J. Dent. 1991; 19: 366-368
366
Radiopacity of direct ceramic inlay restoratives* 0. M. El-Mowafy, J. W. Brown and D. McComb Restorative
Department,
Faculty of Dentistry,
University
of Toronto, Ontario, Canada
ABSTRACT The radiopacity of two new ceramic restorative materials (Dicer MGC and Cerec Vita Blocks) manufactured for use in producing direct inlays with the ‘Cerec CAD-CAM’ system was determined. Dicer MGC had a radiopacity significantly greater than that of enamel, while Cerec Vita Blocks had a radiopacity significantly less than that of dentine. It is concluded that Dicer MGC has a radiopacity suitable for its use as an intracoronal restorative for posterior teeth. The low radiopacity of Cerec Vita Blocks means that the use of radiopaque luting cement is essential to permit detection of secondary caries around restorations of this material. Furthermore, marginal overhangs around restorations made from Cerec Vita Blocks will be difficult to detect radiographically. KEY WORDS: Ceramics, Inlays, Radiopacity J. Dent
1991;
19: 366-368
(Received 20 February 1991;
reviewed 4 April 1991;
accepted 7 June 1991)
Correspondence should be addressed to: Dr 0. M. El-Mowafy, Restorative Department, University of Toronto, 124 Edward Street, Toronto, Ontario M5G 1 G8 Canada.
INTRODUCTION Previous studies have indicated that posterior composite materials should be more radiopaque than enamel or at least possess similar radiopacity to enamel (Lutz et al.,
1984; Goshima, 1985; Omer et al., 1986) in order to allow detection of overhangs, defects in restorations and secondary caries. The same principle is applicable to any new intracoronal restorative material intended for use in the posterior teeth. Recently, two ceramic inlay materials were introduced to the profession for use in the manufacture of direct inlays with a machine that utilizes a CAD-CAM system (Cerec, Siemens, Bensheim, Germany). The purpose of this study was to measure the radiopacities of these two new ceramic materials and compare them with those of tooth enamel and dentine, two posterior composites and a conventional porcelain.
MATERIALS
AND METHODS
Specimens measuring 7.5 X 7.5 mm with a thickness of 2.5 mm were cut from blocks of two ceramic materials (Dicer MGC, L.D. Caulk Division, Dentsply International Inc., Milford, DE, USA, Cerec Vita Blocks, Vita Zahnfabrik *This paper was presented at the IADR Meeting held in Acapulco, Mexico, 17-21 April 1991. @ 1991 Butterworth-Heinemann 0300-5712/91/060366-03
Ltd.
Faculty of Dentistry,
H. Rauter GmbH &Co. KG, Sackingen, Germany) using a microslicing machine (Accutom, Struers Co., Copenhagen, Denmark). Similar specimens were prepared from a direct composite resin (Occlusin Uni-Tips, Coe Laboratories Inc., Chicago, IL, USA) and a composite inlay material (Isosit, Ivoclar AG, Schann, Liechtenstein) using a silicone mould. Same size specimens were also prepared from a conventional porcelain (Vita VMK 68, Vita Zahnfabrik H. Rauter GmbH & Co. KG Sackingen, Germany) using the same mould lined with a thin layer of tin foil. Following firing, the conventional porcelain specimens were ground to the required thickness using 600 grit silicon paper. Three specimens were obtained from each material. Three longitudinal sections of the same thickness were also obtained from three recently extracted permanent molar teeth using the microslicing machine. The specimens were randomly divided into three groups, each group containing one specimen of each material. Each group was placed on a Kodak X-ray film, Ultraspeed D (Eastman Kodak Co., Rochester, NY, USA) together with an aluminium step wedge having a thickness increasing by 1 mm for each step to 14 mm. Using a dental X-ray machine (General Electric, model 46-181121G1, MIL/ Milwaukee, WI, USA), the film was exposed at 65 kVp with a focus-object distance of 40 cm and a time of 0.8 s.
