802
The Effect of Titanium Implant Abutment Surface Irregularities Plaque Accumulation In Vivo Judith McCollum, * Robert B. O'Neal, and Jack A. Homer*
*
William A. Brennan,
*
on
Thomas E. Van
Dyke,f
study was 2-fold to: 1) evaluate in vitro the surface texture of abutments after exposure to plastic sealers, an air-powder abrasive system, rubber cup polishing with flour of pumice, and untreated control abutments; and 2) compare plaque accumulation in humans on abutments treated with the above methods. In part I, 5.5 mm abutments were instrumented for 30 seconds per 90° segment with the respective methods. The surface character was compared to untreated controls using SEM at 260X magnification. The control abutments revealed prominent milling marks and small pits; plastic sealers slightly smoothed the milling marks and created microscratches; the air-powder abrasive largely obliterated the milling marks and caused some surface pitting; the rubber cup with flour of pumice removed the milling marks and created a smooth swirl pattern. None of the instrumentation appeared to roughen the surface. In the clinical experiment (part II), four abutments, one of each type, were placed in 12 patients for a period of 7 days, during which the patients performed no oral hygiene. At the end of 7 days, the abutments were retrieved and processed for SEM. A digitizer and software program were used to determine the percent of total abutment surface area covered by plaque. The demarcation of supragingival and subgingival plaque was well delineated. The total mean percent surface area of plaque ranged from 52.06% for the air-powder abrasive to 55.29% for the plastic sealers. All abutments collected plaque, but no single treatment yielded a surface with significantly different amounts of plaque accumulation. For maintenance and prophylaxis, any of these methods may be used without damaging the abutment surface or enhancing plaque accumulation. The rubber cup with flour of pumice provides the smoothest polished abutment surface when used with light intermittent pressure. Heavy pressure with the rubber cup on an abutment may gouge the surface or round the abutment-prosthesis interface. J Periodontol 1992; 63:802The
purpose of this
titanium
implant
805.
Words: Dental implants; dental prophylaxis/methods.
Key
abutments, dental; titanium; dental plaque/prevention;
The oxide layer on the surface of titanium implant abutments is thought to be critical to their clinical success. This layer may make titanium biocompatible; therefore, every effort should be made not to damage it by scratching or transferring ions from a foreign metal.13 Further, surface scratches provide a possible area for increased plaque retention.4,5 The role of bacterial plaque is US Army DENTAC, Ft. Gordon, GA. Eastman Dental Center, Rochester, NY. Department of Clinical Investigations, DDEAMC, Ft. Gordon, GA. The opinions or assertions contained in this paper are those of the authors and are not to be construed as official or as reflecting the views of the Department of the Army, Department of Defense, or the U.S. Government.
*Department of Periodontics,
well documented as an etiologic factor in periodontal disease around natural teeth. It is also implicated in producing analogous disease around implants.6-9 Plaque accumulation has been associated with gingival bleeding710 and increased bone loss around implants.11 Maintaining the surface integrity of implant abutments during recall and prophylaxis presents a unique problem to practitioners' supportive periodontal therapy for patients with implants. There is little documentation on how to treat implant abutments. Several authors have shown that sonic, ultrasonic, and metal instruments significantly alter the titanium abutment surface.1214 The use of plastic sealers,15"18 rubber cup with mild abrasive paste,15,16 or airpowder abrasive systems15 are recommended by various
Volume 63 Number 10
McCOLLUM, O'NEAL, BRENNAN, VAN DYKE, HORNER
authors. However, few control studies have been done on the effects of these abrasives on the titanium surface.13,14 The purpose of this study is two-fold. The first is to evaluate in vitro the surface texture of titanium implant abutments after exposure to plastic sealers, an air-powder abrasive system, or rubber cup polishing with moist flour of pumice, and to compare these to untreated control abutments. The second is to compare plaque accumulation in humans on abutments treated with the above prophylaxis methods. MATERIALS AND METHODS Part I. The entire surface of forty-eight 5.5 mm implant abutments5 was utilized as a test area. A fixture was embedded in an acrylic block and the abutments attached to it prior to instrumentation. Each abutment was divided into four 90° segments by lightly scoring it with a #11 blade to help visualize areas that had been instrumented. Each abutment was instrumented with either 1) a plastic sealer; 2) a rubber cup with moist flour of pumice; 3) an air-powder abrasive for a total of 120 seconds; or 4) served as an untreated control. Each abutment was rinsed with an air/ water spray for 30 seconds, air dried, and stored in a dry 10 cc glass vial closed with a screw cap. A JEOL Model