calcium and phosphate metabolism and its prosthodontics implications.

1. Calcium and Phosphate
Metabolism
Presenter:
Dr. Aastha Subba
Junior Resident
Department of Prosthodontics
And Crown-Bridge
BPKIHS, Dharan

2. ü Introduction
ü Functions of Calcium and phosphate
ü Dietary sources of Calcium and phosphate
ü Recommended Dietary Allowance for Calcium and
phosphate
ü Factors regulating serum calcium and phosphate
levels
ü Prosthodontic implications of disorders associated
calcium and phosphate
Contents

3. * Calcium is the most abundant mineral in the
body.
* It is classified chemically as one of the
alkaline earth elements with the atomic
number- 20, atomic weight- 40.08,atomic
symbol- Ca and oxidation state- 2.
Introduction

4. * The body of a young adult human contains
about 1100 g (27.5 moles) of calcium.
* About 98% of the calcium in the human body is
found in bones.
* The remaining 2% is involved in a number of
processes such as signaling, muscle
contraction, and blood clotting.

5. Ø The calcium in bone is of two types:
a. a readily exchangeable reservoir: regulates
plasma Ca2+, providing for the movement of
about 500 mmol of Ca2+ per day into and out
of the readily exchangeable pool in the
bone.
c. much larger pool of stable calcium that is
only slowly exchangeable: involves bone
remodeling by the constant interplay of
bone.

7. Ø Plasma calcium, normally at a concentration of
around 10 mg/dL, is partly bound to protein and
partly diffusible.
Ø The free, ionized calcium (Ca2+) in the body
fluids is a vital second messenger and is
necessary for blood coagulation, muscle
contraction, and nerve function.

9. Functions of Calcium

10. Overview
of
absorption and
excretion of Calcium

12. Committee to Review Dietary Reference Intakes for Vitamin D and Calcium, Food and Nutrition Board, Institute of Medicine. Dietary
Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academy Press, 2010.

13. Dietary sources of Calcium

15. Factors Regulating the
Plasma calcium level
• Vitamin D
• Parathyroid Hormone
• Calcitonin

16. * Vitamin D are a group of sterols that have
a hormone-like function.
* Exists in two inactive forms
q VitaminD2 (Ergocalciferol)
q Vitamin D3 (Cholecaliferol)
A. Vitamin D (Calcitriol)

17. * The active form of Vitamin D is 1,25
dihydroxycholecalciferol or calcitriol.
* The normal range of the total 25(OH)D level in
the plasma is 25-80 ng/mL.
A. Vitamin D (Calcitriol)

19. Functions of Vitamin D

20. * Vitamin D leads to formation of calbindin, a
calcium-binding protein, in the intestinal
epithelial cells.
* This protein functions in the brush border of
these cells to transport calcium into the cell cyto-
plasm.
How does Vitamin D increase Serum
Ca2+ level?

21. * It also increases the
number of Calcium
s t i m u l a t e d A T P a s e
thereby increasing the
overall capacity for
absorption of dietary
calcium.

22. * Calcitriol facilitates Ca2+
reabsorption in the kidneys
thus decreasing the
excretion of Calcium in the
urine.

23. Ø The stimulation of
osteoblasts brings
about a secondary
increase in the
a c t i v i t y o f
osteoclasts.

24. * the plasma concentration of 1,25-
dihydroxycholecalciferol is inversely affected
by the concentration of calcium in the plasma
Effect of Calcium in the formation of
Calcitriol

26. Parathyroid hormone is a
protein hormone secreted
by chief cells of parathyroid
gland.
It is originally synthesized as
preproPTH which is
degraded to proPTH and
finally to active PTH.
B. Parathyroid hormone (PTH)

27. Functions of Parathyroid Hormone

28. Control of Parathyroid Secretion by
Calcium Ion Concentration

29. C. Calcitonin
* Calcitonin is a peptide hormone secreted by
the parafollicular cells, or C cells of the thyroid
gland.
* Calcitonin tends to decrease plasma calcium
concentration and, in general, has effects
opposite to those of PTH.

30. Functions of Calcitonin

31. Calcium Homeostasis
Summary

34. Phosphate
* Total body phosphorus is 500–800 g.
* Approximately 85 percent of the body’s
phosphate is stored in bones.
* 14 to 15 percent is stored in the cells, and
* less than 1 percent is in the extracellular fluid .

35. * Inorganic phosphate in the plasma is mainly is
in two forms:
a) HPO42-
b) H2PO4−.
* The normal serum phosphorus concentration is
3.4 to 4.5 mg/dl.