El-Mowafy
et al.: Radiopacity
of ceramic restorative
materials
367
Following standard techniques, the films were developed in an automatic processor at a temperature of 25 f 1“C using a 4.5-min cycle. The optical density of the materials was measured by means of a transmission densitometer (Macbeth TD-504, Macbeth Corp., Newburgh, NY, USA) following methods similar to those described previously (Abou-Tab1 et al., 1979; Cook,1981). A minimum of four readings was obtained from each radiograph for each material and the data were analysed statistically by Fisher’s multiple range test of one-way ANOVA. Optical density measurements of the materials were used to express their radiopacity in terms of aluminium equivalent (mm Al). RESULTS A radiograph of all the materials tested along with a tooth section is shown in Fig. 1. The ranking of the materials examined according to their degree of radiopacity is set out in Table I. The statistical analysis showed that there were significant differences between all the materials (P < 0.0001) except for Dicer MGC and Isosit; and Vita VMK porcelain and dentine. DISCUSSION Porcelain inlays were introduced to dentistry before the turn of this century (Huff, 1928). However, their use never gained continued popularity for a number of reasons, including difficulty in obtaining a good marginal lit with consequent dissolution of the cement in the oral fluids, and excessive wear of the opposing dentition (Qualtrough et al., 1990). Nevertheless, new materials and new techniques have been recently developed which can overcome these problems. It is now possible to etch the fitting surface of a porcelain or a ceramic inlay (Deines, 1986). Using a resin-based cement the inlay can then be bonded to the tooth structure after etching of the enamel and application of an appropriate dentine bonding agent. Some of the newer ceramic inlay materials are less hard than conventional porcelain and this may reduce the incidence of problems of abrasive wear on opposing teeth. With such developments, coupled with the increasing public demand for reliable aesthetic posterior restorations,
Fig. 1. Representative radiograph showing specimens of the materials tested along with a tooth section. A, Dicer MGC; B, Vita VMK 68; C, Cerec Vita Blocks; D, Occlusin; E, Isosit.
it is anticipated that the use of improved porcelain or ceramic inlays will gain popularity. In this study, it was found that Dicer MGC had radiopacity greater than that of enamel, whereas Cerec Vita had radiopacity less than that of dentine. This indicates that the former material is more suitable than the latter in this respect as it will readily allow detection of marginal overhangs, proximal contour and secondary caries in conventional radiographs. However, if a radiopaque luting cement is used in conjunction with the latter material (Cerec Vita Blocks) this will allow detection of recurrent caries, but detection of marginal overhangs will still be difficult to achieve. It is interesting to note that Vita VMK has radiopacity greater than that of Cerec Vita Blocks; however, its radiopacity is only comparable to that of dentine. Both composites had radiopacities greater than that of enamel which indicates their radiographic suitability for use in posterior teeth. The radiopacity values reported in this study for enamel and dentine (1.84 mm Al/l.0 mm enamel and 1.16 mm Al/ 1.0 mm dentine) are comparable to those reported by Williams and Billington (1987) (2.1 mm Al/l.0 mm enamel and 1.0 mm Al/l.0 mm dentine) and by Stanford et al. (1987) (2.22 mm Al/l.0 mm enamel and 0.70 mm Al/ 1.0 mm dentine). For enamel and dentine sections 2.5 mm thick, Abou-Tab1 et al. (1979) reported radiopacity values
Table 1. Materials tested and their radiopacity expressed as equivalent thickness of aluminium. Bar indicates materials not significantly different Optical density
Radiopacity (mm AV2.5 mm material)
Radiopacity (mm Al/l. 0 mm material)
Material
Mean
s.d.
Occlusin Uni-tips
0.541
0.032
z
2.84
lsosit Dicer MGC Enamel Vita VMK 68 Dentine Cerec Vita Blocks
0.647 0.664 0.767 0.963 1.006 1.206
0.039 0.034 0.043 0.043 0.059 0.053
5:5 4.6 3.1 2.9 1.9
2.32 2.20 I 1.84 1.24 1.16 0.76
368
J. Dent
199 1; 19:
No. 6
Table II. Radiopacity of the tested materials when film exposure was conducted at 70 kVp instead of 65 kVp Material Occlusin Uni-tips lsosit Dicer MGC Enamel Vita VMK 68 Dentine Cerec Vita Blocks
Radiopacity in mm Al 7.8 5.9 5.8 4.4 3.3 2.8 1.9
of 4.0 mm Al and 2.5 mm Al for enamel and dentine, respectively. These values are also comparable to the values reported in the present study (4.6 mm Al for enamel and 2.9 mm Al for dentine). Variations in radiopacity values between different studies can be due to a number of factors which include: speed of the film used, exposure time, voltage used and processing of the film. For example, in the present study when the radiopacities of the same specimens of materials were measured under the same conditions with the exception of using a voltage of 70 kVp instead of 65 kVp, slightly different values were obtained (Table Ir). Although the pattern of the variations among these values is not uniform, the magnitude of the variations is very small and insignificant and most important the ranking of the materials remains unchanged. Other factors mentioned above may influence the radiopacity values to a greater extent. However, for comparative studies like the present one, variations in the radiopacity values of the examined materials as related to values reported in other studies will have no bearing on the ranking of the materials within the individual study. It is concluded that the Dicer MGC material has the
radiopacity required for use as a posterior intracoronal ceramic restorative material, whereas the application of Cerec Vita Blocks as an intracoronal posterior restorative is dependent on the radiopacity of the luting cement for the purpose of recurrent caries detection. Acknowledgements The authors of this article would like to thank the Siemens Company, Canada for their supply of the ceramic inlay materials.