JSM 35-CF Scanning Electron Microscope was used to photograph the surface of the abutments at 260x. A subjective comparison of surface roughness was made from Polaroid photomicrographs by one investigator (JM). Part II. After abutment connection surgery and subsequent healing, 12 patients had 4 abutments, one with each type of instrumentation noted in Part I placed for a period of one week. During the one week period, the patient performed no oral hygiene. This provided intrapatient control for each set of abutments. At the end of one week, the abutments were removed. The patients' original abutments were replaced, and the patients were reinstructed in proper oral hygiene procedures. The experimental abutments were placed in chilled glutaraldehyde for a minimum of 12 hours, critical point dried, sputter coated with gold, and photographed with SEM at lOx. The mean percent of total abutment surface area covered by plaque was determined using a Summagraphics Digitizer with a Zenith 348 PC computer and Sigma Scan Software. One-way analysis of variance was used to determine statistical significance between groups and within groups. Kruskal-Wallis analysis was used to compare plaque accumulation within groups. All participants in this study signed a volunteer agreement affidavit provided by the U.S. Army. RESULTS Part I. The control abutments displayed prominent milling marks and occasional small pits (Fig. la). The air-powder abrasive largely obliterated the milling marks and caused some
surface
pitting (Fig. lb).
The
plastic sealers slightly
sBranemark, Nobelpharma USA, Inc., Waltham, MA.
803
smoothed the milling marks, and created microscratches (Fig. lc). The rubber cup with moist flour of pumice removed the milling marks and created a smooth swirl pattern (Fig. Id). None of the instrumentations appeared to roughen the abutment surface. Part II. After one week in the mouth with no oral hygiene, the demarcation on the abutments between supragingival and subgingival plaque was well delineated (Fig. 2). For the control abutments, the total mean percent surface area of plaque was 53.09%; for the plastic sealers, 55.29%; 52.06% for the air-powder abrasive; and 52.59% for the rubber cup with flour of pumice (Table 1). One-way ANOVA, at the 95% confidence level, revealed no significant difference in plaque accumulation between groups or within groups. Kruskal-Wallis analysis also revealed no significant difference within groups. The average rank ranged from 22.333 for the air-powder abrasive to 25.417 for the plastic sealers. DISCUSSION In this study, none of the tested prophylaxis methods damaged the abutment surface or significantly affected plaque accumulation on the abutments. This agrees with the findings of other investigators. Fox found no difference in the surface roughness between the control or plastic sealer abutments.13 Rapley et al. found that the rubber cup with flour of pumice left a smoother surface than the control, and that the control surface was comparable to that of the plastic sealer and an air-powder abrasive.14 There is some controversy about the role of surface roughness and plaque accumulation. Rosenberg and Ash found that root surface roughness was not related to gingival inflammation or plaque accumulation.19 Clayton and Green showed that pon tic surfaces "as smooth as possible" will collect plaque.5 Swartz and Phillips, however, found that polished surfaces had smaller bacterial counts than rough tooth surfaces.4 Using sonic or ultrasonic instruments, metal curets and sealers will damage abutment surfaces.12,14 Curets of dissimilar metal cause impaired fibroblast attachment in cell culture.20 Further research is needed to determine the effect of the oxide layer on bacterial and mammalian cell attachment to titanium abutments as well as the role of surface roughness on cell attachment. In this study epithelial attachment was not evident on any abutment surfaces under SEM. Because titanium is a soft metal, there is some concern that the interface between the abutment and prosthesis, or between the abutment and fixture, could be damaged during maintenance therapy. The rubber cup with flour of pumice slightly rounded and thinned the abutment rim when excessive pressure was applied for 2 minutes when no analog was in place to protect the abutment-rim surface (Fig. 3). This could result in the prosthesis not fitting properly, an uneven distribution of forces, and gold screw breakage. It is therefore recommended that the rubber cup with flour of
804
EFFECT OF TITANIUM IMPLANT ABUTMENT SURFACE ON
PLAQUE ACCUMULATION
J Periodontol October 1992
Figure 1 (Original magnification x260). a. Surface of a control abutment. Prominent horizontal milling marks, occasional scratching and pitting are seen. b. Surface after treatment with air-powder abrasive for 30 seconds. Milling marks are smoothed slightly, some scratches and pitting still evident, c. Surface after treatment for 30 seconds with a plastic sealer. Milling marks are slightly smoothed, vertical microscratches are seen, d. Surface after treatment for 30 seconds with the rubber cup and flour ofpumice. Milling marks are obliterated, swirl pattern from the cup is evident.