36. Overview
of
absorption and excretion
of Phosphate

38. Role of Parathyroid
hormone in Phosphate
metabolism

40. Dietary sources of Phosphate

41. Published in Annual review of nutrition 2017
Dietary Phosphorus Intake and the Kidney.
Alex R Chang, Cheryl Andersonv

42. Functions of Phosphate
* It builds and repairs the bone and teeth.
* It forms the part of adenine and guanine of
nucleoside
* It is an essential element in the cellular structure,
cytoplasm, and mitochondrium.
* It is necessary for several enzymatic processes in
glycolysis, ammonia-genesis as well as in oxidative
phosphorylation, resulting in energy from the
formation of ATP from ADP.

43. * Calcium : Phosphate ratio normally is between
1:1 and 2:1
* Increase in plasma calcium level causes
corresponding decrease in absorption of
phosphate.
* This ratio is always constant.
Calcium : Phosphate Ratio

44. * processed foods are abundant in phosphorus
with very less amount of calcium.
* A high dietary phosphorus intake is suggested
to have negative effects on bone through
increased PTH secretion, as high serum PTH
concentration increases bone resorption and
decreases bone formation.

46. Conditions Affecting the Calcium
and Phosphate metabolism that
have Prosthodontic Implications

47. * Osteoporosis is a metabolic disease characterized by
low bone mass and micro-architectural deterioration
of bone tissues leading to enhanced bone fragility and
increased fracture risk.
Osteoporosis
Osteoporotic bone

49. Osteoporosis
Primary
Type I
Post-
menopausal
Type II
Age related
Secondary

50. * Kribbs, in his study, found a greater tooth loss
and a greater number of edentulous subjects in
the osteoporotic group, reporting an average
of 6.9 teeth lost in latter population compared
to 4.5 teeth in the normal population.
Prosthodontic Implications of
Osteoporosis

51. * Mandibular bone mass was found to be
significantly greater in the normal group
compared to osteoporotic group.
* A study of osteoporotic women over the age of
50 years indicated that they required new
dentures three times more frequently than
women of the same age not suffering from
clinical osteoporosis.

52. * Hirai et al. found that the presence of skeletal
osteoporosis strongly affected resorption of
the ridges in edentulous patients.
* A review published by Wactawski-Wende found
correlations between osteoporosis and
periodontal disease.

53. * They stated that loss of bone density in the jaws
(as in osteoporosis) provided a host system,
which was more vulnerable to infectious
destruction of the periodontal tissues.
* Osteoporosis may contribute to resorption in
both condylar and temporal components of the
temporomandibular joint, which could lead to
its dysfunction, and pathogenic fractures.

54. * Screening for osteoporosis before providing
any prosthodontic treatment should be
considered essential as conventional treatment
may further aggravate bone loss.
* Management of osteoporosis followed by
modifications in the treatment plan to reduce
the stresses on jaw bones is recommended.
Prosthodontic Management

55. * For removable dentures, mucostatic and open
mouth impression techniques are to be used.
* use of acrylic non- or semi-anatomic teeth
rather than porcelain ones is preferred
* narrowing the occlusal table and/or decreasing
number of posterior teeth should be
considered

56. * periods of extended tissue rest by keeping
dentures out of the mouth for 10–12 h daily
* optional use of soft liners and shorter recall
intervals to facilitate early intervention could be
incorporated.

57. * metal denture bases exhibits the greatest
reduction in alveolar ridge height in comparison
with soft-lined denture bases showing the least
reduction probably due to its dampening action
* Some studies suggest that fixed partial dentures
may be avoided until treatment for osteoporosis
is instituted, as it may accentuate alveolar bone
loss in periodontally compromised abutment
areas.

58. Dental Implants and Osteoporosis

59. * Shibili et al. performed a comparative
histological analysis between implants with
load removed in patients with and without
osteoporosis.
* The percentages of bone- implant contact did
not show differences between both groups.
* The histomorphometric results were not
different either between groups once the
osseointegration was established.

60. * In a study to evaluate osseointegration in
postmenopausal women aged between 48 and
70, 19 of them with a diagnosis of osteoporosis
and 20 whose diagnosis was normal, 82
mandibular implants were placed (39 in the
osteoporosis group and 43 in the control
group) and osseointegration was analysed after
9 months.

61. * Results determined by panoramic x-rays
showed no significant differences between the
group of osteoporosis and the control group.
* Also histological analysis of jaw biopsies
showed no differences in bone formation and
bone resorption between the two groups.

62. * In another retrospective study with a follow up
to 3 years and 4 months for 70 implants placed
in patients diagnosed with osteoporosis at
lumbar level of the spine and hip, there was a
success rate of 97% for the maxilla and 97.3% for
jaw.