References Abou-Tab1 Z. M., Tidy D. C. and Combe E. C. (1979) Radiopacity of composite restorative materials. Br. Dent. J. 147, 187-188. Cook W. D. (1981) An investigation of the radiopacity of composite restorative materials. Aust Dent J. 26, 105-l 12. Deines D. N. (1986) The etched porcelain inlay/onlay restoration. Missouri Dent. .l. 66, 26-28. Goshima T. (1985) The radiopacity of composite restorative materials. Dentomaxillofac. Radiol. (suppl. 7, abstr. 79). Huff M. D. (1928) Porcelain inlays and their substitutes. J. Am. Dent Assoc. 15, 1505-1508. Lutz R. W., Phillips R. W., Roulet J. F. et al. (1984) In vivo and in vitro wear of potential posterior composites. J. Dent. Res. 63, 914-920. Omer 0. E., Wilson N. H. F. and Watts D. C. (1986) Radiopacity of posterior composites. J. Dent. 14, 178-179. Qualtrough A J. E., Wilson N. H. F. and Smith G. A (1990) The porcelain inlay: a historical view. Oper. Dent. 15, 61-70. Stanford C. M., Fan P. L. and Schoenfeld C. M. (1987) Radiopacity of light-cured posterior composite resins. J. Am. Dent. Assoc. 115,722-724. Williams J. A. and Billington R. W. (1987) A new technique for measuring the radiopacity of natural tooth substance and restorative materials. J. Oral Rebabif. 14, 267-269.
Book Review Periodontics: A Practical Approach. J. B. Keiser. Pp. 544. 1990. Oxford, Wright (an imprint of Butterworth-Heinemann). Hardback, f 65.00 The author of Periodontics: A Practical Approach is Dr J. Bernard Keiser, Senior Lecturer and Honorary Consultant in Periodontology at the Eastman Dental Hospital in London. The author’s intent was an effort to combine current findings in clinical and basic research in periodontology with his 25 years of clinical experience to suggest a practical approach to therapy. The book is divided into three parts, each with specific objectives and characteristics. Pat-t I is devoted to the basics of periodontal disease and is authored by eminent contributors in the field. The topics covered include: the periodontium in health and disease; pathogenesis, microbiology and epidemiology of periodontal disease; and health education including plaque control. The material is thoroughly reviewed and is ‘state of the art’; however, supporting scientific data could have been included rather than providing a list of pertinent literature at the end of each chapter in the limited section of, ‘References for further study’. Part II describes therapeutic techniques recommended by the author for the treatment of various periodontal conditions and is illustrated clearly with diagrams and sequential
photographs. The 19 chapters of this section begin with the author’s rationale for periodontal therapy, including surgical and non-surgical treatment, and conclude with the maintenance phase of this therapy. The section on surgical therapy is interesting as it includes the author’s own classification and nomenclature of various procedures, concepts which are unsupported by references or resources for further reading. These personal views comprise approximately 75 per cent of the book. Part III presents a review of current research findings to support the clinical approach recommended in Part II. These chapters present extensive reviews of pertinent topics and are supported by excellent citations. It is unfortunate that the author did not combine Parts II and III since this would have combined the discussion of current scientific information with the therapy recommended. Such an approach would have better integrated the contents of the book, resulting in a more cohesive text and avoiding the minor inconsistencies. Nonetheless, it does represent a good source of information for practitioners and students alike on the practice of periodontics, presenting the clinical approach to periodontal treatment of an experienced clinician, while thoroughly reviewing current scientific findings. R. G. Caffesse