Figure 2. Abutment after firm pressure for 2 minutes using the rubber cup with flour ofpumice. The rim on left side of abutment (a) is sharp and distinct; on the right it has been rounded and thinned (b) (original magnification x20).
Table 1. Percent of Abutment Surface Covered By Week (mean ± SD of 12 patients are represented)
Plaque After
Treatment
Percent of Surface
Control
Air-powder abrasive Rubber cup with pumice Plastic sealer
53.09 52.06 52.59 55.29
± ± ± ±
1
21.7 13.6 20.8 14.6
Figure 3. Typical plaque distribution on an abutment at 7 days. Heavy supragingival plaque (a), and subgingival plaque (b) are seen (original magnification 10).
pumice, the air-powder abrasive, and possibly other devices be used with some care to avoid altering either of these interfaces. There is also controversy in the literature regarding the role of bacterial plaque in implant failure. Some authors state that since there is no periodontal ligament around an
Volume 63 Number 10
McCOLLUM, O'NEAL, BRENNAN, VAN DYKE,
HORNER
805
Osseointegration in Clinical Dentistry. Chicago, IL: Quintessence; 1985; 99-116. 3. Parr GR, Gardner LK, Toth RW. Titanium: The mystery metal of implant dentistry. Dental materials aspects. J Pros Dent 1985; 54:410Prostheses.
4. Stainless steel healing caps pfoced when the prosthesis is moved protect the abutments during polishing.
Figure
re-
implant, plaque has no path of invasion beyond the gingiva and that it plays an insignificant role in implant failure.21 That is not supported by clinical observations and research at this institution (unpublished data). It is possible to produce ligature-induced Periodontitis around implants in micropigs.22 Other authors have shown that periodontal pathogens can colonize implants,6 and that a relationship exists between periodontal pathogens and failing implants.6"8 This study shows abundant plaque accumulation, on surfaces of similar smoothness in the absence of oral hygiene, as early as one week after abutment placement. In particular, many areas of subgingival plaque accumulation were seen, and there were no areas on the abutments suggestive of an epithelial attachment. One would, therefore, have to question the statement that bacterial plaque does not play an important role in implant failure. Clinically, it is evident that plastic sealers do not remove tenacious calculus in an efficient manner. The air-powder abrasive systems are efficient for removing plaque, calculus, and stain and are easy to use with a prosthesis in place. In accessible areas, or when the prosthesis is removed, the rubber cup with flour of pumice provides the smoothest abutment surface. Both the air-powder abrasive and rubber cup with flour of pumice should be used judiciously to avoid damaging the abutment and changing the fit of the prosthesis. When the prosthesis has been removed, either plastic or stainless steel healing caps should be placed to protect the abutment-rim surface (Fig. 4). Acknowledgments
This protocol (DDEAMC 89-42) was approved by the Investigation Review Committee for research protocols at Dwight David Eisenhower Army Medical Center, Ft. Gor-
don, GA.
