer 1961, Breininger et al. 1987). Microbial studies concerning the effects of ultrasonic sealers on dental plaque microflora have shown that subgingival debridement with ultrasonics provoke changes in the microbial composition of dental plaque (Oosterwaal et al, 1987, Leon & Vogel 1987, Loos et al. 1988). Information on the effectiveness of sonic sealers is more limited (Loos et al, 1987, Gellin et al. 1986, Lie & Leknes 1985) and to our knowledge no study has evaluated their effects on plaque microorganisms . The purpose of this study w as therefore to investigate and compare the effects of ultrasonic and sonic vibrations produced by sealers on dental plaque microfiora.
Key words: ultrasoiiic sealer; sonic sealer; plaque; subgingival microflora; debridement. Accepted for publication 23 May 1991
Material and Methods Ultrasonic and sonic instrumentation in vitro
35 subgingival plaque samples were collected with a sterile periodontal curette from sites presenting evidence of periodontal breakdown with probing depth > 5 mm. Specimens were suspended in 0,5 ml of 0.9% NaCl sterile solution and dispersed by Vortex mixing for 20 s. Only specimens containing 30 to 60% spirochetes and motile rods as determined by dark field were used for the study; as a result only 27 samples out of the original 35 samples were suitable, 500 fA aliquots of plaque samples were then transferred into plastic microtubes (PAE-15 Milian Instruments SA). Each aliquot was submitted to ultrasonic or sonic vibrations or left untreated. Ultrasonic vibrations were generated by piezo-electricity using a Piezon-Master* sealer (Electro Medical Systems SA, Le Sentier, Switzerland), The hand-
456
Baehrti et al.
Table I. Bacterial distribution in sticcessive subgingival plaque samples 1st sample 2nd sample 3rd sample 38.4-1-16,0 6.0-1-4,0 17.1 + 8,9 21,4±6,6 17,0±9,8
spirochetes motile rods cocci rods filaments
36,4+14,5 5,8 + 3.6 20,9+13,5 18,9 ±6,3 17,9±11.9
36.4±13,3 3.8 + 2,5 18,6±8,4 23,4 ±9,3 17,4±10,6
Results (%) (mean±SD), piece was mounted with a type A tip operating at a frequency of 28,500 Hz, The power setting was adjusted on medium as recommended by the manufacturer. The sonic scaier was a Titan-S* (Syntex Dental Products Inc. Valley Forge, PA), tnounted with an uttiversal tip type 56801 operating at frequencies < 10,000 Hz; the air pressure input was 2,7x10' N/m', For each instrument, the tip was inserted into the microtube and maintained in the suspension. The bacterial samples (Piezon-Master n = 12, Titan-S n=15) were submitted to vibrations for 10 s. 20 s. 30 s and 60 s, 20 //I of each bacterial preparation were immediately processed for dark field microscopy and observed at a magnification of X 1,200 (Zeiss. Germany), Bacteria were classified as coccoid cells, rods, filaments and fusiforras, motile rods and spirochetes (Listgarten & Hellden 1978), A total of 100 microorganisms was counted and the results for each category expressed as a percentage of the total flora. In 10 experiments
specimens were also evaluated for bacterial growth. 100 /il of the bacterial suspension were transferred into transport fluid (RTF. Loesche et al, 1972), serially diluted and 0,1 ml was plated in duplicate on supplemented Trypticase soy agar with 5% sheep blood. Plates were placed under anaerobic conditions (GasPack*, BBL Microbiology Systems. Cockeysvilie. MD) and incubated for 6 days at 37-C, Plates with lO'' or 10- dilution were exatnined at a magnification of X 12 and the total number of colony-forming units (CFU) per plate determined.