366
Radiopacity of direct ceramic inlay restoratives* 0. M. El-Mowafy, J. W. Brown and D. McComb Restorative
Department,
Faculty of Dentistry,
University
of Toronto, Ontario, Canada
ABSTRACT The radiopacity of two new ceramic restorative materials (Dicer MGC and Cerec Vita Blocks) manufactured for use in producing direct inlays with the ‘Cerec CAD-CAM’ system was determined. Dicer MGC had a radiopacity significantly greater than that of enamel, while Cerec Vita Blocks had a radiopacity significantly less than that of dentine. It is concluded that Dicer MGC has a radiopacity suitable for its use as an intracoronal restorative for posterior teeth. The low radiopacity of Cerec Vita Blocks means that the use of radiopaque luting cement is essential to permit detection of secondary caries around restorations of this material. Furthermore, marginal overhangs around restorations made from Cerec Vita Blocks will be difficult to detect radiographically. KEY WORDS: Ceramics, Inlays, Radiopacity J. Dent
1991;
19: 366-368
(Received 20 February 1991;
reviewed 4 April 1991;
accepted 7 June 1991)
Correspondence should be addressed to: Dr 0. M. El-Mowafy, Restorative Department, University of Toronto, 124 Edward Street, Toronto, Ontario M5G 1 G8 Canada.
INTRODUCTION Previous studies have indicated that posterior composite materials should be more radiopaque than enamel or at least possess similar radiopacity to enamel (Lutz et al.,
1984; Goshima, 1985; Omer et al., 1986) in order to allow detection of overhangs, defects in restorations and secondary caries. The same principle is applicable to any new intracoronal restorative material intended for use in the posterior teeth. Recently, two ceramic inlay materials were introduced to the profession for use in the manufacture of direct inlays with a machine that utilizes a CAD-CAM system (Cerec, Siemens, Bensheim, Germany). The purpose of this study was to measure the radiopacities of these two new ceramic materials and compare them with those of tooth enamel and dentine, two posterior composites and a conventional porcelain.
MATERIALS
AND METHODS
Specimens measuring 7.5 X 7.5 mm with a thickness of 2.5 mm were cut from blocks of two ceramic materials (Dicer MGC, L.D. Caulk Division, Dentsply International Inc., Milford, DE, USA, Cerec Vita Blocks, Vita Zahnfabrik *This paper was presented at the IADR Meeting held in Acapulco, Mexico, 17-21 April 1991. @ 1991 Butterworth-Heinemann 0300-5712/91/060366-03
Ltd.
Faculty of Dentistry,
H. Rauter GmbH &Co. KG, Sackingen, Germany) using a microslicing machine (Accutom, Struers Co., Copenhagen, Denmark). Similar specimens were prepared from a direct composite resin (Occlusin Uni-Tips, Coe Laboratories Inc., Chicago, IL, USA) and a composite inlay material (Isosit, Ivoclar AG, Schann, Liechtenstein) using a silicone mould. Same size specimens were also prepared from a conventional porcelain (Vita VMK 68, Vita Zahnfabrik H. Rauter GmbH & Co. KG Sackingen, Germany) using the same mould lined with a thin layer of tin foil. Following firing, the conventional porcelain specimens were ground to the required thickness using 600 grit silicon paper. Three specimens were obtained from each material. Three longitudinal sections of the same thickness were also obtained from three recently extracted permanent molar teeth using the microslicing machine. The specimens were randomly divided into three groups, each group containing one specimen of each material. Each group was placed on a Kodak X-ray film, Ultraspeed D (Eastman Kodak Co., Rochester, NY, USA) together with an aluminium step wedge having a thickness increasing by 1 mm for each step to 14 mm. Using a dental X-ray machine (General Electric, model 46-181121G1, MIL/ Milwaukee, WI, USA), the film was exposed at 65 kVp with a focus-object distance of 40 cm and a time of 0.8 s.