REFERENCES 1. Kasemo B. Biocompatibility of titanium implants: Surface science aspects. J Pros Dent 1983; 49:832-837. 2. Kasemo B, Lausmaa J. Metal selection and surface characteristics. In: Branemark P-I, Zarb G, Albrektsson T, eds. Tissue-Integrated
414. 4. Swartz ML, Phillips RW. Comparison of bacterial accumulations on rough and smooth enamel surfaces. / Periodontol 1957; 28:304-307. 5. Clayton JA, Green E. Roughness of pontic materials and dental plaque. JPros Dent 1970; 23:407-411. 6. Nakou M, Mikx FHM, Oosterwaal PJM, Kruijsen JCWM. Early microbial colonization of permucosal implants in edentulous patients. / Dent Res 1987; 66:1654-1657. 7. Mombelli A, Van Oosten MAC, Schurch E, Lang NP. The microbiota associated with successful or failing osseointegrated titanium implants. Oral Microbio! Immunol 1987; 2:145-151. 8. Sanz M, Newman MG, Nachnani S, Holt R, Stewart R, Flemmig T. Characterization of the subgingival microbial flora around endosteal sapphire dental implants in partially edentulous patients. Int J Oral Maxillofac Implants 1990; 5:247-253. 9. Becker W, Becker BE, Newman MG, Nyman S. Clinical and microbiologic findings that may contribute to dental implant failure. Int J Oral Maxillofac Implants 1990; 5:31-38. 10. Zarb G, Symington J. Osseointegrated dental implants: Preliminary report on a replication study. J Pros Dent 1983; 50:271-276. 11. Lindquist L, Rockier B, Carlsson G. Bone résorption around fixtures in edentulous patients treated with mandibular fixed tissue-integrated prostheses. J Pros Dent 1988; 59:59-63. 12. Thomson-Neal D, Evans GH, Meffert RM. Effects of various prophylactic treatments on titanium, sapphire, and hydroxyapatite-coated implants: A SEM study. Int J Periodontics Restorative Dent 1989; 9:301-311. 13. Fox SC, Moriarty JD, Kusy RP. The effects of scaling a titanium implant surface with metal and plastic instruments: An in vitro study. J Periodontol 1990; 61:485^190. 14. Rapley JW, Swan RH, Hallmon WW, Mills MP. The surface characteristics produced by various oral hygiene instruments and materials on titanium implant abutments. Int J Oral Maxillofac Implants 1990; 5:47-52. 15. Stefani L. The care and maintenance of the dental implant patient. / Dent Hygiene 1988; 62:447. 16. Orton GS, Steele DL, Wolinsky LE. The dental professional's role in monitoring and maintenance of tissue-integrated prothesis. Int J Oral Maxillofac Implants 1989; 4:305-310. 17. Brough K, Johnson R, Carr P, Daffron P. The dental hygienist's role in the maintenance of osseointegrated dental implants. J Dent Hygiene 1988; 62:448. 18. Balshi TJ. Hygiene maintenance procedures for patients treated with the tissue integrated prosthesis (osseointegration). Quintessence Int 1986; 17:95-102. 19. Rosenberg RM, Ash MM. The effect of root roughness on plaque accumulation and gingival inflammation. / Periodontol 1974; 45:146150. 20. Dmytryk JJ, Fox SC, Moriarty JD. The effects of scaling titanium implant surfaces with metal and plastic instruments on cell attachment. / Periodontol 1990; 61:491^196. 21. Apse P, Zarb GA, Schmitt A, Lewis DW. The longitudinal effectiveness of osseointegrated dental implants. The Toronto study: Perimplant mucosal response. Int J Periodontics Restorative Dent 1991; 11:95-111. 22. Hickey JS, O'Neal RB, Scheidt MJ, Strong SL, Turgeon DK. Evaluation of the microorganisms present in induced perioimplantitis in the micropig. J Periodontol 1991; 62:548-551.
Send reprint requests to: Director, Periodontics Residency Program, Ft. Gordon, GA 30905. Accepted for publication April 10, 1992.