Ultrasonic and sonic subgingivai instrumentation in periodontal pockets
A total of 66 periodontal pockets in 31 patients (aged 30 to 70) were included in the study. Sites were selected on the basis of clinical and microbiological criteria. Probing depths were deeper than 4 mm (.x- = 6.7+l,3 mm) with radiographic evidence of alveolar bone de-
struction greater than 25% and the subgingival microflora had to harbor at least 30% spirochetes and motile rods. All selected sites were located in the proximal region on the facial aspect of mono- or pluriradicular teeth, Supragingival plaque was first eliminated and subgingival plaque was sampled by inserting 2 paper points (Maillefer, Switzerland, ISO no, 25) in the pocket for 10 s. Paper points were removed and placed in 200 fil 0,9% NaCl sterile solution. Sites were then treated in a random fashion either with sonic or ultrasonic instrument (PiezonMaster n = 46. Titan-S n = 20). The tip of the scaier was placed in the pocket until resistance was felt and a sweepitig movement along the root surface was performed during instrumentation. Instrumentation was carried out without anesthesia with a water flow through the handpiece for cooling the tip. The insert used was the A tip for the PiezonMaster and the Perio tip (no, 56420) for the Titan-S, Subgingival piaque was again sampled after 10 and 30 s of instrumentation using paper points. Plaque specimens obtained before and after various treatment times were observed by dark field microscopy and the % of the various bacterial morphotypes determined. For 20 sites plaque samples collected before and after 30 s of treatment were also evaluated for bacterial growth and processed as previously described.
Table 2. Relative bacterial distribution following in vitro instrumentation Time of instrumentation
32,5±14,7 36,1 ±11,6
Motile rods ultrasonic sonic
18,2±10.8
30 s
10 s
Os
Spirochetes ultrasonic sonic
60 s
O.I ±0,3 23,9±11,8
NS
7,8±5.7 29,6±6.9
I,9±3,2 23,5±7.4
NS
O,8±l,5 2,7±2.0
,.
0,0±0.0 l,0±2.I
„
0,0±0.0 0,8±2.l
Cocci ultrasonic sonic
14,9 ±9,5 19,3±11.7
NS
30,1 ±9,8 24,5 ±10.4
,,. ^S
44,0+14,3 29,6 ±14,3
.,„ f"^
50,5 + 13.1 28,8 ±14,2
Rods ultrasonic sonic
I7.3±4,9 I7.O±5,5
NS
43,1 ±10,9 21.7±5,5
„
42,3 ±11,5 26,8 ±7,5
„
40,1 ±11,1 29,6 ±9,5
Filaments ultrasonic sonic
18,2 + 8,9 16,3±7,3
NS
18,3±7,7 21,0±«,3
Results (%) (mean±SD) NS: not significant. • p
p. Baehni, B. Thito, B, Chapuis and D. Pernet Division o1 Preventive Dentistry. School of Dental Medicine, Medfcal Faculty, University of Geneva, Switzerland
Baehni P. Thih B. Chapuis B and Pernet D: Effects of ultrasonic and sonic sealers on dental plague microflora in vitro and in vivo. J Clin Periodontol 1992:19: 455-459. Abstract. The effects of ultrasonic and sonic sealers on the subgingival microflora were investigated in vitro and in vivo. In the in vitro investigation, 27 plaque samples collected from periodontal pockets were submitted to ultrasonic and sonic vibrations for 10, 30 and 60 s. Bacterial suspensions were examined by darkfieid microscopy to detect qualitative changes and cultured to evaluate the total number of cultivable bacteria. Microscopic counts following both instrumentations showed a decrease in the proportions of spirochetes and motile rods and an increase in the "A of coccoids and rods. The changes were directly related to the time-period of instrumentation. Comparison between both types of instrumentation showed significant differences and more pronounced changes were observed with the ultrasonic than the sonic sealer. Spirochetes and motile rods were reduced to approximately 0.]% after ultrasonic treatment versus 24.7% after sonic instrumentation. Cultural observations showed a marked increase in total number of coiony-forming units following both treatments. The chnical investigation included 66 periodontal pockets which were instrumented subgingivaliy for 10 and 30 s with ultrasonic or sonic sealers. Qualitative changes were similar to those observed in vitro, i.e., reduction in spirochete and motile rod counts as well as the other morphotypes with an increase in coccoid cells. Total counts of bacteria were reduced following debridement. No difference in the microscopic or cultural data was found between ultrasonic and sonic instrumentation.