63. * Thus, it is feasible to place implants in subjects
with osteoporosis, with success rates similar
to those obtained in healthy subjects, even in
cases in which there was poor quality of bone
during implant placement.

64. Bisphosphonates and Implants

65. * The BP inhibit the resorptive activity of
osteoclasts by inducing their apoptosis and
preventing their formation from hematopoietic
precursors.
* One of the most serious complications of BP
therapy is Bisphosphonate Related
Osteonecrosis of the Jaws (BRONJ).

66. * Javed and Almas in their study showed that the
incidence of implant failure was minimal in
patients using oral and intravenous
bisphosphonates, and concluded that dental
implants in patients undergoing BPs therapy
can Osseo-integrate and remain functionally
stable.
Bisphosphonate treatment and dental implants: A systematic review
Med Oral Patol Oral Cir Bucal. 2016 Sep 1;21 (5):e644-51.

67. * Mínguez-Serra et al. suggested the avoidance
of dental implant procedures in patients that
have been receiving intravenous BPs.
* This was in accordance with the results where
cases with related combined use of oral and
intravenous BP, developed osteonecrosis.
Bisphosphonate treatment and dental implants: A systematic review
Med Oral Patol Oral Cir Bucal. 2016 Sep 1;21 (5):e644-51.

68. * Bell and Bell had a success rate of 95% in 100
dental implants installed in 42 patients taking
oral bisphosphonates and they did not present
signs of osteonecrosis of the jaws.
* The study of Yip et al. indicated that women
with implant failure had increased odds of
reporting a history of oral bisphosphonate use
compared with those without implant failure.

69. * Lazarovici et al. followed 27 patients who
developed BRONJ associated with dental
implants and concluded that this condition is a
side effect of BPs treatment presented like a
late complication.
* They suggested that patients undergoing
bisphosphonate therapy who received dental
implants should be followed for long periods.

71. * Patients who take oral bisphosphonates, can
be submitted to dental implant surgery, on the
condition that the risks are thoroughly
assessed.
* If a dental implant surgery is proposed,
informed consent should be provided reporting
about the possible of long-term implant failure
and the risk of developing osteonecrosis of the
jaws.
Therefore,

72. * regular dental follow-up is must.
* The risk of developing BRONJ as well as loss of
implant is greater in patients under intravenous
bisphosphonate therapy.
* Out of the 528 patients with history of BP use
where with 1330 implants were placed
Bisphosphonate treatment and dental implants: A systematic review
Med Oral Patol Oral Cir Bucal. 2016 Sep 1;21 (5):e644-51.

73. * There were 113 loss of implants (8.49%) in BP
users and 78 cases of osteonecrosis (14.77%).
* Thus, it was suggested that dental implant
treatment should be suspended, whenever
possible in patients who are under BP therapy.
Bisphosphonate treatment and dental implants: A systematic review
Med Oral Patol Oral Cir Bucal. 2016 Sep 1;21 (5):e644-51.

74. Calcium, Vitamin D and Residual
Ridge Resorption .

75. * A study investigating the relationship between
dietary calcium and phosphorus and alveolar bone
resorption in edentulous patients was done.
* Subjects were divided into two groups:
a. Those who had experienced minimal alveolar
resorption.
b. Those who showed evidence of more severe
resorption by the loss of more than one third of
their mandibular height.
* 14 day record of meals was made by each subject
which was then analysed.
Wical, K. E., and Swoope, C. C.: Studies of residual ridge resorption, Part II. The relationship of dietary calcium and
phosphorus to residual ridge resorption. J PROSTHET DENT. 32:13, 1974.

76. * When the diets of subjects with minimal bone
resorption were compared with the diets of
subjects with severe alveolar destruction it was
found that
ü Subjects in the minimal-resorption group
were obtaining more than 800 mg. of calcium
daily
ü Subjects in the severe-resorption group were
taking less than 600 mg. of calcium daily.

77. * Most of the subjects in the group with minimal
resorption have Ca/P ratios above the 0.7 level.
* While most of those from the second group
have Ca/P ratios below 0.7.
* Thus, the study suggested that a correlation
exist among low calcium intake, low calcium/
phosphorus ratios, and alveolar bone
resorption.