The Effect of Titanium Implant Abutment Surface Irregularities Plaque Accumulation In Vivo Judith McCollum, * Robert B. O'Neal, and Jack A. Homer*
*
William A. Brennan,
*
on
Thomas E. Van
Dyke,f
study was 2-fold to: 1) evaluate in vitro the surface texture of abutments after exposure to plastic sealers, an air-powder abrasive system, rubber cup polishing with flour of pumice, and untreated control abutments; and 2) compare plaque accumulation in humans on abutments treated with the above methods. In part I, 5.5 mm abutments were instrumented for 30 seconds per 90° segment with the respective methods. The surface character was compared to untreated controls using SEM at 260X magnification. The control abutments revealed prominent milling marks and small pits; plastic sealers slightly smoothed the milling marks and created microscratches; the air-powder abrasive largely obliterated the milling marks and caused some surface pitting; the rubber cup with flour of pumice removed the milling marks and created a smooth swirl pattern. None of the instrumentation appeared to roughen the surface. In the clinical experiment (part II), four abutments, one of each type, were placed in 12 patients for a period of 7 days, during which the patients performed no oral hygiene. At the end of 7 days, the abutments were retrieved and processed for SEM. A digitizer and software program were used to determine the percent of total abutment surface area covered by plaque. The demarcation of supragingival and subgingival plaque was well delineated. The total mean percent surface area of plaque ranged from 52.06% for the air-powder abrasive to 55.29% for the plastic sealers. All abutments collected plaque, but no single treatment yielded a surface with significantly different amounts of plaque accumulation. For maintenance and prophylaxis, any of these methods may be used without damaging the abutment surface or enhancing plaque accumulation. The rubber cup with flour of pumice provides the smoothest polished abutment surface when used with light intermittent pressure. Heavy pressure with the rubber cup on an abutment may gouge the surface or round the abutment-prosthesis interface. J Periodontol 1992; 63:802The
purpose of this
titanium
implant
805.
Words: Dental implants; dental prophylaxis/methods.
Key
abutments, dental; titanium; dental plaque/prevention;
The oxide layer on the surface of titanium implant abutments is thought to be critical to their clinical success. This layer may make titanium biocompatible; therefore, every effort should be made not to damage it by scratching or transferring ions from a foreign metal.13 Further, surface scratches provide a possible area for increased plaque retention.4,5 The role of bacterial plaque is US Army DENTAC, Ft. Gordon, GA. Eastman Dental Center, Rochester, NY. Department of Clinical Investigations, DDEAMC, Ft. Gordon, GA. The opinions or assertions contained in this paper are those of the authors and are not to be construed as official or as reflecting the views of the Department of the Army, Department of Defense, or the U.S. Government.
*Department of Periodontics,
well documented as an etiologic factor in periodontal disease around natural teeth. It is also implicated in producing analogous disease around implants.6-9 Plaque accumulation has been associated with gingival bleeding710 and increased bone loss around implants.11 Maintaining the surface integrity of implant abutments during recall and prophylaxis presents a unique problem to practitioners' supportive periodontal therapy for patients with implants. There is little documentation on how to treat implant abutments. Several authors have shown that sonic, ultrasonic, and metal instruments significantly alter the titanium abutment surface.1214 The use of plastic sealers,15"18 rubber cup with mild abrasive paste,15,16 or airpowder abrasive systems15 are recommended by various
Volume 63 Number 10
McCOLLUM, O'NEAL, BRENNAN, VAN DYKE, HORNER
authors. However, few control studies have been done on the effects of these abrasives on the titanium surface.13,14 The purpose of this study is two-fold. The first is to evaluate in vitro the surface texture of titanium implant abutments after exposure to plastic sealers, an air-powder abrasive system, or rubber cup polishing with moist flour of pumice, and to compare these to untreated control abutments. The second is to compare plaque accumulation in humans on abutments treated with the above prophylaxis methods. MATERIALS AND METHODS Part I. The entire surface of forty-eight 5.5 mm implant abutments5 was utilized as a test area. A fixture was embedded in an acrylic block and the abutments attached to it prior to instrumentation. Each abutment was divided into four 90° segments by lightly scoring it with a #11 blade to help visualize areas that had been instrumented. Each abutment was instrumented with either 1) a plastic sealer; 2) a rubber cup with moist flour of pumice; 3) an air-powder abrasive for a total of 120 seconds; or 4) served as an untreated control. Each abutment was rinsed with an air/ water spray for 30 seconds, air dried, and stored in a dry 10 cc glass vial closed with a screw cap. A JEOL Model