Ultrasonic and sonic sealers are often utilized to eliminate calculus and dental plaque deposits. Ultrasonic sealers operale at frequencies between 25,000 and 42,000 Hz generated by magnetostriction or piezo-electricity with an amplitude of the scaling tip ranging from 7-28 jum (Walmsley et al, 1984). Sonic or air turbine sealers differ in their mode of operation and their physical characteristics (Council on dental materials, instruments, and equipment 1985): vibrations are produced by an air rotor with operating frequencies in the range of 10,000 to 16,000 Hz; the amplitude of the tip ranging from 50-150 /jm may be influenced by the type of insert used and by the pressure of the air input into the instrument (Gankerseer &. Walmsley 1987), Extensive work based mostly on clinieal or histological observations has been published on the effects of ultrasonic sealers on dental and periodontal tissues. Many studies have compared the results
of ultrasonic debridement with hand scaling (Torfason et al. 1979, Badersten et al. 1981, 1984) and most of them have shown that ultrasonic sealers are effective in removing subgingiva! bacterial deposits adherent to tooth surfaces (Thornton & Gamick 1982, Stende & Schaffer 1961, Breininger et al. 1987). Microbial studies concerning the effects of ultrasonic sealers on dental plaque microflora have shown that subgingival debridement with ultrasonics provoke changes in the microbial composition of dental plaque (Oosterwaal et al, 1987, Leon & Vogel 1987, Loos et al. 1988). Information on the effectiveness of sonic sealers is more limited (Loos et al, 1987, Gellin et al. 1986, Lie & Leknes 1985) and to our knowledge no study has evaluated their effects on plaque microorganisms . The purpose of this study w as therefore to investigate and compare the effects of ultrasonic and sonic vibrations produced by sealers on dental plaque microfiora.
Key words: ultrasoiiic sealer; sonic sealer; plaque; subgingival microflora; debridement. Accepted for publication 23 May 1991
Material and Methods Ultrasonic and sonic instrumentation in vitro
35 subgingival plaque samples were collected with a sterile periodontal curette from sites presenting evidence of periodontal breakdown with probing depth > 5 mm. Specimens were suspended in 0,5 ml of 0.9% NaCl sterile solution and dispersed by Vortex mixing for 20 s. Only specimens containing 30 to 60% spirochetes and motile rods as determined by dark field were used for the study; as a result only 27 samples out of the original 35 samples were suitable, 500 fA aliquots of plaque samples were then transferred into plastic microtubes (PAE-15 Milian Instruments SA). Each aliquot was submitted to ultrasonic or sonic vibrations or left untreated. Ultrasonic vibrations were generated by piezo-electricity using a Piezon-Master* sealer (Electro Medical Systems SA, Le Sentier, Switzerland), The hand-
456
Baehrti et al.