El-Mowafy
et al.: Radiopacity
of ceramic restorative
materials
367
Following standard techniques, the films were developed in an automatic processor at a temperature of 25 f 1“C using a 4.5-min cycle. The optical density of the materials was measured by means of a transmission densitometer (Macbeth TD-504, Macbeth Corp., Newburgh, NY, USA) following methods similar to those described previously (Abou-Tab1 et al., 1979; Cook,1981). A minimum of four readings was obtained from each radiograph for each material and the data were analysed statistically by Fisher’s multiple range test of one-way ANOVA. Optical density measurements of the materials were used to express their radiopacity in terms of aluminium equivalent (mm Al). RESULTS A radiograph of all the materials tested along with a tooth section is shown in Fig. 1. The ranking of the materials examined according to their degree of radiopacity is set out in Table I. The statistical analysis showed that there were significant differences between all the materials (P < 0.0001) except for Dicer MGC and Isosit; and Vita VMK porcelain and dentine. DISCUSSION Porcelain inlays were introduced to dentistry before the turn of this century (Huff, 1928). However, their use never gained continued popularity for a number of reasons, including difficulty in obtaining a good marginal lit with consequent dissolution of the cement in the oral fluids, and excessive wear of the opposing dentition (Qualtrough et al., 1990). Nevertheless, new materials and new techniques have been recently developed which can overcome these problems. It is now possible to etch the fitting surface of a porcelain or a ceramic inlay (Deines, 1986). Using a resin-based cement the inlay can then be bonded to the tooth structure after etching of the enamel and application of an appropriate dentine bonding agent. Some of the newer ceramic inlay materials are less hard than conventional porcelain and this may reduce the incidence of problems of abrasive wear on opposing teeth. With such developments, coupled with the increasing public demand for reliable aesthetic posterior restorations,
Fig. 1. Representative radiograph showing specimens of the materials tested along with a tooth section. A, Dicer MGC; B, Vita VMK 68; C, Cerec Vita Blocks; D, Occlusin; E, Isosit.
it is anticipated that the use of improved porcelain or ceramic inlays will gain popularity. In this study, it was found that Dicer MGC had radiopacity greater than that of enamel, whereas Cerec Vita had radiopacity less than that of dentine. This indicates that the former material is more suitable than the latter in this respect as it will readily allow detection of marginal overhangs, proximal contour and secondary caries in conventional radiographs. However, if a radiopaque luting cement is used in conjunction with the latter material (Cerec Vita Blocks) this will allow detection of recurrent caries, but detection of marginal overhangs will still be difficult to achieve. It is interesting to note that Vita VMK has radiopacity greater than that of Cerec Vita Blocks; however, its radiopacity is only comparable to that of dentine. Both composites had radiopacities greater than that of enamel which indicates their radiographic suitability for use in posterior teeth. The radiopacity values reported in this study for enamel and dentine (1.84 mm Al/l.0 mm enamel and 1.16 mm Al/ 1.0 mm dentine) are comparable to those reported by Williams and Billington (1987) (2.1 mm Al/l.0 mm enamel and 1.0 mm Al/l.0 mm dentine) and by Stanford et al. (1987) (2.22 mm Al/l.0 mm enamel and 0.70 mm Al/ 1.0 mm dentine). For enamel and dentine sections 2.5 mm thick, Abou-Tab1 et al. (1979) reported radiopacity values
Table 1. Materials tested and their radiopacity expressed as equivalent thickness of aluminium. Bar indicates materials not significantly different Optical density
Radiopacity (mm AV2.5 mm material)
Radiopacity (mm Al/l. 0 mm material)
Material
Mean
s.d.
Occlusin Uni-tips
0.541
0.032
z
2.84
lsosit Dicer MGC Enamel Vita VMK 68 Dentine Cerec Vita Blocks
0.647 0.664 0.767 0.963 1.006 1.206
0.039 0.034 0.043 0.043 0.059 0.053
5:5 4.6 3.1 2.9 1.9
2.32 2.20 I 1.84 1.24 1.16 0.76
368
J. Dent
199 1; 19:
No. 6
Table II. Radiopacity of the tested materials when film exposure was conducted at 70 kVp instead of 65 kVp Material Occlusin Uni-tips lsosit Dicer MGC Enamel Vita VMK 68 Dentine Cerec Vita Blocks
Radiopacity in mm Al 7.8 5.9 5.8 4.4 3.3 2.8 1.9
of 4.0 mm Al and 2.5 mm Al for enamel and dentine, respectively. These values are also comparable to the values reported in the present study (4.6 mm Al for enamel and 2.9 mm Al for dentine). Variations in radiopacity values between different studies can be due to a number of factors which include: speed of the film used, exposure time, voltage used and processing of the film. For example, in the present study when the radiopacities of the same specimens of materials were measured under the same conditions with the exception of using a voltage of 70 kVp instead of 65 kVp, slightly different values were obtained (Table Ir). Although the pattern of the variations among these values is not uniform, the magnitude of the variations is very small and insignificant and most important the ranking of the materials remains unchanged. Other factors mentioned above may influence the radiopacity values to a greater extent. However, for comparative studies like the present one, variations in the radiopacity values of the examined materials as related to values reported in other studies will have no bearing on the ranking of the materials within the individual study. It is concluded that the Dicer MGC material has the
radiopacity required for use as a posterior intracoronal ceramic restorative material, whereas the application of Cerec Vita Blocks as an intracoronal posterior restorative is dependent on the radiopacity of the luting cement for the purpose of recurrent caries detection. Acknowledgements The authors of this article would like to thank the Siemens Company, Canada for their supply of the ceramic inlay materials.