JSM 35-CF Scanning Electron Microscope was used to photograph the surface of the abutments at 260x. A subjective comparison of surface roughness was made from Polaroid photomicrographs by one investigator (JM). Part II. After abutment connection surgery and subsequent healing, 12 patients had 4 abutments, one with each type of instrumentation noted in Part I placed for a period of one week. During the one week period, the patient performed no oral hygiene. This provided intrapatient control for each set of abutments. At the end of one week, the abutments were removed. The patients' original abutments were replaced, and the patients were reinstructed in proper oral hygiene procedures. The experimental abutments were placed in chilled glutaraldehyde for a minimum of 12 hours, critical point dried, sputter coated with gold, and photographed with SEM at lOx. The mean percent of total abutment surface area covered by plaque was determined using a Summagraphics Digitizer with a Zenith 348 PC computer and Sigma Scan Software. One-way analysis of variance was used to determine statistical significance between groups and within groups. Kruskal-Wallis analysis was used to compare plaque accumulation within groups. All participants in this study signed a volunteer agreement affidavit provided by the U.S. Army. RESULTS Part I. The control abutments displayed prominent milling marks and occasional small pits (Fig. la). The air-powder abrasive largely obliterated the milling marks and caused some
surface
pitting (Fig. lb).
The
plastic sealers slightly
sBranemark, Nobelpharma USA, Inc., Waltham, MA.
803
smoothed the milling marks, and created microscratches (Fig. lc). The rubber cup with moist flour of pumice removed the milling marks and created a smooth swirl pattern (Fig. Id). None of the instrumentations appeared to roughen the abutment surface. Part II. After one week in the mouth with no oral hygiene, the demarcation on the abutments between supragingival and subgingival plaque was well delineated (Fig. 2). For the control abutments, the total mean percent surface area of plaque was 53.09%; for the plastic sealers, 55.29%; 52.06% for the air-powder abrasive; and 52.59% for the rubber cup with flour of pumice (Table 1). One-way ANOVA, at the 95% confidence level, revealed no significant difference in plaque accumulation between groups or within groups. Kruskal-Wallis analysis also revealed no significant difference within groups. The average rank ranged from 22.333 for the air-powder abrasive to 25.417 for the plastic sealers. DISCUSSION In this study, none of the tested prophylaxis methods damaged the abutment surface or significantly affected plaque accumulation on the abutments. This agrees with the findings of other investigators. Fox found no difference in the surface roughness between the control or plastic sealer abutments.13 Rapley et al. found that the rubber cup with flour of pumice left a smoother surface than the control, and that the control surface was comparable to that of the plastic sealer and an air-powder abrasive.14 There is some controversy about the role of surface roughness and plaque accumulation. Rosenberg and Ash found that root surface roughness was not related to gingival inflammation or plaque accumulation.19 Clayton and Green showed that pon tic surfaces "as smooth as possible" will collect plaque.5 Swartz and Phillips, however, found that polished surfaces had smaller bacterial counts than rough tooth surfaces.4 Using sonic or ultrasonic instruments, metal curets and sealers will damage abutment surfaces.12,14 Curets of dissimilar metal cause impaired fibroblast attachment in cell culture.20 Further research is needed to determine the effect of the oxide layer on bacterial and mammalian cell attachment to titanium abutments as well as the role of surface roughness on cell attachment. In this study epithelial attachment was not evident on any abutment surfaces under SEM. Because titanium is a soft metal, there is some concern that the interface between the abutment and prosthesis, or between the abutment and fixture, could be damaged during maintenance therapy. The rubber cup with flour of pumice slightly rounded and thinned the abutment rim when excessive pressure was applied for 2 minutes when no analog was in place to protect the abutment-rim surface (Fig. 3). This could result in the prosthesis not fitting properly, an uneven distribution of forces, and gold screw breakage. It is therefore recommended that the rubber cup with flour of
804
EFFECT OF TITANIUM IMPLANT ABUTMENT SURFACE ON
PLAQUE ACCUMULATION
J Periodontol October 1992
Figure 1 (Original magnification x260). a. Surface of a control abutment. Prominent horizontal milling marks, occasional scratching and pitting are seen. b. Surface after treatment with air-powder abrasive for 30 seconds. Milling marks are smoothed slightly, some scratches and pitting still evident, c. Surface after treatment for 30 seconds with a plastic sealer. Milling marks are slightly smoothed, vertical microscratches are seen, d. Surface after treatment for 30 seconds with the rubber cup and flour ofpumice. Milling marks are obliterated, swirl pattern from the cup is evident.