Table I. Bacterial distribution in sticcessive subgingival plaque samples 1st sample 2nd sample 3rd sample 38.4-1-16,0 6.0-1-4,0 17.1 + 8,9 21,4±6,6 17,0±9,8
spirochetes motile rods cocci rods filaments
36,4+14,5 5,8 + 3.6 20,9+13,5 18,9 ±6,3 17,9±11.9
36.4±13,3 3.8 + 2,5 18,6±8,4 23,4 ±9,3 17,4±10,6
Results (%) (mean±SD), piece was mounted with a type A tip operating at a frequency of 28,500 Hz, The power setting was adjusted on medium as recommended by the manufacturer. The sonic scaier was a Titan-S* (Syntex Dental Products Inc. Valley Forge, PA), tnounted with an uttiversal tip type 56801 operating at frequencies < 10,000 Hz; the air pressure input was 2,7x10' N/m', For each instrument, the tip was inserted into the microtube and maintained in the suspension. The bacterial samples (Piezon-Master n = 12, Titan-S n=15) were submitted to vibrations for 10 s. 20 s. 30 s and 60 s, 20 //I of each bacterial preparation were immediately processed for dark field microscopy and observed at a magnification of X 1,200 (Zeiss. Germany), Bacteria were classified as coccoid cells, rods, filaments and fusiforras, motile rods and spirochetes (Listgarten & Hellden 1978), A total of 100 microorganisms was counted and the results for each category expressed as a percentage of the total flora. In 10 experiments
specimens were also evaluated for bacterial growth. 100 /il of the bacterial suspension were transferred into transport fluid (RTF. Loesche et al, 1972), serially diluted and 0,1 ml was plated in duplicate on supplemented Trypticase soy agar with 5% sheep blood. Plates were placed under anaerobic conditions (GasPack*, BBL Microbiology Systems. Cockeysvilie. MD) and incubated for 6 days at 37-C, Plates with lO'' or 10- dilution were exatnined at a magnification of X 12 and the total number of colony-forming units (CFU) per plate determined.
Ultrasonic and sonic subgingivai instrumentation in periodontal pockets
A total of 66 periodontal pockets in 31 patients (aged 30 to 70) were included in the study. Sites were selected on the basis of clinical and microbiological criteria. Probing depths were deeper than 4 mm (.x- = 6.7+l,3 mm) with radiographic evidence of alveolar bone de-
struction greater than 25% and the subgingival microflora had to harbor at least 30% spirochetes and motile rods. All selected sites were located in the proximal region on the facial aspect of mono- or pluriradicular teeth, Supragingival plaque was first eliminated and subgingival plaque was sampled by inserting 2 paper points (Maillefer, Switzerland, ISO no, 25) in the pocket for 10 s. Paper points were removed and placed in 200 fil 0,9% NaCl sterile solution. Sites were then treated in a random fashion either with sonic or ultrasonic instrument (PiezonMaster n = 46. Titan-S n = 20). The tip of the scaier was placed in the pocket until resistance was felt and a sweepitig movement along the root surface was performed during instrumentation. Instrumentation was carried out without anesthesia with a water flow through the handpiece for cooling the tip. The insert used was the A tip for the PiezonMaster and the Perio tip (no, 56420) for the Titan-S, Subgingival piaque was again sampled after 10 and 30 s of instrumentation using paper points. Plaque specimens obtained before and after various treatment times were observed by dark field microscopy and the % of the various bacterial morphotypes determined. For 20 sites plaque samples collected before and after 30 s of treatment were also evaluated for bacterial growth and processed as previously described.
Table 2. Relative bacterial distribution following in vitro instrumentation Time of instrumentation
32,5±14,7 36,1 ±11,6
Motile rods ultrasonic sonic
18,2±10.8
30 s
10 s
Os
Spirochetes ultrasonic sonic
60 s
O.I ±0,3 23,9±11,8
NS
7,8±5.7 29,6±6.9
I,9±3,2 23,5±7.4
NS
O,8±l,5 2,7±2.0
,.
0,0±0.0 l,0±2.I
„
0,0±0.0 0,8±2.l
Cocci ultrasonic sonic
14,9 ±9,5 19,3±11.7
NS
30,1 ±9,8 24,5 ±10.4
,,. ^S
44,0+14,3 29,6 ±14,3
.,„ f"^
50,5 + 13.1 28,8 ±14,2
Rods ultrasonic sonic
I7.3±4,9 I7.O±5,5
NS
43,1 ±10,9 21.7±5,5
„
42,3 ±11,5 26,8 ±7,5
„
40,1 ±11,1 29,6 ±9,5
Filaments ultrasonic sonic
18,2 + 8,9 16,3±7,3
NS
18,3±7,7 21,0±«,3
Results (%) (mean±SD) NS: not significant. • p