References Abou-Tab1 Z. M., Tidy D. C. and Combe E. C. (1979) Radiopacity of composite restorative materials. Br. Dent. J. 147, 187-188. Cook W. D. (1981) An investigation of the radiopacity of composite restorative materials. Aust Dent J. 26, 105-l 12. Deines D. N. (1986) The etched porcelain inlay/onlay restoration. Missouri Dent. .l. 66, 26-28. Goshima T. (1985) The radiopacity of composite restorative materials. Dentomaxillofac. Radiol. (suppl. 7, abstr. 79). Huff M. D. (1928) Porcelain inlays and their substitutes. J. Am. Dent Assoc. 15, 1505-1508. Lutz R. W., Phillips R. W., Roulet J. F. et al. (1984) In vivo and in vitro wear of potential posterior composites. J. Dent. Res. 63, 914-920. Omer 0. E., Wilson N. H. F. and Watts D. C. (1986) Radiopacity of posterior composites. J. Dent. 14, 178-179. Qualtrough A J. E., Wilson N. H. F. and Smith G. A (1990) The porcelain inlay: a historical view. Oper. Dent. 15, 61-70. Stanford C. M., Fan P. L. and Schoenfeld C. M. (1987) Radiopacity of light-cured posterior composite resins. J. Am. Dent. Assoc. 115,722-724. Williams J. A. and Billington R. W. (1987) A new technique for measuring the radiopacity of natural tooth substance and restorative materials. J. Oral Rebabif. 14, 267-269.
Book Review Periodontics: A Practical Approach. J. B. Keiser. Pp. 544. 1990. Oxford, Wright (an imprint of Butterworth-Heinemann). Hardback, f 65.00 The author of Periodontics: A Practical Approach is Dr J. Bernard Keiser, Senior Lecturer and Honorary Consultant in Periodontology at the Eastman Dental Hospital in London. The author’s intent was an effort to combine current findings in clinical and basic research in periodontology with his 25 years of clinical experience to suggest a practical approach to therapy. The book is divided into three parts, each with specific objectives and characteristics. Pat-t I is devoted to the basics of periodontal disease and is authored by eminent contributors in the field. The topics covered include: the periodontium in health and disease; pathogenesis, microbiology and epidemiology of periodontal disease; and health education including plaque control. The material is thoroughly reviewed and is ‘state of the art’; however, supporting scientific data could have been included rather than providing a list of pertinent literature at the end of each chapter in the limited section of, ‘References for further study’. Part II describes therapeutic techniques recommended by the author for the treatment of various periodontal conditions and is illustrated clearly with diagrams and sequential
photographs. The 19 chapters of this section begin with the author’s rationale for periodontal therapy, including surgical and non-surgical treatment, and conclude with the maintenance phase of this therapy. The section on surgical therapy is interesting as it includes the author’s own classification and nomenclature of various procedures, concepts which are unsupported by references or resources for further reading. These personal views comprise approximately 75 per cent of the book. Part III presents a review of current research findings to support the clinical approach recommended in Part II. These chapters present extensive reviews of pertinent topics and are supported by excellent citations. It is unfortunate that the author did not combine Parts II and III since this would have combined the discussion of current scientific information with the therapy recommended. Such an approach would have better integrated the contents of the book, resulting in a more cohesive text and avoiding the minor inconsistencies. Nonetheless, it does represent a good source of information for practitioners and students alike on the practice of periodontics, presenting the clinical approach to periodontal treatment of an experienced clinician, while thoroughly reviewing current scientific findings. R. G. Caffesse