78. * A study conducted to test the hypothesis that
“daily calcium and vitamin D supplement would
tend to reduce the rate and extent of alveolar
bone resorption following extraction of teeth”
suggested
ü that the rate and severity of alveolar ridge
resorption are related to the adequacy of the
calcium intake and the calcium-phosphorus ratio of
the diet.
Kenneth E. Wical Peter Brussee; Effects of a calcium and vitamin D supplement on alveolar ridge
resorption in immediate denture patients; J PROSTHET DENT. 14:1, 1979

79. ü Patients whose diet is deficient in calcium, a
significant degree of protection against the
undesirable resorption of alveolar bone can be
gained from consistent use of the supplements
containing calcium and vitamin D.
Kenneth E. Wical Peter Brussee; Effects of a calcium and vitamin D supplement on alveolar ridge
resorption in immediate denture patients; J PROSTHET DENT. 14:1, 1979

80. * Serum inorganic phosphate concentration <2.5 mg/
dl is called as Hypophosphataemia
* Hypophosphatemia enhances the synthesis of 1,
25-dihydroxycholeclaciferol which is the active
metabolite of vitamin D and stimulates bone
resorption.
* Hyphophosphatemia is one of the factors
contributing to residual ridge resorption
Hypophosphatemia

81. Patient is on steroids.
Should we worry?

83. * A retrospective study was conducted in
patients treated with dental implants while
receiving glucocorticosteroid therapy for
various systemic diseases, where a
conventional two-stage surgical protocol was
used, without bone regeneration procedures.
Petsinis V, Kamperos G, Alexandridi F, Alexandridis K. The impact of glucocorticosteroids
administered for systemic diseases on the osseointegration and survival of dental implants placed
without bone grafting-A retrospective study in 31 patients. J Craniomaxillofac Surg. 2017;45(8):1197-
1200.

84. * The osseointegration was clinically and
radiographically tested at the uncovering of the
implants.
* The follow-up after loading was set at a
minimum of 3 years.
Results:
ü Of the 105 dental implants placed, 104 were
osseointegrated (99%).
ü No bone absorption was radiographically noted
at the uncovering of the osseointegrated
implants.

85. Conclusions:
* Glucocorticosteroid intake for systemic diseases
does not have a significant impact on the
osseointegration.
* Therefore, it should not be considered a
contraindication for dental implant placement.

86. * A disorder of the bone remodeling process, in
which the body absorbs old bone and forms
abnormal new bone.
* Also known as osteitis deformans.
* Commonly seen in age groups above 40 years.
Pagets Disease of Bone

87. * Paget's disease affects dentate and edentulous
patients.
* The upper jaw is more frequently involved that
the lower jaw.
* Dentists may be the first to detect this disease.
* Dental manifestations may be seen as
enlargement of one or both alveolar ridges,
malocclusion, flattening, and widening of the
palate, diastemas, or loosening and migration of
teeth.

88. * The increase in the bulk of the residual alveolar
ridges in edentulous patients necessitates
frequent adjustments and replacement of
dentures.
* Increased size of the arch may even make it
difficult for the patient to close the lips over the
protruded oral structures.
* Surgical reductions of excessively enlarged
ridges may be necessary.

89. * Edentulous patients should be re-examined
periodically as enlargement of the ridges may
cause dentures to fracture, as well as cause
pressure on the supporting tissues.
* The result may be ulceration or necrosis of the
soft and hard tissues.

90. * Calcium and phosphorus are vital for the proper
development and maintenance of calcified oral tissues.
* Of the many systemic influences which affect the bone
responses of patients, dietary factors may be subject
to the dentist’s control.
* Nutritional deficiencies and imbalances, as well as
mechanical factors, should receive consideration in
diagnosis and treatment planning for dental patient.
Conclusion

91. * Text book of medical physiology , 11th Edi. , Guyton and
Hall , Elsevier
* Textbook of Medical Physiology, 22nd edition, Ganong,
Elsevier
* Renal Control of Calcium, Phosphate, and Magnesium
Homeostasis, Judith Blaine, Michel Chonchol, Moshe Levi,
CJASN Jul 2015, 10 (7) 1257-1272;
* Smith BJ, Eveson JW. Paget's disease of bone with
particular reference to dentistry. J Oral Pathol.
1981;10(4):233-247.
References
.

92. * de-Freitas NR, Lima LB, de-Moura MB, Veloso-Guedes CC, Simamoto-
Júnior PC, de-Magalhães D. Bisphosphonate treatment and dental
implants: A systematic review. Med Oral Patol Oral Cir Bucal.
2016;21(5):e644-e651.
* Singh SV, Tripathi A. An overview of osteoporosis for the practising
prosthodontist. Gerodontology. 2010;27(4):308-314.
* Kenneth E. Wical Peter Brussee; Effects of a calcium and vitamin D
supplement on alveolar ridge resorption in immediate denture
patients; J PROSTHET DENT. 14:1, 1979
* Petsinis V, Kamperos G, Alexandridi F, Alexandridis K. The impact of
glucocorticosteroids administered for systemic diseases on the
osseointegration and survival of dental implants placed without
bone grafting-A retrospective study in 31 patients. J Craniomaxillofac
Surg. 2017;45(8):1197-1200.