Figure 2. Abutment after firm pressure for 2 minutes using the rubber cup with flour ofpumice. The rim on left side of abutment (a) is sharp and distinct; on the right it has been rounded and thinned (b) (original magnification x20).
Table 1. Percent of Abutment Surface Covered By Week (mean ± SD of 12 patients are represented)
Plaque After
Treatment
Percent of Surface
Control
Air-powder abrasive Rubber cup with pumice Plastic sealer
53.09 52.06 52.59 55.29
± ± ± ±
1
21.7 13.6 20.8 14.6
Figure 3. Typical plaque distribution on an abutment at 7 days. Heavy supragingival plaque (a), and subgingival plaque (b) are seen (original magnification 10).
pumice, the air-powder abrasive, and possibly other devices be used with some care to avoid altering either of these interfaces. There is also controversy in the literature regarding the role of bacterial plaque in implant failure. Some authors state that since there is no periodontal ligament around an
Volume 63 Number 10
McCOLLUM, O'NEAL, BRENNAN, VAN DYKE,
HORNER
805
Osseointegration in Clinical Dentistry. Chicago, IL: Quintessence; 1985; 99-116. 3. Parr GR, Gardner LK, Toth RW. Titanium: The mystery metal of implant dentistry. Dental materials aspects. J Pros Dent 1985; 54:410Prostheses.
4. Stainless steel healing caps pfoced when the prosthesis is moved protect the abutments during polishing.
Figure
re-
implant, plaque has no path of invasion beyond the gingiva and that it plays an insignificant role in implant failure.21 That is not supported by clinical observations and research at this institution (unpublished data). It is possible to produce ligature-induced Periodontitis around implants in micropigs.22 Other authors have shown that periodontal pathogens can colonize implants,6 and that a relationship exists between periodontal pathogens and failing implants.6"8 This study shows abundant plaque accumulation, on surfaces of similar smoothness in the absence of oral hygiene, as early as one week after abutment placement. In particular, many areas of subgingival plaque accumulation were seen, and there were no areas on the abutments suggestive of an epithelial attachment. One would, therefore, have to question the statement that bacterial plaque does not play an important role in implant failure. Clinically, it is evident that plastic sealers do not remove tenacious calculus in an efficient manner. The air-powder abrasive systems are efficient for removing plaque, calculus, and stain and are easy to use with a prosthesis in place. In accessible areas, or when the prosthesis is removed, the rubber cup with flour of pumice provides the smoothest abutment surface. Both the air-powder abrasive and rubber cup with flour of pumice should be used judiciously to avoid damaging the abutment and changing the fit of the prosthesis. When the prosthesis has been removed, either plastic or stainless steel healing caps should be placed to protect the abutment-rim surface (Fig. 4). Acknowledgments
This protocol (DDEAMC 89-42) was approved by the Investigation Review Committee for research protocols at Dwight David Eisenhower Army Medical Center, Ft. Gor-
don, GA.
REFERENCES 1. Kasemo B. Biocompatibility of titanium implants: Surface science aspects. J Pros Dent 1983; 49:832-837. 2. Kasemo B, Lausmaa J. Metal selection and surface characteristics. In: Branemark P-I, Zarb G, Albrektsson T, eds. Tissue-Integrated
414. 4. Swartz ML, Phillips RW. Comparison of bacterial accumulations on rough and smooth enamel surfaces. / Periodontol 1957; 28:304-307. 5. Clayton JA, Green E. Roughness of pontic materials and dental plaque. JPros Dent 1970; 23:407-411. 6. Nakou M, Mikx FHM, Oosterwaal PJM, Kruijsen JCWM. Early microbial colonization of permucosal implants in edentulous patients. / Dent Res 1987; 66:1654-1657. 7. Mombelli A, Van Oosten MAC, Schurch E, Lang NP. The microbiota associated with successful or failing osseointegrated titanium implants. Oral Microbio! Immunol 1987; 2:145-151. 8. Sanz M, Newman MG, Nachnani S, Holt R, Stewart R, Flemmig T. Characterization of the subgingival microbial flora around endosteal sapphire dental implants in partially edentulous patients. Int J Oral Maxillofac Implants 1990; 5:247-253. 9. Becker W, Becker BE, Newman MG, Nyman S. Clinical and microbiologic findings that may contribute to dental implant failure. Int J Oral Maxillofac Implants 1990; 5:31-38. 10. Zarb G, Symington J. Osseointegrated dental implants: Preliminary report on a replication study. J Pros Dent 1983; 50:271-276. 11. Lindquist L, Rockier B, Carlsson G. Bone résorption around fixtures in edentulous patients treated with mandibular fixed tissue-integrated prostheses. J Pros Dent 1988; 59:59-63. 12. Thomson-Neal D, Evans GH, Meffert RM. Effects of various prophylactic treatments on titanium, sapphire, and hydroxyapatite-coated implants: A SEM study. Int J Periodontics Restorative Dent 1989; 9:301-311. 13. Fox SC, Moriarty JD, Kusy RP. The effects of scaling a titanium implant surface with metal and plastic instruments: An in vitro study. J Periodontol 1990; 61:485^190. 14. Rapley JW, Swan RH, Hallmon WW, Mills MP. The surface characteristics produced by various oral hygiene instruments and materials on titanium implant abutments. Int J Oral Maxillofac Implants 1990; 5:47-52. 15. Stefani L. The care and maintenance of the dental implant patient. / Dent Hygiene 1988; 62:447. 16. Orton GS, Steele DL, Wolinsky LE. The dental professional's role in monitoring and maintenance of tissue-integrated prothesis. Int J Oral Maxillofac Implants 1989; 4:305-310. 17. Brough K, Johnson R, Carr P, Daffron P. The dental hygienist's role in the maintenance of osseointegrated dental implants. J Dent Hygiene 1988; 62:448. 18. Balshi TJ. Hygiene maintenance procedures for patients treated with the tissue integrated prosthesis (osseointegration). Quintessence Int 1986; 17:95-102. 19. Rosenberg RM, Ash MM. The effect of root roughness on plaque accumulation and gingival inflammation. / Periodontol 1974; 45:146150. 20. Dmytryk JJ, Fox SC, Moriarty JD. The effects of scaling titanium implant surfaces with metal and plastic instruments on cell attachment. / Periodontol 1990; 61:491^196. 21. Apse P, Zarb GA, Schmitt A, Lewis DW. The longitudinal effectiveness of osseointegrated dental implants. The Toronto study: Perimplant mucosal response. Int J Periodontics Restorative Dent 1991; 11:95-111. 22. Hickey JS, O'Neal RB, Scheidt MJ, Strong SL, Turgeon DK. Evaluation of the microorganisms present in induced perioimplantitis in the micropig. J Periodontol 1991; 62:548-551.
Send reprint requests to: Director, Periodontics Residency Program, Ft. Gordon, GA 30905. Accepted for publication April 10, 1992.
